U.S. patent application number 12/795929 was filed with the patent office on 2010-12-09 for mri-guided surgical systems with preset scan planes.
Invention is credited to Michael Guttman, Kimble L. Jenkins, Peter Piferi, Kamal Vij.
Application Number | 20100312094 12/795929 |
Document ID | / |
Family ID | 43301224 |
Filed Date | 2010-12-09 |
United States Patent
Application |
20100312094 |
Kind Code |
A1 |
Guttman; Michael ; et
al. |
December 9, 2010 |
MRI-GUIDED SURGICAL SYSTEMS WITH PRESET SCAN PLANES
Abstract
The systems include a display with a User Interface in
communication with a circuit, the display is configured to display
a patient model/map or model of target anatomical structure. The
User Interface is configured to allow a user to select at least one
target site (e.g., ablation site) on the model/map whereby scan
planes for a corresponding location in 3-D space for the selected
target ablation site are pre-set for future use. The circuit can be
configured to automatically direct the MRI Scanner to use the
pre-set scan planes to obtain MR image data when an intrabody
device such as an ablation catheter is at the location that
corresponds with the selected target site.
Inventors: |
Guttman; Michael; (Potomac
Falls, VA) ; Jenkins; Kimble L.; (Memphis, TN)
; Piferi; Peter; (Orange, CA) ; Vij; Kamal;
(Chandler, AZ) |
Correspondence
Address: |
MYERS BIGEL SIBLEY & SAJOVEC
PO BOX 37428
RALEIGH
NC
27627
US
|
Family ID: |
43301224 |
Appl. No.: |
12/795929 |
Filed: |
June 8, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61185072 |
Jun 8, 2009 |
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61187323 |
Jun 16, 2009 |
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61219638 |
Jun 23, 2009 |
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61261103 |
Nov 13, 2009 |
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Current U.S.
Class: |
600/411 |
Current CPC
Class: |
A61B 2034/101 20160201;
A61B 2017/00053 20130101; A61B 34/25 20160201; A61B 2017/00243
20130101; A61B 2018/00839 20130101; A61B 5/415 20130101; A61B 34/10
20160201; A61B 2018/00029 20130101; A61B 5/055 20130101; A61B
2018/1472 20130101; A61B 2034/107 20160201; A61B 34/20 20160201;
A61B 18/1492 20130101; A61B 2034/105 20160201; A61B 2034/252
20160201; A61B 5/418 20130101; A61B 2034/2051 20160201; A61B
2090/374 20160201 |
Class at
Publication: |
600/411 |
International
Class: |
A61B 5/055 20060101
A61B005/055 |
Claims
1. An MRI guided system, comprising: a circuit; and a display in
communication with the circuit, the display having a User Interface
(UI), the display configured to display a volumetric planning model
of a target anatomical structure of a patient, wherein the UI is
configured to allow a user to select at least one target site on
the planning model, and wherein the circuit associates at least one
pre-set scan plane for the at least one selected target site for
subsequent use.
2. The system of claim 1, wherein the circuit is in communication
with an MR Scanner having a 3-D imaging space with a coordinate
system, and wherein the circuit is configured to electronically
register the planning model to the 3-D MRI imaging space to define
the at least one pre-set scan plane used by the MR Scanner based on
the selected at least one selected site on the registered planning
model.
3. The system of claim 1, wherein the circuit is configured to
allow a user to select one of a plurality of different pre-defined
surgical procedures, each procedure having a defined set of
proposed target treatment sites that can be electronically
automatically placed on the planning model as the target sites.
4. The system of claim 1, wherein the circuit is configured to
provide an adjustable template or grid of suggested target
treatment sites that is electronically applied to the planning
model.
5. The system of claim 2, wherein the circuit is configured to
automatically electronically direct the MRI Scanner to use the at
least one pre-set scan plane associated with a corresponding
selected target site to obtain an image slice of MR image data when
a distal end portion of an intrabody device is determined to be
proximate a location that corresponds to the selected target
site.
6. The system of claim 1, wherein the planning model is an
interactive model, and wherein the UI is configured to allow a user
to rotate the planning model and electronically mark target sites
to select the target sites at different locations.
7. The system of claim 1, wherein the circuit is configured to
present suggested scan planes that will generate at least one image
slice that will include relevant local tissue associated with the
at least one selected target site based on a contour of the
tissue.
8. The system of claim 1, and wherein, in response to the user
selection of the at least one target site on the planning model,
the circuit also electronically associates a corresponding 3-D
perspective viewing window of the model that is subsequently
automatically displayed during an MRI guided procedure when an
intrabody device is at the location in the body that corresponds to
the selected target site.
9. The system of claim 1, wherein the display comprises a viewing
window with near real-time MR images of local tissue being actively
treated by an intrabody device, wherein the circuit generates the
near real-time MR images using at least one pre-set scan plane
associated with a selected target site having a location that is
proximate a calculated location of a distal end portion of the
intrabody device.
10. The system of claim 2, further comprising at least one
intrabody device with at least one tracking coil connected to a
channel of an MR Scanner, wherein the circuit comprises dimensional
and/or configuration data about the device, and wherein the circuit
directs the MR Scanner to obtain an image slice of relevant local
tissue using the at least one preset scan plane associated with a
seleted target site having a location that is proximate a
calculated location of a distal end portion of the intrabody
device.
11. The system of claim 10, wherein the image slice includes tissue
at a location that is a defined distance beyond the intrabody
device.
12. The system of claim 1, wherein the at least one target site is
a plurality of target treatment sites, each having a corresponding
at least one pre-set scan plane.
13. The system of claim 3, wherein the selectable procedures
include different cardiac arrhythmias, each with a different
suggested ablation pattern, and wherein the circuit electronically
applies the suggested ablation pattern with the target treatment
sites for a selected procedure to the planning model that can be
electronically adjusted by a user.
14. The system of claim 9, wherein the intrabody device is an
injection catheter comprising a therapeutic agent for treating
congestive heart failure.
15. The system of claim 4, wherein the grid or template has an
adjustable suggested ablation pattern of at least one transmural
lesion to create a conduction block that can be electronically
applied to the planning model.
16. The system of claim 1, wherein the circuit is configured to
electronically apply a suggested grid or template that is
automatically adjusted to fit patient contour based on anatomical
features electronically located in or on the planning model.
17. The system of claim 1, wherein the system is a cardiac system,
and wherein the system comprises a therapeutic catheter with a
plurality of spaced apart tracking coils on a distal end portion
thereof, wherein the at least one selected target site comprises a
plurality of spaced apart target treatment sites associated with
different associated pre-set scan planes, and wherein the circuit
is configured to track location of the therapeutic catheter in 3-D
MRI image space and render a physical representation of the distal
end portion of the catheter in a visualization on the display, and
wherein the circuit is configured to render the visualization to
show the catheter location with respect to a rendered patient
volumetric model of the heart.
18. The system of claim 17, wherein the circuit is configured to
show near real time MRI image data on the display during an MRI
guided injection or ablation therapy carried out by the therapeutic
catheter using the at least one pre-set scan plane for a respective
selected target treatment site.
19. The system of claim 17, and wherein the patient volumetric
model in the visualization can comprise a tissue characterization
model and/or an electroanatomical model or data therefrom.
20. The system of claim 1, wherein the circuit is configured to
generate suggested scan planes and show them on the display with
respect to the planning model and the at least one target site.
21. The system of claim 1, wherein the circuit is configured to
provide the planning model without the planning model registered to
3-D MRI image space, and wherein the circuit is configured to
associate the pre-set scan planes with the planning model then
register the planning model with the associated pre-set scan planes
to 3-D MRI image space at a subsequent time.
22. The system of claim 21, wherein the circuit identifies spatial
coordinates of the pre-set scan planes based on the registered
planning model.
23. An MRI guided system, comprising: a circuit integrated into
and/or communicating with a clinician workstation, the workstation
comprising a display with a User Interface, the display configured
to display at least one patient volumetric model of target anatomy,
wherein the User Interface is configured to allow a user to select
target sites on the at least one displayed model, wherein the
circuit electronically associates pre-set scan planes for an MRI
Scanner for the selected target sites for future use.
24. The system of claim 23, wherein the system is a cardiac
treatment system, and the patient model is a model of at least a
portion of the patient's heart, wherein the circuit is configured
to register the model to 3-D imaging space associated with an MR
Scanner for an MRI-guided interventional procedure and
electronically direct the MRI Scanner to use at least one of the
pre-set scan planes to obtain near real time MR image data when a
therapeutic or diagnostic catheter is proximate a location in the
heart corresponding to a respective at least one selected target
site associated with the at least one scan plane.
25. A method for carrying out an MRI-guided procedure, comprising:
displaying a volumetric model of a target patient anatomical
structure; electronically identifying at least one target site on
the displayed model; registering the model to 3-D MRI imaging space
after the identifying step and before or during introducing an
intrabody device into the patient during an MRI guided procedure;
electronically associating at least one pre-set MRI image scan
plane for a respective identified target site after the registering
step; guiding the intrabody device with at least one tracking coil
to a target intrabody location using near real time MR image data
and tracking coil signal data generated by the at least one
tracking coil; automatically electronically using the at least one
pre-set scan plane associated with one of the at least one
identified target sites to obtain near real time MR image data when
a distal end portion of the intrabody device is determined to be
proximate a corresponding location in the body based on the
tracking coil signal data; treating and/or evaluating target tissue
using the intrabody device; and displaying near real-time MR images
of the target tissue during the guiding, treating and/or evaluating
steps using the obtained MR image data.
26. The method of claim 25, wherein the at least one target site is
a plurality of spaced apart target injection or ablation treatment
sites, and wherein the step of displaying the near real-time MR
images of tissue being treated is carried out to show near
real-time MR images of tissue being injected or ablated.
27. The method of claim 25, wherein the MR images comprise a close
up view of high resolution MR images of the target tissue in
adjacent en face and side views.
28. The method of claim 25, wherein the target anatomy is cardiac
tissue for treating cardiac disorders, the method further
comprising: displaying a post-treatment model of the patient's
anatomical heart structure; accepting user input to select target
sites on the post-treatment model to select at least one additional
treatment site for clean-up to facilitate desired therapeutic
coverage or a complete lesion pattern formation for electrical
isolation; electronically defining a pre-set scan plane for the
selected at least one additional treatment site; automatically
electronically using the at least one pre-set scan plane associated
with the additional target treatment site when a distal end portion
of the intrabody device is determined to be proximate a
corresponding location in the heart to obtain near real time MR
image data; treating the additional treatment site; and displaying
near real-time MR images of the target tissue during the treating
step using the obtained MR image data.
29. A computer program product for facilitating an MRI-guided
procedure of a patient, the computer program product comprising: a
non-transitory computer readable storage medium having computer
readable program code embodied in the medium, the computer-readable
program code comprising: computer readable program code that
defines at least one pre-set scan plane for a respective target
site based on a user's marking and/or selection of a least one
target site on a model of a patient's target anatomical structure
via a User Interface.
30. The computer program product of claim 29, wherein the computer
readable program code that defines the at least one pre-set scan
plane is configured to provide an interactive model of the
patient's anatomical structure as the model.
31. The computer program product of claim 29, further comprising
computer readable program code that generates suggested scan planes
that cover tissue associated with a target site based on a contour
of tissue proximate the at least one defined target site.
32. The computer program product of claim 29, wherein the computer
readable program code that defines at least one scan plane is
configured to define a plurality of different scan planes for
spaced apart treatment sites associated with an ablation pattern
for treatment of cardiac arrhythmias.
33. The computer program product of claim 29, further comprising a
menu of user selectable cardiac arrhythmia conditions with
associated pre-defined suggested ablation patterns, wherein a user
via the User Interface can select one of the conditions and the
corresponding suggested ablation pattern is applied to the model to
provide suggested target sites.
34. The computer program product of claim 29, wherein the computer
readable program code that defines at least one scan plane is
configured to define a plurality of different scan planes for
spaced apart treatment sites associated with target injection sites
for treatment of heart failure.
35. An MRI cardiac interventional system, comprising: a display; a
processor in communication with the display; electronic memory
coupled to the processor; and computer program code residing in the
memory that is executable by the processor for: displaying a
graphical user interface (GUI) containing at least one anatomical
model of at least a portion of the heart within the display,
wherein the GUI allows a user to select target sites on the model;
and defining associated pre-set scan planes for the selected target
sites.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to U.S.
Provisional Application Ser. No. 61/185,072 filed Jun. 8, 2009,
U.S. Provisional Application Ser. No. 61/187,323 filed Jun. 16,
2009, U.S. Provisional Application Ser. No. 61/219,638 filed Jun.
23, 2009, and U.S. Provisional Application Ser. No. 61/261,103
filed Nov. 13, 2009, the contents of which are hereby incorporated
by reference as if recited in full herein.
FIELD OF THE INVENTION
[0002] The present invention relates to MRI-guided systems and may
be particularly suitable for cardiac systems, such as cardiac EP
systems for treating Atrial Fibrillation (AFIB).
BACKGROUND OF THE INVENTION
[0003] Conventional Cardiac EP (ElectroPhysiology) Systems are
X-ray based systems which use electroanatomical maps.
Electroanatomical maps are virtual representations of the heart
showing sensed electrical activity. Examples of such systems
include the Carto.RTM. electroanatomic mapping system from Biosense
Webster, Inc., Diamond Bar, Calif., and the EnSite NavX.RTM. system
from Endocardial Solutions Inc., St. Paul, Minn.
[0004] However, there remains a need for MRI-guided systems that
can use MRI to obtain details of tissue not provided by X-ray based
systems and/or to reduce patient exposure to radiation associated
with interventional (diagnostic and/or therapeutic) procedures.
SUMMARY OF EMBODIMENTS OF THE INVENTION
[0005] Some embodiments are directed to MRI guided systems that
include a circuit and a display in communication with the circuit,
the display having a User Interface (UI). The display is configured
to display a volumetric planning model (also referred to
interchangeably as a map) of a target anatomical structure of a
patient. The UI is configured to allow a user to select at least
one target site on the planning model and the circuit defines at
least one pre-set scan plane for the at least one selected target
site for subsequent use. The target site can be a target treatment
site or diagnostic site or a site of interest such as a site used
to form an intrabody path (e.g., septal puncture).
[0006] The circuit can be in communication with (or adapted to
communicate with) an MR Scanner having a 3-D imaging space with a
coordinate system. The circuit can be configured to electronically
register the planning model or image to the 3-D MRI imaging space
with the at least one selected target site so that the at least one
pre-set scan plane is electronically adjusted based on the
registered planning model or image.
[0007] The circuit can be configured to allow a user to select one
of a plurality of different pre-defined surgical procedure options,
each having an associated set of different proposed treatment sites
that in response to user selection can be electronically
automatically placed on the planning model.
[0008] The circuit can be configured to provide an adjustable
template or grid that is electronically applied to the planning
model and provides suggested treatment sites.
[0009] The circuit can be configured to automatically
electronically direct an MRI Scanner to use the at least one
pre-set scan plane associated with a corresponding selected target
site to obtain MR image data when a distal end portion of an
intrabody device is determined to be proximate a location that
corresponds to the selected target treatment site.
[0010] The planning model can be an interactive model. The UI can
be configured to allow a user to rotate the planning model and
electronically mark target sites to select the target sites at
different locations.
[0011] The circuit can be configured to present suggested scan
planes that will generate at least one image slice that will
include relevant local tissue associated with the at least one
selected target site based on a contour of the tissue.
[0012] In some embodiments, in response to the user selection of
the at least one target site on the planning model, the circuit can
also electronically associate a corresponding 3-D perspective
viewing window of the model that is subsequently automatically
displayed during an MRI guided procedure when an intrabody device
is at the location in the body that corresponds to the selected
target site.
[0013] The display can include a viewing window with near real-time
MR images of local tissue being actively treated by an intrabody
device. The circuit can generate the near real-time MR images using
at least one pre-set scan plane associated with a target site
having a location that is proximate a calculated location of a
distal end portion of the intrabody device.
[0014] In some embodiments, the system can include at least one
intrabody device with at least one tracking coil connected to a
channel of an MR Scanner. The circuit can include dimensional
and/or configuration data about the device. The circuit can direct
the MR Scanner to obtain an image slice of relevant local tissue
using the at least one preset scan plane associated with a target
site having a location that is proximate a calculated location of a
distal end portion of the intrabody device. The image slice can
include tissue at a location that is adjacent the interface of the
device and tissue and may include tissue a defined distance beyond
the intrabody device.
[0015] In some embodiments, the at least one target site is a
plurality of target treatment sites, each having a corresponding at
least one pre-set scan plane.
[0016] The selectable procedures, where used, may optionally
include different cardiac arrhythmia procedures. The circuit can
electronically apply a suggested (e.g., contiguous and/or linear)
ablation pattern to the planning model that can be electronically
adjusted by a user.
[0017] The grid or template, where used, may have an adjustable
suggested (e.g., contiguous and/or linear) ablation pattern for
forming transmural lesions that can be electronically applied to
the planning model.
[0018] The circuit may be configured to electronically apply a
suggested grid or template that is automatically adjusted to fit
patient contour based on predefined anatomical features
electronically located in or on the planning model.
[0019] The system can be a cardiac EP system. The system can
include an ablation catheter with a plurality of spaced apart
tracking coils on a distal end portion thereof. The at least one
selected target treatment site can include a plurality of spaced
apart target ablation treatment sites associated with different
associated pre-set scan planes. The circuit can be configured to
track location of the ablation catheter in the heart in 3-D MRI
image space and render a physical representation of the ablation
catheter in a visualization shown on the display. The circuit can
be configured to render the visualization to show the ablation
catheter location with respect to a rendered patient volumetric
model of the heart.
[0020] The circuit can be configured to show near real time MRI
image data during ablation on the display using the at least one
pre-set scan plane for a respective selected target treatment
ablation site.
[0021] The patient volumetric model in the visualization can
comprise a tissue characterization model and/or an
electroanatomical model.
[0022] The circuit can be configured to generate suggested scan
planes and show them on the display with respect to the planning
model and at least one target treatment site.
[0023] The circuit can be configured to provide the planning model
without the planning model registered to 3-D MRI image space. The
circuit can be configured to associate the pre-set scan planes with
the planning model then register the planning model with the
associated pre-set scan planes to 3-D MRI image space at a
subsequent time.
[0024] The circuit can automatically identify spatial coordinates
of the pre-set scan planes based on the registered planning
model.
[0025] Yet other embodiments are directed to MRI guided cardiac
systems. The systems include a clinician workstation in
communication with a circuit or having a circuit. The workstation
includes a display with a User Interface. The display is configured
to display at least one patient volumetric model of the heart. The
User Interface is configured to allow a user to select target
ablation sites on the displayed model. The circuit electronically
associates pre-set scan planes for the selected target ablation
sites for future use.
[0026] The circuit can be configured to register the model of the
heart to 3-D imaging space associated with an MR Scanner and
automatically electronically direct the MRI Scanner to use at least
one of the pre-set scan planes to obtain near real time MR image
data when an ablation catheter is proximate a location in the heart
corresponding to the selected target ablation site associated with
the at least one scan plane during an ablation using the ablation
catheter.
[0027] Still other embodiments are directed to methods for carrying
out an MRI-guided procedure. The methods include: (a) displaying a
volumetric model of a target patient anatomical structure; (b)
electronically identifying at least one target site on the
displayed model; (c) electronically associating at least one
pre-set MRI image scan plane for a respective identified site; (d)
repeating the identifying and associating steps at least once; (e)
registering the model to 3-D MRI imaging space after the
identifying step and before introducing an intrabody device into
the patient during an MRI guided procedure; (f) guiding the
intrabody device to a target intrabody location; (g) electronically
tracking the movement of the intrabody device in 3-D image space;
(h) automatically electronically using the at least one pre-set
scan plane associated with an identified target site when a distal
end portion of the intrabody device is determined to be proximate a
corresponding location in the heart to obtain near real time MR
image data; and (i) displaying near real-time MR images of the
target tissue using the obtained MR image data.
[0028] The at least one target site (e.g., area of interest) can be
a plurality of spaced apart target ablation treatment sites, and
wherein the step of displaying the near real-time MR images of
tissue being treated can be carried out to show near real-time MR
images of tissue being ablated.
[0029] The MR images can include a close up view of high resolution
MR images of the target tissue in adjacent en face and side
views.
[0030] The methods may also include: (j) displaying a
post-treatment model of the patient's anatomical structure heart;
(k) accepting user input to select target sites on the
post-treatment model to select at least one additional treatment
site for ablation clean-up to facilitate complete lesion pattern
formation for electrical isolation; (l) electronically defining a
pre-set scan plane for the selected at least one additional
treatment site; (m) automatically electronically using the at least
one pre-set scan plane associated with the additional target
treatment site when a distal end portion of the intrabody device is
determined to be proximate a corresponding location in the heart to
obtain near real time MR image data; (n) ablating the additional
treatment site; and (o) displaying near real-time MR images of the
target tissue during the ablating step using the obtained MR image
data.
[0031] Yet other embodiments are directed to computer program
products for facilitating an MRI-guided procedure of a patient. The
computer program products include a non-transitory computer
readable storage medium having computer readable program code
embodied in the medium. The computer-readable program code includes
computer readable program code that defines at least one pre-set
scan plane for a respective target treatment site in response to a
user's marking and/or selection of treatment sites on a model of a
patient's target anatomical structure via a User Interface.
[0032] The computer product may also include: (a) computer readable
program code that provides an interactive model of the patient's
anatomical structure to a display; and (b) computer readable
program code that generates suggested scan planes that cover tissue
associated with a target treatment site based on a contour of
tissue proximate the target treatment site.
[0033] The computer readable program code can define a plurality of
different pre-set scan planes for spaced apart treatment sites
associated with an ablation pattern for treatment of cardiac atrial
fibrillation.
[0034] Still other embodiments are directed to MRI cardiac
interventional systems that include: (a) a display; (b) a processor
in communication with the display; (c) electronic memory coupled to
the processor; and (d) computer program code residing in the memory
that is executable by the processor for: (i) displaying a graphical
user interface (GUI) containing at least one anatomical map of at
least a portion of the heart within the display, wherein the GUI
allows a user to select target treatment sites; and (ii) defining
associated pre-set scan planes for the selected target treatment
sites.
[0035] Embodiments of the invention are particularly suitable for
MRI-guided cardiac procedure including cardiac EP procedures for
ablating tissue to treat arrhythmias such as AFIB or injecting
therapeutics to treat heart failure.
[0036] The systems may also be suitable for delivering a
therapeutic agent or carrying out another treatment or diagnostic
evaluation for any intrabody location, including, for example, the
brain, heart, gastrointestinal system, genourinary system, spine
(central canal, the subarachnoid space or other region),
vasculature or other intrabody location.
[0037] It is noted that any one or more aspects or features
described with respect to one embodiment, may be incorporated in a
different embodiment although not specifically described relative
thereto. That is, all embodiments and/or features of any embodiment
can be combined in any way and/or combination. Applicant reserves
the right to change any originally filed claim or file any new
claim accordingly, including the right to be able to amend any
originally filed claim to depend from and/or incorporate any
feature of any other claim although not originally claimed in that
manner. These and other objects and/or aspects of the present
invention are explained in detail in the specification set forth
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The patent or application file contains at least one drawing
executed in color. Copies of this patent or patent application
publication with color drawings will be provided by the Office upon
request and payment of the necessary fee.
[0039] FIG. 1A is a schematic illustration of a display with a User
Interface for defining pre-set scan planes using a patient
anatomical model for MRI-guided procedures according to embodiments
of the present invention.
[0040] FIG. 1B is a schematic illustration of a display with a User
Interface using a deformable grid for defining pre-set scan planes
for MRI-guided procedures according to embodiments of the present
invention.
[0041] FIG. 2A is an exemplary (prophetic) screen shot of a display
with a visualization of map showing a rendered patient model
registered to 3-D MRI image space according to embodiments of the
present invention.
[0042] FIG. 2B is an exemplary (prophetic) screen shot of a display
with a visualilzation showing a planning model registered to 3-D
MRI image space to facilitate an MRI guided procedure according to
embodiments of the present invention.
[0043] FIG. 3 is a schematic illustration of an MRI-guided system
configured to show a device-tissue interface using near RT MRI data
according to embodiments of the present invention.
[0044] FIG. 4 is a schematic illustration of an intrabody device
with a tracking coil electrically connected to a Scanner channel
according to embodiments of the present invention.
[0045] FIG. 5 is a schematic illustration of an MRI system with a
workstation and display according to embodiments of the
invention.
[0046] FIG. 6 is a circuit diagram of an exemplary tracking coil
tuning circuit according to embodiments of the present
invention.
[0047] FIGS. 7A-7D are screen shots of exemplary (prophetic)
interactive visualizations with a physical representation of an
intrabody flexible medical device according to embodiments of the
present invention.
[0048] FIG. 8 is a schematic illustration of a display with two
viewing windows, one showing an interactive visualization and the
other showing prophetic relevant near RT MRI image according to
embodiments of the present invention.
[0049] FIGS. 9 and 10 are prophetic screen shots of exemplary
visualizations and images on a display and UI controls that can be
generated to facilitate an MRI guided procedure according to
embodiments of the present invention.
[0050] FIG. 11 is a screen shot of a display having two viewing
windows one showing target ablation sites on a patient model and
the other showing contemplated (prophetic) near real time
"close-up" MRI images of local tissue, at least the latter images
may be generated using one or more pre-set scan planes according to
embodiments of the present invention.
[0051] FIGS. 12 and 13 are screen shots showing axial and en face
views showing prophetic examples of near real time "close-up" MRI
images of local tissue that may be generated using one or more
pre-set scan planes according to embodiments of the present
invention.
[0052] FIG. 14 is an illustration of a display with a UI and an
interactive patient model that allows a user to select supplemental
ablation sites whereby the circuit/system can identify an
associated pre-set scan plane used by the Scanner when the ablation
catheter is determined to be proximate to the selected supplemental
site according to embodiments of the present invention.
[0053] FIG. 15 is a schematic illustration of an exemplary MRI
cardiac interventional suite according to some embodiments of the
present invention.
[0054] FIG. 16A is an enlarged partial perspective view of a tip
portion of an exemplary ablation catheter according to particular
embodiments of the present invention.
[0055] FIG. 16B is a cross-section of the tip portion of the
catheter taken along lines 16B-16B in FIG. 16A.
[0056] FIG. 17 is an enlarged axial cross section of a tip portion
of another example of an ablation catheter according to embodiments
of the present invention.
[0057] FIG. 18 is an enlarged cross-section of the catheter shown
in FIG. 17.
[0058] FIG. 19 is an enlarged cross-section of the catheter shown
in FIG. 17 taken along lines 19-19 in FIG. 17. The FIG. 18 section
view is taken at a location upstream of that shown in FIG. 19.
[0059] FIG. 20 is a flow chart of exemplary operations that can be
used to carry out embodiments of the present invention.
[0060] FIG. 21 is a schematic illustration of a data processing
circuit or system according to embodiments of the present
invention.
[0061] FIG. 22 is a schematic illustration of a data processing
circuit or system according to embodiments of the present
invention.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0062] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like numbers refer to like
elements throughout. It will be appreciated that although discussed
with respect to a certain embodiment, features or operation of one
embodiment can apply to others.
[0063] In the drawings, the thickness of lines, layers, features,
components and/or regions may be exaggerated for clarity and broken
lines (such as those shown in circuit of flow diagrams) illustrate
optional features or operations, unless specified otherwise. In
addition, the sequence of operations (or steps) is not limited to
the order presented in the claims unless specifically indicated
otherwise.
[0064] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, steps,
operations, elements, components, and/or groups thereof. As used
herein, the term "and/or" includes any and all combinations of one
or more of the associated listed items.
[0065] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the specification and relevant art and
should not be interpreted in an idealized or overly formal sense
unless expressly so defined herein. Well-known functions or
constructions may not be described in detail for brevity and/or
clarity.
[0066] It will be understood that when a feature, such as a layer,
region or substrate, is referred to as being "on" another feature
or element, it can be directly on the other element or intervening
elements may also be present. In contrast, when an element is
referred to as being "directly on" another feature or element,
there are no intervening elements present. It will also be
understood that, when a feature or element is referred to as being
"connected" or "coupled" to another feature or element, it can be
directly connected to the other element or intervening elements may
be present. In contrast, when a feature or element is referred to
as being "directly connected" or "directly coupled" to another
element, there are no intervening elements present. Although
described or shown with respect to one embodiment, the features so
described or shown can apply to other embodiments.
[0067] The term "circuit" refers to an entirely software embodiment
or an embodiment combining software and hardware aspects, features
and/or components (including, for example, at least one processor
and software associated therewith embedded therein and/or
executable by and/or one or more Application Specific Integrated
Circuits (ASICs), for programmatically directing and/or performing
certain described actions or method steps). The circuit can reside
in one location or multiple locations, it may be integrated into
one component or may be distributed, e.g., it may reside entirely
in an MR Scanner control cabinet, partially in the MR Scanner
control cabinet, totally in a separate component or system such as
a clinician workstation but communicate with MR Scanner electronics
and/or in an interface therebetween, in a remote processor and
combinations thereof.
[0068] The term "pre-set scan plane" refers to scan planes
electronically (programmatically) defined for subsequent use by an
MRI Scanner as being associated with a location of relevant
anatomical tissue of a patient during a MRI guided therapeutic or
diagnostic procedure. The pre-set scan planes can be defined based
on a volumetric model or map of patient anatomical structure that
is subsequently registered or aligned in 3-D imaging space and can
be used to acquire near real-time MR image data of patient tissue.
The actual pre-set scan planes are typically electronically defined
after the model used to select a desired spatial location of a
corresponding relevant scan plane is registered to the 3-D imaging
space.
[0069] The term "map" is used interchangeably with the word "model"
and refers to a rendered volumetric visualization or image of
target anatomical structure of a patient. For example, a planning
map or model can take on any suitable form, including an
electrocanatomical map, MRI images, computer segmented model and
the like and combinations of same. The term "tissue
characterization map" refers to a rendered visualization or image
of one or more selected parameters, conditions, or behaviors of
cardiac tissue using MR image data, e.g., the tissue
characterization map is a rendered partial or global (volumetric)
anatomical map that shows at least one defined tissue
characteristic of the heart in a manner that illustrates relative
degrees or measures of that tissue characteristic(s), typically in
different colors, opacities and/or intensities. Notably, the tissue
characterization map is to be contrasted with an electroanatomical
tissue map which is based on sensed electrical activity of
different regions of the heart rather than on MR image data. The
planning map and/or subsequent visualizations can use one or both
types of volumetric maps. Thus, the planning map and/or
visualizations can use one or both types of volumetric tissue maps,
shown separately, overlaid on each other and/or integrated (e.g.,
superimposed) as a composite map. In some embodiments, tissue data
from an electroanatomical map and/or the tissue characteristic map
can be selectively faded or turned on and off with respect to a
pre-acquired map/model of the patient's anatomical structure (e.g.,
Left Atrium). The terms "fade" and "faded" refer to making the
so-called feature less visually dominant in a visualization (e.g.,
planning map) by dimming the intensity, color and/or opacity
relative to other features in the visualization.
[0070] The actual visualization can be shown on a screen or display
so that the map or anatomical structure is in a flat 2-D and/or in
2-D what appears to be 3-D volumetric images with data representing
features or electrical output with different visual characteristics
such as with differing intensity, opacity, color, texture and the
like, A 4-D map can either illustrate a 3-D heart with movement
(e.g., a beating heart and/or a heart with blood flow) or show
additional information over a 3-D anatomic model of the contours of
the heart or portions thereof.
[0071] The term "4-D multiparametric visualization" (4-DMP) means a
4-D visualization (e.g., a 3-D image of a beating heart) with
functional spatially encoded or correlated information shown on the
visualization. The 4-DMP visualization can be provided with fMRI
data and/or one or more tools used to provide the spatially
correlated functional data (e.g., electrical, DHE) data of the
heart based on a 3-D model. Again, the 3-D, 4-D and/or 4-DMP
visualizations are not merely an MRI image or MRI images of the
patient but are rendered visualizations that can combine multiple
sources of data to provide a visualization of spatially encoded
function with anatomical shape. Thus, the visualizations can
comprise a rendered model of the patient's target anatomy with a
rendered visualization of at least one medical device in an
intrabody location with respect to the model and along with near RT
MRI image data of the anatomical structure. The figures may include
prophetic examples of screen shots of visualizations and the like
and do not necessarily represent actual screen shots of a surgical
system/display.
[0072] The term "close-up" means that the associated image is shown
enlarged relative to a global image or map view to show local
tissue. The term "high-resolution" means that the image data is
obtained with higher resolution than normal image data (usually
requiring longer scan times and/or using an internal antenna to
increase SNR). For example, the local tissue ablation views may be
shown in higher resolution than real-time MRI images in the
navigation view. The term en face refers to a view through a tissue
wall (e.g., myocardial wall) and substantially parallel (or
tangent) to the surface.
[0073] The term "programmatically" means that the operation or step
can be directed and/or carried out by a digital signal processor,
computer program code and/or an Application Specific Integrated
Circuit (ASIC). Similarly, the term "electronically" means that the
step or operation can be carried out in an automated manner using
electronic components rather than manually or using merely mental
steps.
[0074] The term "target ablation path" describes a desired lesion
pattern that is selected to create a desired electrical isolation
in the cardiac tissue to treat the at-risk pathology/condition
(e.g., AFIB). The target ablation path is not required to be
followed in any particular direction or order. The path may include
one or more continuous and/or contiguous lesion and/or several
non-continuous or non-contiguous lesions. The lesions may be linear
(whether straight or with a curvature such as circular or
curvilinear). In any one interventional procedure, the physician
can define one or more target paths to create the desired
pattern/isolation. According to some embodiments, the target
ablation path can be used to electronically define associated
physical limits associated with the acceptable maximum boundary
limits (e.g., width, perimeter and the like) of the target ablation
path.
[0075] At least a portion of an intrabody medical device is tracked
and its position electronically identified in 3-D imaging space
(e.g., X, Y, Z coordinates). Various location tracking means for
the tool and/or registration means for the catheter to the imaging
space can be employed. For example, the intrabody device can
include fiducial markers or receive antennas combinations of same.
The term "fiducial marker" refers to a marker that can be
identified using electronic image recognition, electronic
interrogation of MRI image data, or three-dimensional electrical
signals to define a position and/or find the feature or component
in 3-D space. The fiducial marker can be provided in any suitable
manner, such as, but not limited to a geometric shape of a portion
of the tool, a component on or in the tool, a coating or
fluid-filled coating (or combinations of different types of
fiducial markers) that makes the fiducial marker(s) MRI-visible
that are active or passive (e.g., if passive, the marker does not
provide MR signal) with sufficient intensity for identifying
location and/or orientation information for the tool and/or
components thereof in 3-D space. As will be discussed further
below, in particular embodiments, the device comprises at least one
tracking coil electrically connected to a respective channel of the
MRI Scanner that generate signals that are detected (received) by
the MR Scanner and used to identify respective locations of the
coils in a 3-D coordinate system of the imaging space, and hence
the device with such tracking coils, in the 3-D image space.
[0076] The terms "MRI or MR Scanner" are used interchangeably to
refer to a Magnetic Resonance Imaging system and includes the
magnet, the operating components, e.g., RF amplifier, gradient
amplifiers and operational circuitry including, for example,
processors or ASICs (the latter of which may be held in a control
cabinet) that direct the pulse sequences, select the scan planes
and obtain MR data.
[0077] The term "RF safe" means that the catheter and any
conductive lead is configured to operate safely when exposed to RF
signals, particularly RF signals associated with MRI systems,
without inducing unplanned current that inadvertently unduly heats
local tissue or interferes with the planned therapy. The term "MRI
visible" means that the device is visible, directly or indirectly,
in an MRI image. The visibility may be indicated by the increased
SNR of the MRI signal proximate the device. The device can act as
an MRI receive antenna to collect signal from local tissue and/or
the device actually generates MRI signal itself, such as via
suitable medical grade hydro-based coatings, fluid (e.g., aqueous
fluid) filled channels or lumens. The term "MRI compatible" means
that the so-called component(s) is safe for use in an MRI
environment and as such is typically made of a non-ferromagnetic
MRI compatible material(s) suitable to reside and/or operate in a
high magnetic field environment. The term "high-magnetic field"
refers to field strengths above about 0.5 T, typically above 1.0T,
and more typically between about 1.5T and 10T. Embodiments of the
invention may be particularly suitable for 1.5T and/or 3.0T
systems.
[0078] Embodiments of the present invention can be configured to
guide and/or place diagnostic or interventional devices in an MRI
environment (e.g., interventional medical suite) to any desired
internal region of a subject of interest, including, in some
embodiments, to a cardiac location. The subject can be animal
and/or human subjects.
[0079] Some embodiments of the invention provide systems that can
be used to ablate tissue for treating cardiac arrhythmias such as
AFIB, and/or to deliver therapeutics such as stem cells or other
cardio-rebuilding cells or products into cardiac tissue, such as a
heart wall, via a minimally invasive MRI guided procedure while the
heart is beating (i.e., not requiring a non-beating heart with the
patient on a heart-lung machine).
[0080] Generally stated, advantageously, the system can be
configured so that the surgical space is the imaging space and the
tracking is performed in the imaging space so that there is no
requirement to employ a discrete tracking system that must then be
registered to the imaging space. In some embodiments, the tracking
is carried out in the same 3-D imaging space but the flexible
intrabody medical device is tracked independent of the imaging scan
planes used to obtain the MR image data for generating images of
local anatomy and is shown as a physical representation in the
visualization. The system can be configured to work with robotic
systems or non-robotic systems.
[0081] The term "near real time" refers to both low latency and
high frame rate. Latency is generally measured as the time from
when an event occurs to display of the event (total processing
time). For tracking, the frame rate can range from between about
100 fps (frames per second) to the imaging frame rate. In some
embodiments, the tracking is updated at the imaging frame rate. For
near `real-time` imaging, the frame rate is typically between about
1 fps to about 20 fps, and in some embodiments, between about 3 fps
to about 7 fps. For lesion imaging, a new image can be generated
about every 1-7 s, depending on the sequence used. The low latency
required to be considered "near real time" is generally less than
or equal to about 1 second. In some embodiments, the latency for
tracking information is about 0.01 s, and typically between about
0.25-0.5 s when interleaved with imaging data. Thus, with respect
to tracking, visualizations with the location, orientation and/or
configuration of a known intrabody device can be updated with low
latency between about 1 fps to about 100 fps. With respect to
imaging, visualizations using near real time MR image data can be
presented with a low latency, typically within between about 0.01
ms to less than about 1 second, and with a frame rate that is
typically between about 1-20 fps. Together, the system can use the
tracking signal and image signal data to dynamically present
anatomy and one or more intrabody devices in the visualization in
near real-time. In some embodiments, the tracking signal data is
obtained and the associated spatial coordinates are determined
while the MR image data is obtained and the resultant
visualization(s) with the intrabody device (e.g., flexible catheter
using the tracking coil data) and the near RT MR image(s) is
generated.
[0082] In some embodiments, MR image data is obtained during an
active treatment such as during an ablation, delivery (e.g.,
injection) of a drug or other material, valve repair or
replacement, lining repair, and the like, and the resultant
visualization(s) with the flexible intrabody device used for this
treatment (e.g., catheter, needle and the like) along with one or
more near RT MR images of local anatomy is substantially
continuously generated.
[0083] The term "intrabody device" is used broadly to refer to any
diagnostic or therapeutic medical device including, for example,
catheters, needles (e.g., injection, suture, and biopsy), forceps
(miniature), knives or other cutting members, ablation or
stimulation probes, injection or other fluid delivery cannulas,
mapping or optical probes or catheters, sheaths, guidewires,
fiberscopes, dilators, scissors, implant material delivery cannulas
or barrels, and the like, typically having a flexible body and/or
having a size that is typically between about 5 French to about 12
French, but other sizes may be appropriate. The devices may have
multiple active devices, such as multiple ablation electrodes
(typically in an array pattern), multiple needles and the like.
[0084] FIG. 1A is an example of a display 20 with a volumetric
planning model 137p of an exemplary target patient anatomical
structure (shown here as the patient's heart). The planning model
137p can be rendered using any patient-specific data in a
volumetric map 100M, including, for example, an electroanatomical
map/model, a tissue characteristic map/model or combinations of
same. The planning model 137p can comprise a global model or a
series of segmented or otherwise apportioned models of portions of
relevant anatomy (e.g., the left atrium and right atrium may be
shown separately and/or on a global planning map). The planning
model 137p can accept user input to identify, select, define or
"mark" at least one target site 55t on the planning model 137p. To
facilitate selection of a treatment site, electroanatomical and/or
tissue characteristic data can be turned "on" or "off" on the
model.
[0085] The system can allow a user to select a first target site
55t, select the pre-set associated scan plane(s) in sufficient
number to show the relevant tissue thereat, then allow a user to
select an additional site 55t and select the associated scan
plane(s), in an incremental fashion. In other embodiments, a user
may create or select a treatment pattern 55p (such as a linear
ablation pattern) and the system can identify relevant associated
scan planes to be able to image tissue associated with the target
treatment pattern 55p. The model 137p can be used to place imaging
slices on tissue having a certain spatial relationship to a feature
(e.g., tip) of a known device 80 and those imaging slices may have
certain predefined orientations for most advantageous viewing of
the tissue within.
[0086] In some embodiments, one or more points, such as a set of
points, can be virtually (automatically and/or manually) be placed
on the planning map 137p and can be used to define relevant
associated scan plane(s) 141. In some embodiments, one site 55t can
be placed or indicated on the planning map 137p by a user and the
system 10 can automatically suggest one or more planes that cover
this site 55t, and may electronically evaluate local anatomical
contour to do so. A clinician may mark fiducials to facilitate the
scan plane selection and/or the circuit may be configured to
electronically identify anatomical fiducials to identify a position
on the model and/or select suggested scan planes associated with a
target site that can be used as the actual pre-set scan plane 141
or may facilitate identification or selection of an appropriate
scan plane or maybe established as the pre-set scan plane(s)
141.
[0087] In other embodiments, a user can define the relevant scan
planes for one or more sites on the map 137p by affirmatively
indicating the desired scan plane(s) using the UI (e.g., GUI). In
some embodiments, the user can virtually mark two or more points
that can be used by the circuit to automatically define the pre-set
scan planes 141 used to obtain relevant image slices. The
automatically selected/defined pre-set scan planes 141 can be shown
visually on/through the model 137p. A user may adjust the
automatically selected scan planes 141 if desired. The UI may be
configured to allow the user to affirmatively "lock" a scan
plane(s) 141 for each selected site 55t to electronically associate
them with the planning model 137p for future use by an MR Scanner
10S.
[0088] The MRI-guided system that uses the pre-set scan planes 141
can be configured to use a slice thickness that corresponds to that
used by the MR Scanner or the scan planes 141 can be generated
using an assumed or default slice thickness and/or with a selection
of different slice thicknesses.
[0089] The target site 55t can be associated with an area of
interest such as an intersection of the left atrium and the
esophagus to allow pre-set scan planes that shown this region to
avoid damage to the esophagus during an ablation treatment of the
LA posterior wall. The target site 55t can be one or more target
treatment sites, e.g., injection or ablation sites. The target site
55t can also be associated with a target entry location, e.g., for
a septal puncture.
[0090] The system can register the scan plane locations after
registration of the model 137p to the imaging space. The system can
be configured to adjust the scan planes if the MR Scanner 10S uses
a different slice thickness or the system can direct the Scanner to
adjust its operational commands to use the slice thickness used to
set the pre-set scan planes 141. The system can be configured to
visually generate a suggested scan plane(s) 141 on the model 13'7p
that will provide a suitable image slice that covers the selected
site 55t.
[0091] In certain embodiments, the planning map 137p is used to
identify relevant target sites 55t and associated scan planes 141
(shown as one projected scan plane in FIG. 1A) in a pre-surgical
planning procedure before the actual MRI-guided surgery. The at
least one target site 55t can be selected without requiring that
the planning map 137p be registered to a 3-D (e.g., X, Y, Z)
coordinate system associated with MRI imaging space. Each site 55t
or groups of sites 55t can be electronically associated with (tied
to) one or more relevant scan planes, then registered to the 3-D
MRI imaging space for the MRI-guided procedure. For example, the
system can use the map 137p to define a plurality of different scan
planes, such as six (6) scan planes, one or more of which can be
automatically electronically associated with a respective target
site(s) 55t, such as an ablation path 55p selected in FIG. 1. In
practice, more or less scan planes may be used for a particular
path or ROI (portion) of a heart or other intrabody location. In
some embodiments, a marker, flag or identifier for the pre-set scan
planes can be tied to the identified spatial locations on the model
but the actual pre-set scan planes may not be electronically
defined until after the model is registered to the 3-D MRI imaging
space coordinate system.
[0092] Once the planning model 137p is registered to the MRI
imaging space for the MRI-guided procedure, the scan planes 141
tied to the planning model 13'7p are then electronically spatially
adjusted to the locations in the MRI 3-D imaging space. Thus, the
system 10 can be configured to import the planning map 137p,
electronically automatically or manually (via a clinician using the
display) register it to the 3-D MRI imaging space.
[0093] FIG. 1A illustrates that the UI control 25c includes a Plan
procedure (e.g., Ablation) input. This input allows a
user/physician to select one or more target sites 55t (which, in
some embodiments can be target ablation sites for forming
transmural lesions that are intended to electrically isolate one or
more regions of interest of cardiac tissue). Where used, the target
path 55p can be one continuous path or several discontinuous paths
in a region of interest (ROI). The Plan Procedure input/mode may be
particularly suitable for implementation or use during a
pre-procedure planning stage of an interventional procedure or at
an evaluation stage prior to conclusion of a procedure. The map
137p can be or is subsequently registered to 3-D coordinate
space.
[0094] The system 10 (FIGS. 3-5), e.g., a circuit 60c associated
with the MRI Scanner 10S (FIG. 5) can electronically suggest
relevant pre-set scan planes 141 that generate image slices that
cover the at least one target site 55t. The system 10 can
automatically use the pre-set scan plane 141 during a surgical
procedure when a known intrabody device 80 is in proximity to a
defined corresponding target site 55t.
[0095] In other embodiments, the planning map 137p is registered to
the 3-D MRI imaging space prior to selection or identification of
the at least one target site 55t and/or pattern 55p and the scan
planes 141 are then automatically correctly associated with the
imaging space and the MRI scanner 10S.
[0096] In certain embodiments, during the MRI-guided procedure, the
system 10 (e.g., circuit 60c) can interact with the intrabody
device 80 to select a relevant pre-set scan plane 141 (coronal,
sagittal, transverse) corresponding to a tracked location of a
distal end portion of the intrabody device. In some embodiments,
the pre-set scan plane(s) 141 used during the MRI-guided procedure
is selected based on defined projected distance at and/or beyond a
distal tip of the intrabody device 80 (axial and/or perpendicular
to the distal end portion of the device or substantially parallel
to tissue thereat) in near real time during an MRI-guided surgical
procedure.
[0097] In certain embodiments, the system 10 (typically circuit
60c) (FIGS. 3-5) can be configured so that the display 20 provides
a list or selection of different surgical procedures that treat
different defined conditions and they may be grouped by treatment
type. For example, a set of options for cardiac EP systems,
including, for example, Procedure A to treat chronic atrial
fibrillation, Procedure B to treat flutter, Procedure C to perform
a clinician stored protocol that automatically displays a preferred
treatment site pattern (e.g., a linear ablation for AFIB). A user
can select Procedure A, for example, and this action can cause the
system/circuit to generate a suggested target ablation pattern 55p
in the planning image/model 137p that is conventional for this
condition. The ablation pattern 55p can be morphed to conform to
patient contour using anatomical landmarks or features, such as for
certain cardiac procedures, the pulmonary veins. Examples of
selectable treatment plans with associated (different suggested
ablation sites/patterns are listed below).
TABLE-US-00001 Arrythmia Condition Suggested Ablation Sites AFIB
Procedure A pattern Right Atrial Flutter Procedure B pattern AVNRT
(atrial ventricular Procedure C pattern nodal re-entry tachycardia)
Atrial tachycardia Procedure D pattern WPW (Wolff Parkinson White
syndrome Procedure E pattern Left Atrial Flutter Procedure F
pattern Right Ventricular Tachycardia Procedure G pattern Left
Ventricular Tachycardia Procedure H pattern
[0098] A user/clinician can select the proposed or suggested
pattern 55p and/or adjust the pattern on the map 137p by adding,
moving or removing portions of the default ablation sites 55t shown
on the planning image 137p. For example, if a user selects
Procedure A, a suggested default ablation pattern can be shown on
the planning map 137p with the clinical goal to provide electrical
isolation of the pulmonary veins and a posterior wall of the left
atrium.
[0099] Thus, in some embodiments, a user can select a relevant
"procedure" from a pre-defined list such as a pull-down menu or
other user interface (UI), typically a GUI (graphical user
interface) for a patient which can allow a user to cause the system
to display a corresponding suggested treatment (e.g., ablation)
pattern. If satisfactory (which can be affirmatively indicated by a
clinician), the system can then electronically evaluate patient
structure (contour) and generate suggested scan planes that provide
image slices that cover relevant anatomical locations. The
system/circuit can suggest a minimum number of scan planes 141 that
cover the patient geometry in the at least one target site 55t.
[0100] In some embodiments, the system/circuit can be configured to
generate a grid or template 55g (FIG. 1B) that can be applied to
the map 137p of the patient's anatomy and that can provide the
suggested treatment pattern 55p. The grid or template 55g can be
electronically adjustable by a user to more closely fit patient
anatomical contour. The grid or template 55g may also be configured
to identify specific regions (such as sensitive areas)
automatically or using clinician input. Similar to the "Procedure"
guide described above, the template or grid can be electronically
applied to the planning map 137p to illustrate suggested treatment
sites based on defined criteria that identifies likely relevant
treatment sites or spots associated with a particular condition and
may also consider patient tissue data, anatomical structure,
vasculature, fibrous tissue, wall thickness, electrical activity,
and the like.
[0101] The UI control 25c that can be configured to allow a
physician or other clinician to select a region of interest in the
map 137p by placing a mark, cursor, pen, or by touching the screen
at a region of interest. This can cause the system to define a
target site 55t and electronically define preset scan planes for
use during an interventional procedure. The circuit 60c can use the
map 137p to define one or a plurality of different scan planes,
such as between one (1)-six (6) scan planes. In practice, more or
less scan planes may be used for a particular path or ROI (portion)
of a heart. Any scan plane can be temporarily disabled to allow
faster update of the remaining scan planes.
[0102] FIGS. 2A and 2B illustrate a display 20 with a visualization
100v that includes the planning map 137p registered to the imaging
space along with MRI image data 100MRI obtained by an MR Scanner
10S while a patient is in the MR Scanner 10S typically just prior
to or at the start of the MRI-guided interventional procedure. The
system can be configured to allow a user to "turn on" (FIG. 2B)
and/or "off" (FIG. 2A) or fade the rendered planning map 137p
and/or the target sites 55t or use a different volumetric map (both
generally referred to using feature 100M) of the patient in the
visualization 100v during the MRI-guided procedure. The planning
map 137p can be imported and electronically interrogated to define
the pre-set scan planes 141 adjusted to reflect the model
registered to the 3-D imaging space. This action can be "in the
background". The display 20 can include a UI 25c that allows a user
to select whether to show the planning map 137p on the display
(typically as part of the visualization 100v) and/or to cause the
system to identify and correlate the pre-set scan planes for use
during the MRI-guided procedure.
[0103] FIG. 3 illustrates an MRI interventional system 10 with a
scanner 10S and a (typically flexible) intrabody medical device 80
proximate target tissue 100 at a device-tissue interface 100i. The
system 10 can be configured to electronically track the 3-D
location of the device 80 in the body and identify and/or "know"
the location of the tip portion of the device 80t (e.g., the
ablation or needle tip) in a coordinate system associated with the
3-D MRI imaging space.
[0104] As shown in FIG. 5, the display 20 can be provided in or
associated with a clinician workstation 60 in communication with an
MRI Scanner 10S. The MRI Scanner 10S typically includes a magnet 15
in a shielded room and a control cabinet 11 (and other components)
in a control room in communication with electronics in the magnet
room. The MRI Scanner 10S can be any MRI Scanner as is well known
to those of skill in the art. Examples of current commercial
scanners include: GE Healthcare: Signa 1.5T/3.0T; Philips Medical
Systems: Achieva 1.5T/3.0T; Integra 1.5T; Siemens: MAGNETOM Avanto;
MAGNETOM Espree; MAGNETOM Symphony; MAGNETOM Trio.
[0105] The workstation 60 can include the circuit 60c (e.g., ASIC
and/or processor with software) that includes or executes part or
all of the computer readable program code for generating the
pre-set scan planes and/or identifying the pre-set scan planes.
However, part or all of the circuit 60c can reside in the MRI
Scanner 105, the interface 44 (where used) and/or in one more
remote processors.
[0106] Optionally, an MRI scanner interface 44 may be used to allow
communication between the workstation 60 and the scanner 105. The
interface 44 may reside partially or totally in the scanner 10S,
partially or totally in the workstation 60, or partially or totally
in a discrete device (shown in broken line in FIG. 5). The display
20 can be configured to render or generate near real time
visualizations 100v of the target anatomical space using MRI image
data and can illustrate at least one intrabody device 80 in the
space. As is known, the at least one intrabody device 80 can
comprise an ablation catheter that can include one or more tracking
coils, an ablation electrode, passive markers and/or a receive
antenna (or combinations of the above).
[0107] As shown in FIG. 3, the device 80 can include a plurality of
spaced apart tracking members 82 on a distal end portion thereof.
In a particular embodiment, the device 80 can be an ablation
catheter and the distal end portion 80d, typically tip 80t, can
include an electrode 80e (typically at least one at a distal end
portion of the device). Where used, the electrode can be either or
both a sensing and ablation electrode.
[0108] The tracking members 82 can comprise miniature tracking
coils, passive markers and/or a receive antenna. In a preferred
embodiment, the tracking members 82 include at least one miniature
tracking coil 82c that is connected to a channel 10ch of an MRI
Scanner 10S (FIGS. 4, 5). The MR Scanner 10S can be configured to
operate to interleave the data acquisition of the tracking coils
with the image data acquisition. The tracking data is typically
acquired in a `tracking sequence block` which takes about 10 msec
(or less). In some embodiments, the tracking sequence block can be
executed between each acquisition of image data (the latter can be
referred to as an `imaging sequence block`). So the tracking coil
coordinates can be updated immediately before each image
acquisition and at the same rate. The tracking sequence can give
the coordinates of all tracking coils simultaneously. So,
typically, the number of coils used to track a device has
substantially no impact on the time required to track them.
[0109] Embodiments of the present invention provide a new platform
that can help facilitate clinical decisions during an MRI-guided
procedure and can present real anatomical image data to the
clinician in a visualization 100v. The visualizations 100v (FIGS.
7A-7D) can be dynamically generated as the intrabody device 80
moves in the body into a target location, as a user rotates, crops
or otherwise alters a displayed visualization or view and/or during
an active therapy or diagnostic procedure step, e.g., while
ablating at target lesion sites, with minimal latent time between
serial MRI image data acquisitions, typically less than about 5
seconds, typically substantially continuously with a minimal latent
time of about 1 second or less, such as between about 0.001 seconds
and 1 second. Together, the system 10 can use the tracking
signal(s) and image signal data to dynamically track the device 80
(which is typically a plurality of devices) and present
visualizations of the anatomy and one or more intrabody devices 80
in near real-time without requiring the device to be in the MRI
image scan planes.
[0110] The term "physical representation" means that a device is
not actually imaged but rather rendered with a physical form in the
visualizations, typically with a three-dimensional shape or form.
Typically, the physical representation is a partial physical
representation which shows the distal end portion of the device in
the body in the 3-D MR image space. The physical representation may
be of any form including, for example, a graphic with at least one
geometric shapes, icons and/or symbols. In some particular
embodiments, the physical representation may be a virtual graphic
substantial replica substantially corresponding to an actual shape
and configuration of the actual physical appearance and/or
configuration of the associated device (see, e.g., FIGS. 9, 10,
12). The physical representation can be electronically generated
based on a prior knowledge of the dimensions and configuration of
the device. The tip and each tracking coil on a distal end of a
particular device may be shown in a geometric shape (the same or
different shapes, e.g., an arrow for the tip and a sphere or block
or other (typically 3-D) shape for tracking coils, each in its real
location in the 3-D space and in its relative position on the
device and each may be rendered with the same or a different color.
For example, the distal tip and each proximate tracking coil may be
shown in a different color. The rendered distal end portion of the
device is typically shown to look substantially the same as the
physical device.
[0111] The term "tortuous" refers to a curvilinear pathway in the
body, typically associated with a natural lumen such as
vasculature. The term "dynamic visualizations" refers to a series
of visualizations that show the movement of the device(s) in the
body and can show a beating heart or movement based on respiratory
cycle and the like.
[0112] The term "pre-acquired" means that the data used to generate
the model or map of the actual patient anatomy can be obtained
prior to the start of an active therapeutic or diagnostic procedure
and can include immediately prior to but during the same MRI
session or at an earlier time than the procedure (typically days or
weeks before).
[0113] Embodiments of the present invention can be configured to
guide and/or place intrabody diagnostic and/or interventional
devices in an MRI environment (e.g., interventional medical suite)
to any desired internal region of interest of a subject, typically
via a natural lumen and/or tortuous path so that the intrabody
devices can take on different non-linear configurations/shapes as
it moves into position through a target pathway (which may be a
natural lumen or cavity). The subjects can be animal and/or human
subjects.
[0114] Some embodiments of the invention provide systems that can
be used to ablate tissue for treating arrythmias such as AFIB, to
repair or replace cardiac valves, repair, flush or clean
vasculature and/or place stents, and/or to deliver stem cells or
other cardio-rebuilding cells or products into cardiac tissue, such
as a heart wall, via a minimally invasive MRI guided procedure
while the heart is beating (i.e., not requiring a non-beating heart
with the patient on a heart-lung machine). The cardiac procedures
can be carried out from an inside of the heart or from an outside
of the heart. Thus, some embodiments are directed to cardiac
procedures for treating cardiac arrythmias or heart failure (e.g.,
congestive heart failure, reduced heart function, and the
like).
[0115] Thus, the map 137p for cardiac procedures can be an
electroanatomical map, a tissue characterization map, or
combinations of shame of at least a portion of the patient's heart.
Typically the map is rendered to represent portions or regions of
the heart, such as the left atrium and any adjacent vasculature of
interest (e.g., the branching of the pulmonary veins), the
ventricles and the like.
[0116] Other embodiments provide systems suitable for delivering a
therapeutic agent or carrying out another treatment or diagnostic
evaluation for any intrabody location, including, for example, the
brain, gastrointestinal system, genourinary system, spine (central
canal, the subarachnoid space or other region), vasculature or
other intrabody locations. Additional discussion of exemplary
target regions can be found at the end of this document. To be
clear, while detailed drawings of exemplary flexible devices 80 are
shown for tracking coils for transseptal needles (septal puncture
kit components) and mapping and/or ablation catheters for cardiac
use, embodiments of the invention are not intended to be limited to
these devices nor to cardiac use. Exemplary devices are listed
above. Exemplary (non-cardiac) intrabody locations are listed at
the end of this document. For example, the device can be
implemented as injection catheters or diagnostic biopsy needles and
the like for any target anatomical location in the body. See, e.g.,
U.S. patent application Ser. No. 10/769,994 (intramyocardial
injection needle), U.S. Pat. No. 7,236,816 (biopsy needle), and
U.S. Pat. No. 6,606,513 (transseptal needle), the contents of which
are hereby incorporated by reference as if recited in full
herein.
[0117] The system 10 and/or circuit 60c can calculate the position
of the tip of the device 80t as well as the shape and orientation
of the flexible device based on a priori information on the
dimensions and behavior of the device 80 (e.g., for a steerable
device, the amount of curvature expected when a certain pull wire
extension or retraction exists, distance to tip from different
coils 82 and the like). Using the known information of the device
80 and the tracking signals (which are spatially associated with
the same X, Y, Z coordinate system as the MR image data) the
circuit 60c can select a scan plane(s) from one of the pre-set scan
planes 141 that is most closely correlated to the location of the
distal end of the device to rapidly generate visualizations showing
a physical representation of the location of a distal end portion
of the device 80 with near RT MR images of the anatomy.
[0118] In some embodiments, the tracking signal data is obtained
and the associated spatial coordinates are determined while a
circuit 60c in the MRI Scanner 10S (FIG. 4) and/or in communication
with the Scanner 10S (FIG. 5) obtains MR image data. The reverse
operation can also be used. The circuit 60c can then rapidly render
the resultant visualization(s) 100v (see, e.g., FIGS. 7A-71D) with
the device(s) 80 shown with a physical representation based on
spatial coordinates of the devices in the 3-D imaging space
identified using the associated tracking coil data and the near RT
MR image(s).
[0119] FIG. 4 illustrates that the device 80 can include at least
one conductor 81, such as a coaxial cable that connects a
respective tracking coil 82c to a channel 10ch of the MR Scanner
10S. The MR Scanner 10S can include at least 16 separate channels,
and typically more channels but may operate with less as well. Each
device 80 can include between about 1-10 tracking coils, typically
between about 2-6. The coils 82c on a particular device 80 can be
arranged with different numbers of turns, different dimensional
spacing between adjacent coils 82c (where more than one coil is
used) and/or other configurations. The circuit 60c can be
configured to generate the device renderings based on tracking coil
locations/positions relative to one another on a known device with
a known shape and/or geometry or predictable or known changeable
(deflectable) shape or form (e.g., deflectable end portion). The
circuit can identify or calculate the actual shape and orientation
of the device for the renderings based on data from a CAD (computer
aided design) model of the physical device. The circuit can include
data regarding known or predictable shape behavior based on forces
applied to the device by the body or by internal or external
components and/or based on the positions of the different tracking
coils in 3-D image space and known relative (dimensional)
spacings.
[0120] The tracking coils 82c can each include a tuning circuit
that can help stabilize the tracking signal for faster system
identification of spatial coordinates. FIG. 6 illustrates an
example of a tuning circuit 83 that may be particularly suitable
for a tracking coil 82c on a catheter. As shown, CON1 connects the
coaxial cable to the tracking coil 82c on a distal end portion of
the device 80 while J1 connects to the MR Scanner channel 10ch. The
Scanner 10S sends a DC bias to the circuit 83 and turns U1 diode
"ON" to create an electrical short which creates a high impedance
(open circuit) on the tracking coil to prevent current flow on the
tracking coil and/or better tracking signal (stability). The tuning
circuit can be configured to have a 50 Ohm matching circuit (narrow
band to Scanner frequency) to electrically connect the cable to the
respective MR Scanner channel. When the diode U1 is open, the
tracking coil data can be transmitted to the MR Scanner receiver
channel 10ch, The C1 and C2 capacitors are large DC blocking
capacitors. C4 is optional but can allow for fine tuning (typically
between about 2-12 picofarads) to account for variability
(tolerance) in components. It is contemplated that other tuning
circuits and/or tracking signal stabilizer configurations can be
used. The tuning circuit 83 can reside in the intrabody device 80
(such as in a handle or external portion), in a connector that
connects the coil 82c to the respective MRI scanner channel 10ch,
in the Scanner 10S, in an interface box 86 (FIG. 2), a patch panel
250 and/or the circuit 83 can be distributed among two or more of
these or other components.
[0121] In some embodiments, each tracking coil 82c can be connected
to a coaxial cable 81 having a length to the diode via a proximal
circuit board (which can hold the tuning circuit and/or a
decoupling/matching circuit) sufficient to define a defined odd
harmonic/multiple of a quarter wavelength at the operational
frequency of the MRI Scanner 10S, e.g., .lamda./4, 3.lamda./4,
5.lamda./4, 7.lamda./4 at about 123.3 MHz for a 3.0T MRI Scanner.
This length may also help stabilize the tracking signal for more
precise and speedy localization. The tuned RF coils can provide
stable tracking signals for precise localization, typically within
about 1 mm or less. Where a plurality (e.g., two closely spaced)
adjacent tracking coils are fixed on a substantially rigid
material, the tuned RF tracking coils 82 can provide a
substantially constant spatial difference with respect to the
corresponding tracking position signals.
[0122] The tracking sequence used in the system 10 can
intentionally dephase signal perpendicular to the read-out
direction to attenuate unwanted signal from 1) bulk objects and 2)
regions sensed by other signal sensitive parts of the catheter
which couple to the tracking coil (e.g. the coaxial cable along the
catheter shaft). This tends to leave only a sharp peak indicating
the position of the tracking coil.
[0123] The tracking sequence block can include or consist of a
plurality of (typically about three) repetitions of a small
flip-angle excitation. Each repetition is designed to indicate the
x, y or z component of the tracking coil coordinates in succession.
Frequency encoding is used along the x-direction to obtain the
x-coordinate, the y-direction for the y-coordinate, and the
z-direction for the z-coordinate. When the frequency encoding is in
the x-direction, the other two directions (y and z) are not
spatially encoded, producing projection (spatially integrated)
signals in those directions from all excitation regions. The
dephasing gradient attempts to attentuate unwanted signal included
in these projections. Once the tracking sequence block is complete,
a spoiler gradient can be used to dephase any transverse signal
remaining from the tracking before the imaging sequence block is
executed.
[0124] The imaging sequence block obtains a portion, depending on
the acceleration rate, of the data used to reconstruct an image of
a single slice. If the acceleration rate is 1, then all of the data
for an image is collected. If the acceleration rate is 2, then half
is collected, etc. If multiple slices are activated, then each
successive imaging block collects data for the next slice, in
`round robin` fashion. If any magnetization preparation (e.g.,
saturation pulses) are activated, these are executed after the
tracking sequence block, immediately before the imaging sequence
block.
[0125] Additional discussion of tracking means and ablation
catheters can be found in U.S. Pat. No. 6,701,176, and U.S.
Provisional Application Ser. No. 61/261,103, the contents of which
are hereby incorporated by reference as if recited in full herein.
Exemplary ablation catheters will be discussed further below.
[0126] Referring now to FIGS. 7A-7D and 8, examples of
visualizations 100v that may be rendered with a physical
representation 80R of the intrabody device 80, a volumetric model
100M of target anatomical structure and a near real-time MRI image
100MRI. As noted above, the model 100M can comprise the planning
model 137p. The circuit 60c/Scanner 10S is configured to present a
3-D volumetric model of at least a portion of the patient's target
anatomy (shown as the heart) 100M in the visualization 100v with
the model registered to the 3-D imaging space along with a physical
representation of at least the distal end portion of the at least
one intrabody device 80R in the imaging space.
[0127] The circuit 60c can be configured to generate the
visualizations 100v with at least two visual reference planes 41,
42 (shown with a third intersecting plane 43) that are oblique or
orthogonal to each other and extend through at least a major
portion of the visualization 100v. The planes 41, 42 (and 43) can
be transparent and/or translucent. They may be shown with different
color perimeters that correspond to a respective two-dimensional
image slice (which may be shown as thumbnails on the display also
with a perimeter of similar or the same color).
[0128] The planes 41, 42 can move relative to each other in the
imaging space or may be locked together, in any case they can be
configured to move relative to the model 100M in the imaging space.
As shown in FIGS. 7A-7D, a user can rotate and zoom the
visualization 100v which automatically adjusts the visualization
shown on the display. As also shown, the flexible device 80 is not
required to be in any of the relevant anatomical scan planes used
to obtain MR data for the at least one near RT MRI image 100MRI in
the visualization and the distal end portion 80d of the flexible
device 80 can take on a curvilinear shape and the tip 80t can be
steered or guided into different target positions.
[0129] In some embodiments, as shown in FIG. 7D, the circuit 60c is
configured to associate a tip location of the at least one device
80 with an arrow 82a and render the visualization so that each
tracking coil 82 on the distal end portion 80d has a shape 82s with
a color, with each tracking coil 82 having a respective different
color from the other tracking coils, and with a line or spline
82/connecting the tip 82a and the coils 82c and the line 82/is able
to flex, bend and move to reflect movement of the device 80 in the
visualizations 100v. It is contemplated that the visualizations
100v will be carried out so that the device 80R is rendered
visually similar to the actual device. The spline can be used to
programmatically help render the physical appearance and
orientation (and may not be shown in the visualization itself).
[0130] FIG. 8 illustrates that the system 10 can be configured to
show both the interactive visualization 100v in one viewing window
20w.sub.1 and an MRI image 100MRI alone in a second viewing window
20w.sub.2. The MRI image 100MRI in the second window 20w.sub.2 is
typically associated with the target anatomy location identified by
a user in the interactive visualization 100v in the first viewing
window 20w.sub.1.
[0131] As shown in FIG. 9, the display 20 can have a UI 25 with at
least one UI control 25c that can be configured to allow a
physician or other clinician to select whether to show near real
time MR images of target tissue 100MRI either with a model 100M of
the target anatomical structure and/or in a separate viewing
window. The circuit 60 is in communication with at least one
display 20 with the User Interface 25. The User Interface control
25c can be configured to allow a user to alter the displayed
visualization (fade) to include only a near RT image of the
anatomy, to include the near RT image of the anatomy and the
registered model of the heart, or to include only the registered
model. The UI 25 can be an on off selection of these options or may
"fade" from one viewing option to another. As shown, a virtual
sliding control 25c allows a user to change what is shown ((near)
RTMRI 100MRI to only the Model 100M).
[0132] The UI 25 typically includes multiple GUI controls that can
include a touch screen input control to allow a clinician/physician
to select a region of interest in the map 100M by placing a cursor
or by touching the screen at a region of interest. This can cause
the system to obtain real time MR image data of that region and
provide the associated image on the display and/or define scan
planes (which may be preset scan planes 141) at that location in
space.
[0133] Referring again to FIG. 2A, for example, the display can
present a UI 25 that allow a user to select to show data from one
or more different maps 30 with at least some of the maps being
tissue characterization maps, so that the map or data therefrom can
be "turned on and off" on the displayed 3-D anatomical map
registered to the imaging space. For tissue characterization maps,
the maps include spatially correlated tissue characterization data
taken from MR image data incorporated therein as discussed above.
The UI 25 can include multiple different GUI (Graphic User Input)
controls 25c for different functions and/or actions. The GUI
controls 25c may also be a toggle, a touch screen with direction
sensitivity to pull in one direction or other graphic or physical
inputs.
[0134] The UI 25 can be configured to allow a user to zoom, crop,
rotate, or select views of the displayed map 30 (also
interchangeably identified as 100M herein). As shown, one GUI
control 25c can be a slide control 50, on a lower portion of the
display 20 that can allow a user to select whether to display
RT-MRI (Real Time MRI images) 51 or a tissue characterization map
30, or combinations thereof (e.g., the slide can allow a fade-away
display between the two types of images). The GUI control 50 may
also be a toggle, a touch screen with direction sensitivity to pull
in one direction or other graphic or physical inputs.
[0135] The circuit 60c can also be configured to generate MRI
images which show the device location in near real time (in the MR
image space). The UI 25 can also be configured to allow a user to
turn off and/or fade the renderings of the device 80 in and out of
the visualizations with rendered views of the device versus actual
images of the device to confirm location or for additional visual
input. The device may include other fiducial markers (e.g., a
passive marker or an active marker such as receive antenna) for
facilitating the visual recognition in the MR image.
[0136] The UI 25 can include a list of user selectable
patient-specific images and/or maps 30 including a plurality of
tissue maps, typically including at least one, and more typically,
several types of, tissue characterization maps (or data associated
with such maps) associated with the procedure that can be selected
for viewing by a user. The UI 25 can also include GUI controls that
allow a user to select two or more of the tissue characteristic
maps, with such data able to be shown together (overlaid and
registered and/or as a composite image) or separately. As shown,
the maps 30 may include at least a plurality of the following:
[0137] (a) a regional evaluation tissue characterization map 32
which shows actual lesion patterns in one region to allow a
clinician to view regional (ablation) information (such as at the
LA (left atrium), a PV (pulmonary vein) and the like) and/or a
global evaluation tissue characterization map 32;
[0138] (b) pre-procedure MRI cardiac scans 34;
[0139] (c) DHE 1 (Delayed Hyper Enhancement) tissue
characterization map 35a taken at a first point in time (such as a
week or just prior to the procedure);
[0140] (d) DHE 2 tissue characterization map 35b taken at a second
point in time, such as during a procedure, potentially toward an
end of the procedure to confirm complete electrical isolation of
the PV (pulmonary veins) or other targets prior to terminating the
procedure--alternatively the DHE 2 map can be associated with the
end of a prior EP ablation procedure;
[0141] (e) an EA (electroanatomical) map 35c;
[0142] (f) an edema tissue characterization map 35d;
[0143] (g) other tissue characterization maps, for example: [0144]
(i) a composite thermal tissue characterization map that shows
positions of increased temperature that were caused by ablation of
tissue during the procedure; [0145] (ii) ischemic (oxygen deprived
or lacking) tissue characterization map; [0146] (iii) hypoxic or
necrotic tissue characterization map; [0147] (iv) fibrous tissue
map; [0148] (v) vasculature map; [0149] (vi) cancer cell/tissue map
(where cancer is the condition being treated); [0150] (vii) a fluid
distribution map (for visualizing injected or otherwise delivered
therapeutic fluid in local tissue of the target anatomical
structure); [0151] (viii) light exposure maps; and
[0152] (h) at least one procedure planning map 137P with target
sites 55t (FIG. 10) and a later tissue map showing target 55t and
actual treatment sites 55a (e.g., target and actual ablation sites)
shown in different colors, opacities and/or intensities for ease of
reference (see, e.g., FIG. 9, darker spots represent target sites
and lighter spots represent actual sites); and
[0153] (i) device views 36 that show the physical representation of
the device 80R in the surgical/imaging space, e.g., with an
ablation catheter 36a shown in position and/or a mapping (loop)
catheter 36b as devices 80R shown in position (FIGS. 9, 10). These
device maps 36 may be used/displayed, for example, during a
navigation mode. The default action may be to show these devices at
least in the navigation mode but a user can deselect this choice.
The devices may also be "turned" off or faded or shown in wire grid
or otherwise in the visualizations subject typically to user
input.
[0154] The display UI 25 can be configured to allow a physician or
other clinician to select whether to show real time MR images of
target tissue either in the tissue map and/or in a separate view or
window. The UI 25 typically includes multiple GUI controls that can
include a touch screen input control to allow a clinician/physician
to select a region of interest in the tissue characterization map
by placing a cursor or by touching the screen at a region of
interest. This can cause the system to obtain near real time MR
image data of that region and provide the associated image on the
display and/or use preset scan planes associated with that location
in the imaging space.
[0155] Pre-acquired tissue characterization maps 30 are typically
registered to 3-D coordinate space so that the relevant scan planes
used to obtain MR image data obtained from the patient during a
procedure can be pre-set as discussed above. Data associated with
one or more of the tissue characterization maps can be updated over
time (including in near real time) using MR image data
automatically or upon request by a user. The tissue maps can also
be obtained during the procedure so that the MR image data is in
the 3-D MRI image space. EA maps can be imported or generated using
tracking and/or mapping catheters in the 3-D MRI image space, the
latter of which may provide a more accurate or timely EA map
(without requiring registration of a pre-acquired map).
[0156] The tissue characteristic map(s) 30 can be generated using
MR image data that shows normal and abnormal status, conditions
and/or behavior of tissue (such as in response to a therapeutic
treatment). For example, the tissue characterization map(s) 30 can
show a thermal profile in different colors (or gray scale) of
cardiac tissue in a region of interest and/or globally. In other
embodiments, the tissue characterization map 30 can illustrate one
or more of infarcted, injured, necrotic, hypoxic, ischemic,
scarred, edemic (e.g., having edema) and/or fibrotic tissue or
otherwise impaired, degraded or abnormal tissue as well as normal
tissue on an anatomical model of the heart. In yet other
embodiments, the tissue characterization map can illustrate
portions of the heart (e.g., LA or posterior wall) with lesser or
greater wall motion, and the like.
[0157] In some embodiments, the system can be used to deliver a
therapeutic to target anatomy using an injection needle or fluid
delivery cannula. A fluid distribution map or data therefrom can be
shown on the model 100M or in the MRI image 100MRI (without
requiring the rendered model). For example, to treat heart failure,
a therapeutic agent can be injected into one or more target
locations in infarct or abnormal cardiac tissue. Typically, the
injection is carried out in several spots to generate a desired
coverage pattern or area/volume. The fluid distribution map can be
used to confirm that desired coverage of the cardiac tissue was
obtained based on the injections. If not, another ("clean-up")
target site or sites can be identified and the sites can be
injected with the therapeutic agent. In other embodiments, a
previous injection site may need additional volumes of the agent,
so that same site can be treated again. The fluid distribution map
can be generated based on MRI image data alone. In other
embodiments, a fluid distribution map can be generated based on a
known injection site or sites, and a known volume of injected agent
(which may be measured in situ or based on a known flow rate and
known time of injection). This data can be used to generate an
estimated fluid distribution map. In other embodiments, a fluid
distribution map can be generated based on both MR image data and
injection amounts. In some embodiments, the system/circuit 60c can
indentify a spatial grouping of injection sites and electronically
select a scan plane or scan planes that can be set through the
injection sites to obtain near RT MRI image data or obtain image
data after the injections (such as for a regional or global
coverage evaluation prior to the end of the MRI-guided procedure).
For cardiac injections for some heart repairs, a planning map 37M
identifying infarct tissue and normal (healthy) tissue boundaries
can be used to identify target injection sites 55t. This map 37M
can be registered to the MRI image space. A target site 55t can be
associated with the X, Y, Z location in the MRI image space. Near
RT images 100MRI can be generated during the injections (similar to
the ablations) to allow a physician to see "live" the injection
distribution or disbursement. This fluid distribution map can be
electronically provided as a data set that can be selectively shown
on the anatomical model 100M. The therapeutic agent can be any
suitable agent including, for example, stem cells (and may be
directed to rebuilding cardiac tissue) and is MRI visible.
[0158] Other embodiments can generate light exposure maps to
evaluate optical light exposure of target tissue (or light
activated drugs in such tissue) similar to the fluid distribution
map discussed above. The light exposure map can be based on an
internal laser or other light source that exposes the tissue to
non-ablative energy.
[0159] Whether a parameter or tissue characteristic is shown in the
tissue characteristic map as being impaired, degraded or otherwise
abnormal or affected by a treatment versus normal or untreated can
be based on the intensity of pixels of the tissue characteristic in
the patient itself or based on predefined values associated with a
population "norm" of typical normal and/or abnormal values, or
combinations of the above.
[0160] Thus, for example, normal wall motion can be identified
based on a comparison to defined population norms and different
deviations from that normal wall motion can be shown as severe,
moderate or minimal in different colors relative to tissue with
normal wall motion.
[0161] In another example, a thermal tissue characterization map
can illustrate tissue having increased temperatures relative to
other adjacent or non-adjacent tissue. Thus, for example, during or
shortly after ablation, the lesioned tissue and tissue proximate
thereto can have increased temperatures relative to the
non-lesioned temperature or tissue at normal body temperatures.
Areas or volumes with increased intensity and/or intensity levels
above a defined level can be identified as tissue that has been
ablated. The different ablation sites 55t can be shown on the map
30 as areas with increased temperatures (obtained at different
times during the procedure) and incorporated into the thermal
tissue characterization map 30 automatically and/or shown upon
request.
[0162] In some embodiments, the tissue characteristic map 30 uses
MR image data acquired in association with the uptake and retention
of a (e.g., T-1 shortening) contrast agent. Typically, a longer
retention in tissue is associated with unhealthy tissue (such as
infarct tissue, necrotic tissue, scarred tissue and the like) and
is visually detectable by a difference in image intensity in the MR
image data, e.g., e.g. using a T1 weighted sequence, to show the
difference in retention of one or more contrast agents. This is
referred to as delayed enhancement (DE), delayed hyper-enhancement
(DHE) or late gadolinium enhancement (LGE).
[0163] The map 100M is typically a volumetric, 3-D or 4-D
anatomical map that illustrates or shows tissue characterization
properties associated with the volume. The map can be in color and
color-coded to provide an easy to understand map or image with
different tissue characteristics shown in different colors and/or
with different degrees of a particular characterization shown in
gray scale or color coded. The term "color-coded" means that
certain features or conditions are shown with colors of different
color, hue or opacity and/or intensity to visually accentuate
different conditions or status of tissue or different and similar
tissue, such as, for example, to show lesions in tissue versus
normal or non-lesion tissue or injected fluid locations and
coverage/distribution.
[0164] In some embodiments, the UI 25 can be configured to allow a
clinician to increase or decrease the intensity or change a color
of certain tissue characterization types, e.g., to show lesion
tissue or tissue having edema with a different viewing parameter,
e.g., in high-contrast color and/or intensity, darker opacity or
the like. A lesion site(s) in the tissue characteristic map 30 can
be defined based on an ablation position in three-dimensional space
(e.g., where an electrode is located based on location detectors,
such as tracking coils, when the ablation electrode is activated to
ablate), but is typically also or alternately associated with MRI
image data in associated scan planes to show an ablation site(s) in
an MRI image. The MR image data may also reflect a change in a
tissue property after or during ablation during the procedure,
e.g., DHE, thermal, edema and the like.
[0165] The circuit can be configured to generate a difference or a
comparison map that is generated from a pre-procedure or start-of
procedure tissue characterization map and an intra-procedure tissue
characteristic map to show the differences based on the procedure.
The "before" and "after" maps can be electronically overlaid on a
display and shown in different colors, opacities and/or intensities
or corresponding pixel values from each image in a ROI can be
subtracted to show a difference map. Again, the UI 25 can allow a
clinician to select or deselect (or toggle between) the before or
after tissue characterization maps or adjust display preferences to
allow a visual review of differences.
[0166] A regional update tissue characterization map 32 can be used
to evaluate whether ablated locations have the desired lesion
formation. The UI 25 can allow the clinician to request a high
resolution or enlarged view of the actual ablated tissue merely by
indicating on the regional evaluation tissue characterization map a
desired region of interest (e.g., by pointing a finger, cursor or
otherwise selecting a spot on the display). For example, a high
resolution MR image of suspect tissue in the LSPV can be shown so
that the physician can see actual tissue in the desired spot
indicated on the tissue characterization map. New targets can be
marked on the map as needed and again, pre-set scan planes can be
automatically associated with the new targets by location.
[0167] The MRI Scanner 10 can be operated substantially
continuously to provide image data that can be used to generate
updated tissue characteristic maps upon request or automatically.
This operation can be "in the background", e.g., transparent to the
user so as not to slow down the procedure while providing updated
image data during the course of the procedure.
[0168] FIGS. 9 and 10 show target ablation sites 55t on the
volumetric model 100M along with near real-time MRI image data and
physical representations of the intrabody devices 80R shown in the
visualization 100v. FIG. 10 also shows that the UI 25 can allow a
user to show the model in wire/grid form.
[0169] FIG. 11 shows the display 20 with side-by-side viewing
windows, one window 20w.sub.1 showing the visualization with the
map 100M (which may be a tissue characterization map and as shown
here is rendered without the intrabody device 80 shown) and the
other window 20w.sub.2 showing at least one near RT MRI image of
local tissue during an active treatment mode (shown with two views
of the near RT images one axial and one en face.
[0170] FIGS. 12 and 13 illustrate two high-resolution active
treatment views, both showing different views, shown as an axial
and en face view of local tissue. FIG. 12 shows the tissue prior to
ablation and FIG. 13 shows the tissue during or after an ablation.
For example, during an ablation mode the circuit can use a default
viewing rule to display the near real time MR image data of the
affected tissue during an active treatment, e.g., ablation,
typically showing both en face and side views of the local tissue
and treatment (ablation tip) according to embodiments of the
present invention. In certain embodiments, the interactive
visualization map 100v and/or model 100M may not be displayed
during all or some of the ablation.
[0171] The scan planes used to generate the MR images for the
active treatment (e.g., ablation) views can be automatically
determined based on the known position of the tracking coils in 3-D
imaging space. The scan planes used for the active treatment views
of the near RT images may be pre-set scan planes 141 that are
electronically automatically selected based on the determined
location of one or more tracking coils 82c when it is in proximity
to a corresponding location of a defined target site 55t that was
previously identified (such as on planning map 137p that was
subsequently registered to the MRI imaging space).
[0172] FIG. 14 illustrates that a clinician (physician) can mark an
area on the model 100M of the interactive visualization 100v, the
mark shown as a circle toward the left side of the left window. The
marked area in FIG. 14 in one viewing window 20w.sub.1 may define
the scan plane(s) for the close-up near RT image views in the right
hand viewing window 20w.sub.2.
[0173] FIG. 15 illustrates a cardiac MRI Interventional suite 19
with an integrated cable management system that connects multiple
patient connected leads that remain in position even when a patient
is translated in or out of a magnet bore on the gantry 16 (the
magnet can be an open face or closed magnet configuration) to allow
a clinician direct access to a patient. The other ends of the leads
connect to power sources, monitors and/or controls located remote
from the patient (typically in the control room not the magnet
room). As shown in FIG. 15, the MRI interventional suite 10 can
include an IV pole 140 (typically attached to the scanner table
120) and a connection block 150 of cables 200n that are routed
through a ceiling (e.g., they extend up, through and above a
ceiling) (where "n" is typically between about 1-400, typically
between about 5-100), that connect to patch bay 135 and/or 137.
Cabling 210n for anesthesia cart 160 can also be routed through the
ceiling (where n is typically between about 1-400, typically
between about 5-100). The cabling 200n, 210n extends through the
ceiling 300 between the rooms 10a, 10b and can connect to the
remote devices 500 through a patch panel 250. In some embodiments
foot pedal cabling 220n can extend through a floor trough to the
patch panel/second room 10b as well (where "n" is typically between
about 1-100 cables). For additional description of an exemplary
cardiac suite, see, U.S. patent application Ser. No. 12/708,773,
the contents of which are hereby incorporated by reference as if
recited in full herein. The cables may also alternately be routed
under, on or over the floor, suspended on walls, employ wireless
connections and the like (and combinations of same).
[0174] In some embodiments, the system includes a navigation view
mode and an ablation view mode for cardiac procedures. The latter
viewing mode can automatically be shown on the display 20 during an
active ablation. The circuit 60c can electronically define pre-set
scan planes 141 associated with a respective target ablation site
55t which is correlated (registered) to an actual location in 3-D
space which is then electronically stored in electronic memory as
default pre-set scan planes 141 for that target location 55t. The
near RT MRI images in active therapy-view mode can automatically be
displayed when the ablation/injection or mapping catheter reaches
the corresponding physical location in the heart during the
procedure. The planned target sites 55t can also used to define the
physician view (3-D perspective), e.g., a preset view, whenever the
ablation catheter is in the location associated with the target
site. Thus, the target sites 55t identified in the planning tissue
characterization map 137p can be used to preset both associated
scan planes for the near real time MRI and the 3-D perspective view
for display without requiring further clinician input.
[0175] During some cardiac procedures, as the ablation catheter
approaches a location that corresponds to a target ablation site
55t, the circuit 60c (e.g., MR Scanner) can cause or direct the
selected scan planes to "snap to" the catheter tip location using
the preset scan planes defined for that location to obtain
real-time MR image data of the associated tissue. The scan planes
can be adjusted in response to movement of the ablation catheter
(as typically detected by tracking coils) prior to active delivery
(e.g., ablation) if the physician decides the location is
unsatisfactory. In some embodiments, the snap-to scan plane(s) can
be carried out based on the position of two closely spaced tracking
coils 82c on a distal end of the device 80. The two coils 82c can
be held on a relatively rigid substrate or catheter end with
between about 2-10 turns/coil. The tracking coils 82c can be
connected via a respective coaxial cable to the MR scanner 10S as
noted above. The snap-to or projected scan plane can be projected a
distance beyond the calculated tip location, such as between about
0-4 mm as discussed above. This embodiment may be particularly
suitable for a deflectable end ablation catheter. In other
embodiments, such as for a loop catheter, the tracking coils 82c
can be held on a loop end of the device and reside on a common
plane. The circuit 60c can be configured to define the plane based
on the location of at least three of the tracking coils 82c. The
tissue-device interface for the snap-to location can be selected to
be parallel and proximate the identified plane (e.g., between about
0-4 mm from the plane). In yet another embodiment, a device can
have between about 1-20 tracking coils along its length (e.g.,
along a distal end portion thereof). The snap-to location can be
based on a location that is tangent and in-line with at least two
of the tracking coils (as the device may deflect and the position
of at least some of the tracking coils may change relative to each
other).
[0176] The circuit 60c can adjust the scan planes as needed if the
physician moves the ablation catheter to obtain slices that show
the ablation of the lesion including side and en face views showing
substantially real-time MRI of the tissue being ablated. The slices
can include a view generated axially along the line of the catheter
and projecting forward a defined distance into tissue for the side
view (e.g., beyond the tip of the device such as between about 0-4
mm, typically about 1-2 mm). In some embodiments, the system may
automatically enable or disable ECG gating as necessary when
defining scan planes, markers, recording electrograms, and the
like.
[0177] For an optimal or proper en face view the scan plane can be
oriented to a plane that is substantially parallel to the target
tissue surface (e.g., proximate a tip of the device). This can be
done based on coordinates of the 3D segmentation/model relative to
the tip position.
[0178] To obtain a slice with a relevant scan plane for the en face
view, the device tip can be used to define one point and the
circuit could identify a plurality of additional points (e.g.,
about three more points) on the surface of the model 100M. Those
additional points can be a short radius away from the device tip
(i.e., similar to a spoke and wheel pattern). Distance of the
(three) radial points should be closely spaced relative to the
center point, particularly for curved tissue surfaces (e.g., the
cardiac walls being ablated or otherwise treated will usually be
curved, and in some cases, even have complex curves like the PV
ostia). Choosing this distance may be made with reference to
typical human cardiac anatomy, the distance of those points may be
between about 3 to 5 mm. In some particular embodiments, the
following steps may be used to obtain the en face views. [0179] 1.
Project a line forward from the most distal tracking coils on the
intrabody device. [0180] 2. Electronically generate (e.g., mark) a
temporary point where that projected line intersects the surface of
the 3D model [0181] 3. Use that temporary point of intersection as
the center of the "wheel" and calculate the location of three
points on the rim of the wheel, [0182] 4. Proscribe a temporary
plane that includes the three rim points. [0183] 5. Translate the
temporary plane until the temporary center point becomes
coterminous with the actual tip of the device (assuming that the
tip is actually against the target tissue (e.g., cardiac wall).
[0184] 6. Set the scan plane based on this calculated plane for the
en face view.
[0185] It is noted that the above steps may not be suitable where
the device is a loop catheter. When using a loop catheter as the
intrabody device with the tracking coils, the physician typically
ablates on the inside of the loop and the circuit can use the
coordinates of the tracking coils on the loop catheter to describe
the scan plane for the en face view.
[0186] In some embodiments, the system can keep track of the
shortest line from the tip of the device to the registered model,
and can even display this line in near real-time in the
rendering(s). Then, with user input, e.g. on a button press, the
circuit 60c can define a plane tangent to the model surface for the
en face view, or along this line for the axial view. Gating may be
used. The axial view may be more robust as it cuts through the
wall.
[0187] In addition to continuous collection of "new" image data,
the data can also be processed by algorithms and other means in
order to generate and present back to the surgeon in near real-time
or upon request, a substantially continuously updated, patient
specific anatomical tissue characterization map of a portion of the
heart of interest.
[0188] During ablation MR thermometry (2-D) can be used to show
real-time ablation formation taking a slice along the catheter and
showing the temperature profile increasing. It is contemplated that
2D and/or 3D GRE pulse sequences can be used to obtain the MR image
data. However, other pulse sequences may also be used.
[0189] In some embodiments, an EA (electroanatomical) map can be
obtained prior to (typically immediately prior to) the actual
interventional MRI-guided procedure either while the patient is in
the MRI scanner or from an X-ray based system from which the EA map
can be registered to a tissue characteristic map 30 and shown on
the display 20. In some embodiments, the tissue characterization
map can include, incorporate, overlay or underlay data from an
electroanatomical map (which may be imported from an X-ray imaging
modality or generated in an MRI Scanner) to define an integrated
electro and tissue characterization combination map. The electrical
activity can be detected via electrical activity sensors that can
detect impedance or other electrical parameter that can sense
fractionated or normal electrical activity in cardiac tissue as is
known to those of skill in the art. If so, the electroanatomical
map can be registered to the tissue-characterization map so that MR
data updates using MR data that is generated during the
intervention can be generated and displayed on the integrated
map.
[0190] Also, the UI 25 can be configured to allow a clinician to
select or deselect the electroanatomical map (where used) so that
the information from the electroanatomical map is electronically
stripped or removed (and/or added back in) to the tissue
characteristic map as desired. In other embodiments, the tissue
characterization map is maintained separate from the
electroanatomical map, and if used, the electroanatomical map is
shown in a separate window or screen apart from the tissue
characterization map.
[0191] In some embodiments, the device-tissue interface 100i (FIG.
1, 22A, 22B) can be visualized with a T1-weighted FLASH sequence
(T1w FLASH) to localize the tip 80t. RF or other ablative energy
can be delivered and myocardial or other target tissue changes and
lesion formation can be visualized in near real-time using a T2
weighted HASTE (T2w HASTE) sequence. Real Time (RT)-MRI sequence,
T1w FLASH and T2w HASTE image slices can be aligned to allow
visualization of the device 80 upon tissue contact or activation of
the ablation energy to allow visualization of the device 80 (e.g.,
catheter), the device-tissue interface 100i and/or the (myocardium)
tissue while receiving the therapy, e.g., ablative energy.
[0192] In some particular embodiments, during navigation mode
(rather than an ablation mode), the catheter 80 can be visualized
using a different pulse sequence from that used in the
high-resolution ablation mode, such as, for example, an RT MRI
sequence using GRE or SSFP (e.g., TrueFISP) pulse sequence with
about 5.5 fps), the tracking coils 82c can be used for spatial
orientation and positioning. Typical scan parameters for (near)
real-time include: echo time (TE) 1.5 ms, repetition time (TR) 3.5
ms, flip angle about 45 degrees or about 12 degrees, slice
thickness 5 mm, resolution 1.8 mm.times.2.4 mm, parallel imaging
with reduction factor (R) of 2. For near real-time imaging with
SSFP, a typical flip angle is about 45 degrees.
[0193] Once the device position is deemed appropriate (using
tracking coils 82c), a pulse sequence at the associated scan plane
can be used to generate high resolution visualization of the
catheter tip 80t and (myocardial) tissue interface. For example, a
T1-weighted 3D FLASH sequence (Tlw FLASH) as noted above.
Myocardial or other target tissue images during ablation or other
therapy can be acquired using an Inner Volume Acquisition (IVA)
dark-blood prepared T2-weighted HASTE (T2w HASTE) or dark-blood
prepared Turbo Spin Echo (TSE) sequence. Examples of HASTE and TSE
sequence parameters include: TE=79 ms/65 ms, TR=3 heart beats, 3
contiguous slices with thickness of about 4 mm, resolution 1.25
mm.times.1.78 mm/1.25 mm.times.1.25 mm, fat saturation using SPAIR
method, and parallel imaging with R=2, respectively.
[0194] Typical heart beat rates and free breathing can present
imaging challenges. In some embodiments, (near) RT navigation
imaging slices (e.g., GRE pulse sequence at 5.5 fps) can be aligned
with high-resolution tissue interface slices (e.g., T1 w FLASH) for
visualization of the catheter-tissue interface. Subsequently, those
slices obtained with Tlw FLASH can be aligned with those obtained
with dark-blood prepared T2w Haste images for myocardial
tissue/injury characterization during energy delivery. This
stepwise approach can allow confident localization of specific
points within the atrium and while ablating tissue and
simultaneously visualizing the tissue for near-real time assessment
of tissue injury associated with lesion formation. It is also noted
that the sequences described herein are provided as examples of
suitable sequences and it is contemplated that other known
sequences or newly developed sequences may be used for cardiac
ablation or other anatomy or interventional procedures.
[0195] In some embodiments, slices acquired with different
sequences can be interlaced to provide an interactive environment
for catheter visualization and lesion delivery, a UI can allow a
user to toggle between these views or can alternate the views based
on these image slices or navigation versus ablation or other
interventional modes/views.
[0196] As is known to those of skill in the art, there are
typically between about 60-100 lesions generated during a single
patient cardiac (AFIB) EP procedure. Other cardiac arrythmia
procedures may only require about 1 ablation or less than 60. A
typical patient interventional cardiac procedure lasts less than
about 4 hours, e.g., about 1-2 hours. Each lesion site can be
ablated for between about 30 seconds to about 2 minutes. Linear
transmural lesions (such as "continuous" drag method lesions) may
be generated and/or "spot" lesions may be generated, depending on
the selected treatment and/or condition being treated. The
continuous lesion may be formed as a series of over lapping spot
ablation lesions or as a continuous "drag" lesion.
[0197] The system can include a monitoring circuit can
automatically detect which devices are connected to the patient
patch bay. One way this can be achieved is by using ID resistors in
the patch bay and/or interface as well as in various devices that
connect thereto. The MRI scanner computer or processor or the
clinician workstation module or processor can monitor resistors via
connections CON1, CON2 and CON3. The devices 80 (FIGS. 3-5) can
have built-in resistors that modify the resistance by lines that
connect to CON1, CON2 and CON3. Variation in resistance values
helps the monitor which device is connected. Once that
determination is made the scanner may automatically load special
acquisition parameters, display parameters and update the progress
of the procedure to display on the display 20 such as at
workstation 60 (FIG. 4), for example.
[0198] Electrical isolation between the MR Scanner 10S and the
device 80 can be provided via low pass filters inside and outside
the MRI suite. As is known to those of skill in the art, components
in the MRI Suite can be connected to external components using a
waveguide built into the RF shield that encloses the MRI suite. The
ablation catheter 80 can be connected to an appropriate energy
source, such as, for example, a Stockert 70 RF generator (Biosense
Webster, Diamond Bar, Calif., USA) with MR compatible interface
circuits configured for 3T magnetic fields (where a 3T system is
used). The system can comprise an EP Suite with a Siemens Verio
system (Siemens Healthcare, Erlangen, Germany) or other suitable
scanner as well as suitable external imaging coils, such as spine
and/or body array coils as is known to those of skill in the art.
Other ablation catheters including balloon (cryoablation), laser,
ultrasound and the like may also be used in lieu of or with the RF
electrode ablation catheter. Other therapeutic catheters or devices
may be used including an injection needle catheter and the
like.
[0199] FIGS. 16A, 16B, and 17-19 illustrate exemplary embodiments
of a flexible (steerable) ablation catheter 80A as the device 80.
The ablation catheter 80A includes an elongated flexible housing or
shaft 102 having a lumen 104 (FIG. 16B) therethrough and includes
opposite distal and proximal end portions, only the distal end
portion 106 is illustrated. The distal end portion 106 includes a
tip portion 101 that contains an ablation electrode 110 at its tip
80t for ablating target tissue, and a pair of RF tracking coils
82c, individually identified as 112, 114. The distal end portion
can include a second electrode for sensing local electrical signal
or properties or the ablation electrode 110 can be bipolar and both
ablate and sense. The proximal end portion of the catheter 80A is
operably secured to a handle as is well known. The catheter shaft
102 is formed from flexible, bio-compatible and MRI-compatible
material, such as polyester or other polymeric materials. However,
various other types of materials may be utilized to form the
catheter shaft 102, and embodiments of the present invention are
not limited to the use of any particular material. In some
embodiments, the shaft distal end portion can be formed from
material that is stiffer than the proximal end portion and/or a
medial portion between the distal and proximal end portions.
[0200] The catheter 80A can be configured to reduce the likelihood
of undesired deposition of current or voltage in tissue. The
catheter 80A can include RF chokes such as a series of axially
spaced apart Balun circuits or other suitable circuit
configurations. See, e.g., U.S. Pat. No. 6,284,971, the contents of
which are hereby incorporated by reference as if recited in full
herein, for additional description of RF inhibiting coaxial cable
that can inhibit RF induced current.
[0201] The device 80A tracking coils 112, 114 (FIGS. 16A, 16B, 17)
on a distal end portion of the catheter (typically upstream of the
ablation electrode 110 on the tip of the catheter 80t) as all or
some of tracking members 82 (FIG. 3). The catheter 80A can comprise
coaxial cables 81 that connect the tracking coils to an external
device for tracking the location of the catheter in 3-D space. The
catheter 80A can include an RF wire 120 that connects the ablation
electrode 110 to an RF generator (FIGS. 30B, 31). The conductors 81
and/or RF wire 120 can include a series of back and forth segments
(e.g., it can turn on itself in a lengthwise direction a number of
times along its length), include stacked windings and/or include
high impedance circuits. See, e.g., U.S. patent application Ser.
Nos. 11/417,594; 12/047,832; and 12/090,583, the contents of which
are hereby incorporated by reference as if recited in full herein.
The conductors (e.g., coaxial cables) 81 and/or RF wire 120 can be
co-wound in one direction or back and forth in stacked segments for
a portion or all of their length.
[0202] In some embodiments, the ablation tip 80t is provided with
one or more exit ports 132 (FIG. 16A) in communication with a fluid
channel through which a fluid/solution (irrigant), such as saline,
can flow before, during, and/or after the ablation of tissue.
Fluid/solution is provided to the one or more exit ports 132 via an
irrigation lumen 134 (FIG. 18) that extends longitudinally through
the catheter shaft lumen 104 from the exit port(s) 132 to a handle.
The irrigation lumen 134 is in fluid communication with a
fluid/solution source at the proximal end portion 108 of the
catheter shaft, typically at the handle. The fluid/solution can
provide coolant and/or improve tissue coupling with the ablation
electrode 110.
[0203] In some embodiments, a pull wire 136 (FIGS. 18, 19) extends
longitudinally within the catheter shaft lumen 104 from the distal
end portion 106 to the handle at the catheter proximal end portion.
The pull wire 136 extends longitudinally within a sleeve 138 (FIG.
18) that is attached to the internal wall of the lumen 104. The
pull wire 136 is attached to the sleeve 138 near the distal end
portion 106 of the catheter 80 and otherwise is slidably disposed
within the sleeve. Pulling the pull wire 136 in a direction towards
the handle causes the tip portion 101 of the catheter to articulate
in one direction. Pushing the pull wire 136 in the opposite
direction away from the handle causes the tip portion 101 to
articulate in another different direction.
[0204] FIGS. 18 and 19 are cross sectional views of the distal end
portion 101 of the illustrated catheter 80A according to some
embodiments of the present invention. The sectional view shown in
FIG. 18 is taken further upstream from that shown in FIG. 19. FIG.
16B illustrates the location and configuration of the coaxial
cables (generally referred to as element 60) particularly referred
to as 116, 118, 126 and 128 which are connected to the tracking
coils 112, 114, 122 and 124, respectively. FIG. 16B also
illustrates the location and configuration of the RF wire 120 that
is connected to the ablation tip electrode 110 and that provides RF
energy to the ablation tip electrode 110. FIG. 17 also illustrates
the location of an exemplary thermocouple 130, and the location of
an irrigation lumen 134. FIG. 19 illustrates the location and
configuration of the coaxial cables 116, 118 which are connected to
the RF tracking coils 112, 114. FIG. 18 also illustrates the
location and configuration of the RF wire 120 connected to the
ablation tip electrode 110, the location of thermocouple 130, and
the location of irrigation lumen 134.
[0205] As discussed above with respect to FIG. 4, each tracking
coil circuit can include a PIN diode and DC blocking capacitor and
is typically located within the handle, although in other
embodiments, the tracking coil circuits can be located within the
catheter shaft lumen 104 closer to a medial or distal end portion
(not shown) or in an interface, connector or other location. Each
tracking coil circuit can be electrically connected to an MRI
scanner, and can reduce signal noise within a respective channel
caused by undesired coupling during scanner operation. In some
embodiments, the tracking coil circuit can produce about 100 ohms
impedance across an RF tracking coil when the PIN diode is shorted,
for example, by an MRI scanner during scanner operations.
[0206] In some embodiments of the present invention, RF tracking
coils 112, 114, 122, 124 may be between about 2-16 turn solenoid
coils, typically 2-10 turn solenoid coils. However, other coil
configurations may be utilized in accordance with embodiments of
the present invention. Each of the RF tracking coils 112, 114, 122,
124 can have the same number of turns or a different number of
turns, or different ones of the RF tracking coils 112, 114, 122,
124 can have different numbers of turns. It is believed that an RF
tracking coil with between about 2-4 turns at 3.0 T provides a
suitable signal for tracking purposes.
[0207] Embodiments of the present invention may be utilized in
conjunction with navigation and mapping software features. For
example, current and/or future versions of devices and systems
described herein may include features with adaptive projection
navigation and/or 3-D volumetric mapping technology, the latter may
include aspects associated with U.S. patent application Ser. No.
10/076,882, which is incorporated herein by reference in its
entirety.
[0208] FIG. 20 is a flow chart of exemplary steps that can be
implemented to carry out embodiments of the present invention.
Although the steps are shown in a particular order in the figures,
neither the order of steps in these figures or the order of these
figures is meant to indicate any required order in the
implementation of one or more of the methods and/or method steps.
Further, it will be appreciated that certain of the steps can be
carried out simultaneously rather than serially and the blocks are
stated for ease of discussion rather than as a limitation on how or
when the operations are carried out. A patient anatomical planning
map of at least a portion of a target anatomical structure can be
electronically (programmatically) provided and displayed, e.g., a
patient's heart (such as the entire heart the LA, or other desired
region) (block 300). Optionally, the map can be an interactive map
that can be configured to be rotatable, zoomed, sectioned, cropped
based on user input (block 303). User input can be accepted to
select and/or indicate (e.g., mark) at least one target treatment
site, such as target ablation sites/locations, on the map (block
305). The system can electronically and/or programmatically define
relevant scan planes for generating image slices that include the
local tissue at the at least one target treatment (ablation) site
as a preset scan plane(s) (typically prior to initiating the
MRI-guided procedure) (block 310). The preset scan planes can be
subsequently used by the MRI Scanner for generating near real time
MRI images of local tissue (such as when an ablation catheter is at
the corresponding site).
[0209] The preset scan planes can be defined based on a UI that
allows a clinician/physician to touch a screen to mark/indicate or
otherwise select target ablation sites on the planning map of the
patient's anatomical structure of interest. Alternatively or
additionally, a selectable list of procedures for particular
conditions which having defined treatment sites can be provided and
a user can select the corresponding procedure for the patient
whereby, in response, suggested treatment sites can be
electronically shown on the planning map (block 302). Alternatively
or additionally, the system can apply an adjustable grid or
template that can be electronically adjusted via a user or
automatically morphed to fit patient-specific tissue contour (block
304).
[0210] The planning map can comprise data from one or more of a
tissue characterization map and/or an electroanatomical map. A
clinician can generate the target treatment sites on the planning
map outside 3-D image space used for the MRI guided procedure and
the map with the associated pre-set scan planes can subsequently be
registered to the 3-D image space.
[0211] The system can electronically register the planning map to
the MRI 3-D image space (using manual alignment or automatic
alignment) proximate in time to initiating the MRI-guided procedure
and electronically adjust the identified pre-set scan planes
associated with the planning map (block 322). The MRI Scanner can
use one or more of the pre-set scan planes to obtain near real-time
MRI image data during the MRI guided procedure.
[0212] During the MRI-guided procedure, the location of an
intrabody device (e.g., intracardiac ablation catheter) can be
tracked and a physical representation of the device rendered and
shown in a visualization with respect to the registered map (block
315). As the distal end of the intrabody device (e.g., a tip
electrode) approaches the proximity of one of the previously
indicated target locations or resides proximate one of the selected
target sites identified by the planning map, the MRI Scanner is
directed to scan ("snap to") relevant local tissue using the
associated preset scan plane(s) (block 320). Optionally, the MR
Scanner can be programmatically directed to select scan planes that
includes a slice that is aligned with an axial direction of the
ablation catheter and that projects forward from the distal tip of
the device (block 322). That is, a device-tissue interface location
proximate a tip location of the device in the three dimensional
image space is electronically calculated using the identified
locations of the tracking coils. The calculating step projects
axially forward a defined distance beyond the tip to define the
device-tissue interface and at least one scan plane used to obtain
the MR image data for the near RT images during and/or proximate in
time to delivery of a therapeutic treatment and/or a diagnostic
procedure is electronically defined using the calculated location.
A user (via a UI) may be able to select the desired projection
forward distance for the scan plane/slice location. The system may
include a default distance (e.g., the end of the tip or distance
forward=about 0 or 0.1 mm) that can be adjusted prior to or during
a procedure.
[0213] Also optionally, during active therapy (e.g., ablation) at
least one near real-time MR lesion image (close-up view) generated
using a pre-set scan plane(s) can be displayed to show tissue being
treated (e.g., ablated) by the device in a window on a display at
the workstation (block 325). This may be a high resolution image of
the local tissue. Optionally, during the treatment, both an en face
and side view of the local tissue (e.g., showing a lesion being
formed in tissue) can be displayed (block 326).
[0214] Although described primarily herein with respect to cardiac
EP procedures using ablation electrodes, other procedures and other
ablation techniques can be used, such as, for example, cryogenic
(e.g., cryoablation typically with an expandable balloon), laser,
microwave, and even chemical ablation. In some embodiments, the
ablation can be carried out using ultrasound energy. In particular
embodiments, the ablation may be carried out using HIFU (High
Intensity Focused Ultrasound). When MRI is used this is sometimes
called Magnetic Resonance-guided Focused Ultrasound, often
shortened to MRgFUS. This type of energy using a catheter to direct
the energy to the target cardiac tissue can heat the tissue to
cause necrosis. Similarly, the systems and/or components described
herein can be useful for other MRI guided surgical intervention
procedures, including, for example, delivering biologics or other
drug therapies to target locations in tissue using MRI.
[0215] Some interventional tools may include an MRI receive antenna
for improved SNR of local tissue. In some embodiments, the antenna
has a focal length or signal-receiving length of between about 1-5
cm, and typically is configured to have a viewing length to receive
MRI signals from local tissue of between about 1-2.5 cm. The MRI
antenna can be formed as comprising a coaxial and/or triaxial
antenna. However, other antenna configurations can be used, such
as, for example, a whip antenna, a coil antenna, a loopless
antenna, and/or a looped antenna. See, e.g., U.S. Pat. Nos.
5,699,801; 5,928,145; 6,263,229; 6,606,513; 6,628,980; 6,284,971;
6,675,033; and 6,701,176, the contents of which are hereby
incorporated by reference as if recited in full herein. See also
U.S. Patent Application Publication Nos. 2003/0050557;
2004/0046557; and 2003/0028095, the contents of which are also
hereby incorporated by reference as if recited in full herein.
Image data can also include image data obtained by a
trans-esophageal antenna catheter during the procedure. See,
e.g.,U.S. Pat. No. 6,408,202, the contents of which are hereby
incorporated by reference as if recited in full herein.
[0216] As discussed above, embodiments of the present invention may
take the form of an entirely software embodiment or an embodiment
combining software and hardware aspects, all generally referred to
herein as a "circuit" or "module." Furthermore, the present
invention may take the form of a computer program product on a
computer-usable storage medium having computer-usable program code
embodied in the medium. Any suitable computer readable medium may
be utilized including hard disks, CD-ROMs, optical storage devices,
a transmission media such as those supporting the Internet or an
intranet, or magnetic storage devices. Some circuits, modules or
routines may be written in assembly language or even micro-code to
enhance performance and/or memory usage. It will be further
appreciated that the functionality of any or all of the program
modules may also be implemented using discrete hardware components,
one or more application specific integrated circuits (ASICs), or a
programmed digital signal processor or microcontroller. Embodiments
of the present invention are not limited to a particular
programming language.
[0217] Computer program code for carrying out operations of data
processing systems, method steps or actions, modules or circuits
(or portions thereof) discussed herein may be written in a
high-level programming language, such as Python, Java, AJAX
(Asynchronous JavaScript), C, and/or C++, for development
convenience. In addition, computer program code for carrying out
operations of exemplary embodiments may also be written in other
programming languages, such as, but not limited to, interpreted
languages. Some modules or routines may be written in assembly
language or even micro-code to enhance performance and/or memory
usage. However, embodiments are not limited to a particular
programming language. It will be further appreciated that the
functionality of any or all of the program modules may also be
implemented using discrete hardware components, one or more
application specific integrated circuits (ASICs), or a programmed
digital signal processor or microcontroller. The program code may
execute entirely on one (e.g., a workstation computer or a
Scanner's computer), partly on one computer, as a stand-alone
software package, partly on the workstation's computer or Scanner's
computer and partly on another computer, local and/or remote or
entirely on the other local or remote computer. In the latter
scenario, the other local or remote computer may be connected to
the user's computer through a local area network (LAN) or a wide
area network (WAN), or the connection may be made to an external
computer (for example, through the Internet using an Internet
Service Provider).
[0218] The present invention is described in part with reference to
flowchart illustrations and/or block diagrams of methods, apparatus
(systems) and computer program products according to embodiments of
the invention. It will be understood that each block of the
flowchart illustrations and/or block diagrams, and combinations of
blocks in the flowchart illustrations and/or block diagrams, can be
implemented by computer program instructions. These computer
program instructions may be provided to a processor of a general
purpose computer, special purpose computer, or other programmable
data processing apparatus to produce a machine, such that the
instructions, which execute via the processor of the computer or
other programmable data processing apparatus, create means for
implementing the functions/acts specified in the flowchart and/or
block diagram block or blocks.
[0219] These computer program instructions may also be stored in a
computer-readable memory that can direct a computer or other
programmable data processing apparatus to function in a particular
manner, such that the instructions stored in the computer-readable
memory produce an article of manufacture including instruction
means which implement the function/act specified in the flowchart
and/or block diagram block or blocks.
[0220] The computer program instructions may also be loaded onto a
computer or other programmable data processing apparatus to cause a
series of operational steps to be performed on the computer or
other programmable apparatus to produce a computer implemented
process such that the instructions which execute on the computer or
other programmable apparatus provide steps for implementing some or
all of the functions/acts specified in the flowchart and/or block
diagram block or blocks.
[0221] The flowcharts and block diagrams of certain of the figures
herein illustrate exemplary architecture, functionality, and
operation of possible implementations of embodiments of the present
invention. In this regard, each block in the flow charts or block
diagrams represents a module, segment, or portion of code, which
comprises one or more executable instructions for implementing the
specified logical function(s). It should also be noted that in some
alternative implementations, the functions noted in the blocks may
occur out of the order noted in the figures. For example, two
blocks shown in succession may in fact be executed substantially
concurrently or the blocks may sometimes be executed in the reverse
order or two or more blocks may be combined, depending upon the
functionality involved.
[0222] The workstation 60 and/or interface 44 may also include a
decoupling/tuning circuit that allows the system to cooperate with
an MRI scanner 10 and filters and the like. See, e.g., U.S. Pat.
Nos. 6,701,176; 6,904,307 and U.S. Patent Application Publication
No. 2003/0050557, the contents of which are hereby incorporated by
reference as if recited in full herein.
[0223] In some embodiments, the intrabody device is configured to
allow for safe MRI operation so as to reduce the likelihood of
undesired deposition of current or voltage in tissue. The tool can
include RF chokes such as a series of axially spaced apart Balun
circuits or other suitable circuit configurations. See, e.g., U.S.
Pat. No. 6,284,971, the contents of which are hereby incorporated
by reference as if recited in full herein, for additional
description of RF inhibiting coaxial cable that can inhibit RF
induced current. The conductors connecting electrodes or other
components on or in the catheter (or other interventional device)
can also include a series of back and forth segments (e.g., the
lead can turn on itself in a lengthwise direction a number of times
along its length) and/or include high impedance circuits. See,
e.g., U.S. patent application Ser. Nos. 11/417,594; 12/047,602; and
12/090,583, the contents of which are hereby incorporated by
reference as if recited in full herein.
[0224] The intrabody devices 80 can be used and/or deliver desired
cellular, biological, and/or drug therapeutics to a target
area.
[0225] FIGS. 21 and 22 are schematic illustrations of circuits or
data processing systems 490, 490' that can be used to carry out one
or more actions/steps contemplated by embodiments of the present
invention. The circuits and/or data processing systems 490, 490'
may be incorporated in one or more digital signal processors in any
suitable device or devices. As shown in FIGS. 21, 22, the processor
410 communicates with an MRI scanner 10S and with memory 414 via an
address/data bus 448. The processor 410 can be any commercially
available or custom microprocessor. The memory 414 is
representative of the overall hierarchy of memory devices
containing the software and data used to implement the
functionality of the data processing system. The memory 414 can
include, but is not limited to, the following types of devices:
cache, ROM, PROM, EPROM, EEPROM, flash memory, SRAM, and DRAM.
[0226] As shown in FIGS. 21 and 22 illustrate that the memory 414
may include several categories of software and data used in the
data processing system: the operating system 449; the application
programs 454; the input/output (I/O) device drivers 458; and data
456. The data 456 can also include intrabody device dimensions
and/or form factors (e.g., distance of a tracking coil to the tip
of the device) and/or patient-specific image data 455. FIG. 21 also
illustrates the application programs 454 can include a Patient
Planning Map Module 450, a Pre-Set Scan Plane Module 451, a
Tracking Module 452 and a UI Module 452. FIG. 22 illustrates the
application programs can include the Pre-Set Scan Plane Module 451,
a tracking location calculation module 1450, and an Interactive
Visualization Module 1452, and the UI Module 452.
[0227] As will be appreciated by those of skill in the art, the
operating systems 449 may be any operating system suitable for use
with a data processing system, such as OS/2, AIX, or zOS from
International Business Machines Corporation, Armonk, N.Y., Windows
CE, Windows NT, Windows95, Windows98, Windows2000, WindowsXP,
Windows Visa, Windows7, Windows CE or other Windows versions from
Microsoft Corporation, Redmond, Wash., Palm OS, Symbian OS, Cisco
IOS, VxWorks, Unix or Linux, Mac OS from Apple Computer, LabView,
or proprietary operating systems. For example, VxWorks which can
run on the Scanner's sequence generator for precise control of
pulse sequence waveform timings.
[0228] The I/O device drivers 458 typically include software
routines accessed through the operating system 452 by the
application programs 454 to communicate with devices such as I/O
data port(s), data storage 456 and certain memory 414 components.
The application programs 454 are illustrative of the programs that
implement the various features of the data processing system and
can include at least one application, which supports operations
according to embodiments of the present invention. Finally, the
data 456 represents the static and dynamic data used by the
application programs 454, the operating system 449, the I/O device
drivers 458, and other software programs that may reside in the
memory 414.
[0229] While the present invention is illustrated, for example,
with reference to the Modules 450-452 and/or 451, 452, 1450, 1452,
being application programs, as will be appreciated by those of
skill in the art, other configurations may also be utilized while
still benefiting from the teachings of the present invention. For
example, the Modulesand/or may also be incorporated into the
operating system 449, the I/O device drivers 458 or other such
logical division of the data processing system. Thus, the present
invention should not be construed as limited to the configuration
of FIGS. 21 and/or 22 which are intended to encompass any
configuration capable of carrying out the operations described
herein. Further, one or more of modules, i.e., Modules can
communicate with or be incorporated totally or partially in other
components, such as an MRI scanner 10S, workstation 60 and/or
circuit 60c and/or interface 44 or a remote or other local
processor.
[0230] The I/O data port can be used to transfer information
between the data processing system, the workstation, the MRI
scanner, the ablation catheter and another computer system or a
network (e.g., the Internet) or to other devices controlled by a
processor. These components may be conventional components such as
those used in many conventional data processing systems, which may
be configured in accordance with the present invention to operate
as described herein.
[0231] Non-Limiting Examples of Tissue Characterization Maps will
be discussed below.
Thermal Tissue Characterization Map
[0232] The thermal tissue characterization map can be based on
thermal status at a given point in time or may be provided as a
composite of heating of different tissue locations at different
times (e.g., during and/or after ablation of different points at
different times of the ablation procedure). The thermal map can be
registered to a location of the internal ablation catheter (e.g.,
tip) at different times so that the location of the ablation
catheter tip is correlated to the thermal activity/status at that
location at that time as that is the time frame that the image data
for that region illustrating increased thermal activity/heating is
generated. That is, the image scan planes are taken to show the
tissue at the location of the ablation catheter tip. The image scan
planes are typically projected forward a known distance from the
tracking coil so that the lesion tissue in front of the ablation
tip is imaged.
[0233] The MR thermal data can be obtained using temperature
imaging techniques (MR thermometry) to show temperature or phase
variance. Examples of pulse sequences include, for example, SSFP
and 2D GRE.
Contrast-Based Tissue Characterization Maps
[0234] Tissue damage can be shown or detected using MR image data
based on contrast agents such as those agents that attach to or are
primarily retained in one of, but not both, healthy and unhealthy
tissue, e.g., the contrast agent is taken up by, attaches to, or
resides or stays in one more than in the other so that MR image
data will visually indentify the differences (using pixel
intensity). The contrast agent can be one or more of any known or
future developed biocompatible agent, currently typically
gadolinium, but may also include an antibody or derivative or
component thereof that couples to an agent and selectively binds to
an epitope present in one type of tissue but not the other (e.g.,
unhealthy tissue) so that the epitope is present in substantially
amounts in one type but not the other. Alternatively, the epitope
can be present in both types of tissue but is not susceptible to
bind to one type by steric block effects.
[0235] The contrast based tissue characteristic maps can allow a
clinician to assess both scar formation (isolation of the PV) and
the volume of enhancement on a LA myocardial volume may indicate a
poor outcome prediction and a clinician may decide to continue
ablating.
[0236] Examples of pulse sequences that can be used for delayed
hyper-enhancement MRI include, for example, gradient echo, SSFP
(steady state free precession) such as TrueFISP on Siemens MRI
Scanners, FIESTA on GE MRI Scanners, and b-FFE on Philips MRI
Scanners.
[0237] In some embodiments, the system/circuit can employ
interactive application of non-selective saturation to show the
presence of a contrast agent in near real-time scanning. This
option can help, for example, during image-guided catheter
navigation to target tissue that borders scar regions. See, e.g.,
Dick et al., Real Time MRI enables targeted injection of labeled
stem cells to the border of recent porcine myocardial infarction
based on functional and tissue characteristics, Proc. Intl. Soc.
Mag. Reson. Med. 11, p. 365 (2003); Guttman et al., Imaging of
Myocardial Infarction for Diagnosis and Intervention Using
Real-Time Interactive MRI Without ECG-Gating or Breath-Holding,
Mag. Reson. Med, 52: 354-361 (2004), and Dick and Guttman et al.,
Magnetic Resonance Fluoroscopy Allows Targeted Delivery of
Mesenchymal Stem Cells to Infarct Borders in Swine, Circulation,
2003; 108:2899-2904, which describe, inter alia, imaging techniques
used to show regions of delayed enhancement in (near) real-time
scans. The contents of these documents are hereby incorporated by
reference as if recited in full herein.
Edema Tissue Characterization Maps
[0238] After (and/or during) ablation, tissue will typically have
edema. This can be detected in MRI using, for example, pulse
sequences such as T2-weighted Turbo-Spin-Echo, HASTE (a Siemens
term), SSFP, or T2-weighted gradient recalled echo (GRE).
[0239] Some tissue characteristic maps may show edema and thermal
maps overlaid or otherwise combined as a composite map that can be
used to evaluate a procedure. For example, to visually assess
whether there is complete or incomplete scar formation to isolate
pulmonary veins. It is believed that complete scar formation to
isolate PV is associated with a better prognosis for AFIB.
Heart Wall Motion Tissue Characterization Maps
[0240] MRI can be used to assess heart wall motion. Abnormal motion
can be visually indicated on the tissue characterization map.
Examples of pulse sequences that may be used to determine heart
wall motion include, for example, DENSE, HARP and MR tagging.
[0241] While embodiments have been primarily discussed with respect
to an MRI-guided cardiac systems, the systems can be used for other
anatomical regions and/or deliver or apply other therapies and may
also be used for diagnostic procedures. For example, the systems
may be used for the esophagus and anatomy near the esophagus, e.g.,
the aorta, coronary arteries, mediastinum, the hepaticobiliary
system or the pancreas in order to yield anatomic information about
the structures in those areas, "pancreaticohepaticobiliary"
structures (collectively the structures of the liver, gallbladder,
bile ducts and pancreas), the tracheobronchopulmonary structure
(structures including the lungs and the tracheobronchial tree), the
nasopharynx system (e.g., a device introduced transnasally may be
adapted for evaluating the arterial circle of Willis and related
vascular structures for abnormalities, for example congenital or
other aneurysms), the proximal aerodigestive system or the thyroid,
the ear canal or the Eustachian tube, permitting anatomic
assessment of abnormalities of the middle or inner ear, and further
permitting evaluation of adjacent intracranial structures and
lesions.
[0242] Embodiments of the systems and methods of the present
invention may be particularly useful in those lesions whose extent
is not readily diagnosed, such as basal cell carcinomas. These
lesions may follow nerves into the orbit or into the intracranial
area, extensions not evident with traditional imaging modalities to
the surgeon undertaking the resection to provide real time
information to the resecting surgeon or the surgeon performing a
biopsy as to the likely areas of lymph node invasion.
[0243] It is also contemplated that the systems can be used in the
"head and neck" which refers collectively to those structures of
the ear, nose and throat and proximal aerodigestive system as
described above, traditionally falling within the province of
otorhinolaryngology. The term "head and neck," as used herein, will
further include those structures of the neck such as the thyroid,
the parathyroid, the parotid and the cervical lymph nodes, and will
include also the extracranial portions of the cranial nerves,
including but not limited to the facial nerve, this latter nerve
being included from its entry into the internal auditory meatus
outward. The term "head and neck, as used herein, will also include
those structures of the orbit or of the globe, including the
oculomotor muscles and nerves, lacrimal glands and adnexal
structures. As used herein, the term "head and neck" will further
include those intracranial structures in proximity to the aforesaid
head and neck structures. These intracranial structures may
include, as examples, the pituitary gland, the pineal gland, the
nuclei of various cranial nerves, the intracranial extensions of
the cranial nerves, the cerebellopontine angle, the arterial circle
of Willis and associated vascular structures, the dura, and the
meninges.
[0244] In yet other embodiments, the systems can be used in the
genourinary system, such as the urethra, prostate, bladder, cervix,
uterus, and anatomies in proximity thereto. As used herein, the
term "genitourinary" shall include those structures of the urinary
tract, the male genital system and the female genital system. The
urinary tract structures include the urethra, the bladder, the
ureters, the kidney and related neural, vascular, lymphatic and
adnexal structures. The male genital tract includes the prostate,
the seminal vesicles, the testicles, the epididymis and related
neural, vascular, lymphatic, ductal and adnexal structures. The
female genital tract includes the vagina, the cervix, the
non-gravid and gravid uterus, the fallopian tubes, the ovaries, the
ova, the fertilized egg, the embryo and the fetus. The term
"genitourinary" further refers to those pelvic structures that
surround or support the abovementioned structures, such as the
paraurethral tissues, the urogenital diaphragm or the musculature
of the pelvic floor. The devices can be configured for
transurethral placement for evaluation and treatment of female
urinary incontinence or bleeding and may use high resolution images
of the local tissue, e.g., different layers of the paraurethral
tissues. It is understood, for example, that a clearly identified
disruption in the muscle layers surrounding the urethra may be
repaired surgically, but also can be guided by detailed anatomic
information about the site of the abnormality. The devices may also
be configured for placement in the genitourinary system such as
into the ureter or renal pelvis, urinary tract, or transvaginal use
in analysis of the vagina and anatomies in proximity thereto. For
example, transvaginal or transcervical endouterine placement may be
useful in the diagnosis of neoplasia, in the diagnosis and
treatment of endometriosis and in the evaluation of infertility or
diagnosis, treatment of pelvic disorders resulting in pelvic pain
syndromes, evaluation/treatment of cervical and uterine
malignancies and to determine their stages, obstetric use such as
permitting anatomic evaluation of mother and fetus.
[0245] In another embodiment, the systems can be used for
evaluating and/or treating the rectum or colon, typically by the
transrectal route that can be inserted through the anus to a level
within the rectum, sigmoid or descending colon where the designated
anatomy can be visualized. For example, this approach may be used
to delineate the anatomy of the prostate gland, and may further
guide the biopsy or the extirpation of lesions undertaken
transrectally or transurethrally.
[0246] In other embodiments, the systems and methods of the present
invention may be used for the evaluation, diagnosis or treatment of
a structure in the gastrointestinal system, or for the evaluation,
diagnosis or treatment of a region of the gastrointestinal anatomy.
As used herein, the term "gastrointestinal" shall include
structures of the digestive system including the esophagus, the
stomach, the duodenum, jejunum and ileum (small intestine), the
appendix and the colon. The term "gastrointestinal anatomy" shall
refer to the structures of the gastrointestinal system as well as
the surrounding supporting structures such as the mesentery and the
enclosing structures such as the peritoneum, the diaphragm and the
retroperitoneum. Disorders of the gastrointestinal system are
well-known in the medical arts, as are disorders of the
gastrointestinal anatomy. In an exemplary embodiment, the intrabody
device may be passed into the stomach.
[0247] In other embodiments, the systems and methods of the present
invention may be used for the evaluation, diagnosis and treatment
of the vascular system. The vascular system is understood to
include the blood vessels of the body, both arterial and venous.
The vascular system includes both normal and abnormal blood
vessels, named and unnamed vessels, and neovascularization. Access
to the vascular system takes place using techniques familiar to
practitioners of ordinary skill in the art. The present invention
may be used in blood vessels of all size and the intrabody devices
may be dimensionally adapted to enter smaller caliber vessels, such
as those comprising the distal coronary circulation, the
intracranial circulation, the circulation of the distal extremities
or the distal circulation of the abdominal viscera. According to
these systems and methods, furthermore, positioning an intrabody
device within the vascular system may be useful for evaluating,
diagnosing and treating conditions in structures adjacent to or in
proximity to the particular vessel within which the device is
situated. Such structures are termed "perivascular structures." As
an example, a device placed within a coronary artery may provide
information about the vessel itself and about the myocardium that
is perfused by the vessel or that is adjacent to the vessel. A
device thus positioned may be able to guide therapeutic
interventions directed to the myocardial tissue, and may also be
able to guide endovascular or extravascular manipulations directed
to the vessel itself, It will be readily appreciated by those of
ordinary skill in the art that a number of other applications exist
or may be discovered with no more than routine experimentation
using the systems and methods of the present invention within the
vascular system,
[0248] It is understood that access to anatomic structures using
the systems, devices modified to fit the intended purpose and
anatomy, and methods of the present invention may be provided via
naturally occurring anatomic orifices or lumens, as indicated in
the examples above. It is further understood, however, that access
to anatomic structures using these systems and methods may be
additionally provided using temporary or permanent orifices that
have been created medically,
[0249] Further, the methods and systems may cooperate with robotic
driven systems rather than manual systems.
[0250] The aforesaid embodiments are understood to be exemplary
only. Other embodiments wherein MRI probes may be used within body
areas such as body canals, cavities, lumens, passageways, actual or
potential spaces will be apparent to practitioners of ordinary
skill in the relevant arts
[0251] In the drawings and specification, there have been disclosed
embodiments of the invention and, although specific terms are
employed, they are used in a generic and descriptive sense only and
not for purposes of limitation, the scope of the invention being
set forth in the following claims, Thus, the foregoing is
illustrative of the present invention and is not to be construed as
limiting thereof. Although a few exemplary embodiments of this
invention have been described, those skilled in the art will
readily appreciate that many modifications are possible in the
exemplary embodiments without materially departing from the novel
teachings and advantages of this invention. Accordingly, all such
modifications are intended to be included within the scope of this
invention as defined in the claims. In the claims,
means-plus-function clauses, where used, are intended to cover the
structures described herein as performing the recited function and
not only structural equivalents but also equivalent structures.
Therefore, it is to be understood that the foregoing is
illustrative of the present invention and is not to be construed as
limited to the specific embodiments disclosed, and that
modifications to the disclosed embodiments, as well as other
embodiments, are intended to be included within the scope of the
appended claims. The invention is defined by the following claims,
with equivalents of the claims to be included therein.
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