U.S. patent application number 12/919220 was filed with the patent office on 2010-12-30 for biopsy guidance by image-based x-ray guidance system and photonic needle.
This patent application is currently assigned to KONINKLIJKE PHILIPS ELECTRONICS N.V.. Invention is credited to Drazenko Babic, Bernardus Hendrikus Wilhelmus Hendriks.
Application Number | 20100331782 12/919220 |
Document ID | / |
Family ID | 40565037 |
Filed Date | 2010-12-30 |
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United States Patent
Application |
20100331782 |
Kind Code |
A1 |
Hendriks; Bernardus Hendrikus
Wilhelmus ; et al. |
December 30, 2010 |
BIOPSY GUIDANCE BY IMAGE-BASED X-RAY GUIDANCE SYSTEM AND PHOTONIC
NEEDLE
Abstract
A system for providing integrated guidance for positioning a
needle in a body has two levels of guidance: a coarse guidance and
a fine guidance. The system comprises a non-invasive imaging system
for obtaining an image of the biopsy device in the body, for
providing the coarse guidance. Furthermore, the system comprises an
optical element mounted on the needle for obtaining optical
information discriminating tissue in the body, for providing the
fine guidance.
Inventors: |
Hendriks; Bernardus Hendrikus
Wilhelmus; (Eindhoven, NL) ; Babic; Drazenko;
(Eindhoven, NL) |
Correspondence
Address: |
PHILIPS INTELLECTUAL PROPERTY & STANDARDS
P.O. BOX 3001
BRIARCLIFF MANOR
NY
10510
US
|
Assignee: |
KONINKLIJKE PHILIPS ELECTRONICS
N.V.
EINDHOVEN
NL
|
Family ID: |
40565037 |
Appl. No.: |
12/919220 |
Filed: |
February 25, 2009 |
PCT Filed: |
February 25, 2009 |
PCT NO: |
PCT/IB09/50752 |
371 Date: |
August 25, 2010 |
Current U.S.
Class: |
604/164.12 ;
382/131 |
Current CPC
Class: |
A61B 17/3417 20130101;
A61B 2090/3614 20160201; A61B 5/0035 20130101; A61B 8/5238
20130101; A61B 5/0066 20130101; A61B 8/0841 20130101; A61B 5/4381
20130101; A61B 8/0833 20130101; A61B 6/12 20130101; A61B 10/0275
20130101; A61B 8/5261 20130101; A61B 5/055 20130101; A61B 5/6852
20130101; A61B 5/6848 20130101; A61B 6/5247 20130101; A61B 6/032
20130101 |
Class at
Publication: |
604/164.12 ;
382/131 |
International
Class: |
A61M 5/178 20060101
A61M005/178; G06K 9/00 20060101 G06K009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 3, 2008 |
EP |
08152217.9 |
Jun 5, 2008 |
EP |
08157678.7 |
Claims
1. A system for integrated guidance for positioning a biopsy device
in a body, the system comprising: an imaging device (500) for
coarse guidance, providing images of body structures, an analyze
device (20) for fine guidance, comprising an optical element (220)
and providing information discriminating tissue of the body, and a
biopsy device (100, 200) being an elongate element with a tip
portion, wherein the biopsy device (100, 200) is adapted to be
visualized by the imaging device (500), and wherein the optical
element (220) is in the tip portion of the biopsy device (100,
200).
2. The system as claimed in claim 1, wherein the biopsy device
(100, 200) comprises one of a biopsy needle or a hollow shaft (210)
adapted to receive a needle (240) for taking a tissue sample.
3. The system as claimed in claim 1, wherein the optical element of
the analyze device (20) comprises an optical fiber (30, 40,
220).
4. The system as claimed in claim 3, wherein the analyze device
(20) further comprises a console for spectroscopy (22), wherein the
console and the fiber (40, 220) are connected to each other.
5. The system as claimed in claim 4, wherein the console for
spectroscopy (22) is adapted to provide information from one of the
group consisting of reflectance spectroscopy, fluorescence
spectroscopy, autofluorescence spectroscopy, differential path
length spectroscopy, Raman spectroscopy, optical coherence
tomography, light scattering spectroscopy, and multi-photon
fluorescence spectroscopy.
6. The system as claimed in claim 1, wherein the imaging device
(500) is a non-invasive imaging modality being one of the group
consisting of an X-ray device, a computer tomography device, a
magnet resonance tomography device, and an ultrasound device.
7. The system as claimed in claim 1, wherein the information
provided by the analyze device (20) is registered in image provided
by the imaging device (500).
8. A biopsy device (100, 200) comprising at least one of: a
structure and material capable to be visualized by an imaging
device (500), and an optical fiber (30, 40, 220) integrated in the
biopsy device, capable of emitting and receiving of light, wherein
an end of the optical fiber is located at a tip portion of the
biopsy device.
9. The biopsy device as claimed in claim 8, wherein the biopsy
device (100) is a biopsy needle.
10. The biopsy device as claimed in claim 8, wherein the biopsy
device (200) comprises a hollow shaft (210) adapted to receive a
needle (240) for taking a tissue sample.
11. A method of positioning a biopsy device according to claim 8 in
a body having tissue, the method comprising the steps of:
manipulating the biopsy device (100, 200) in a body, wherein the
biopsy device comprises an optical fiber (30, 40, 220), visualizing
structures of the body and the biopsy device, by means of a
non-invasive imaging system (500), coarse guiding the biopsy device
on the basis of the visualization, analyzing the tissue adjacent a
tip portion of the biopsy device, by means of an analyze device
(20) having a spectroscopy console, providing optical information
on the basis of the analysis, fine positioning the biopsy device on
the basis of the information from the analyze device.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a system for integrated
guidance for positioning a biopsy device in a body, a biopsy device
and a method of positioning the same. Particularly, the invention
relates to a system for and a method of providing integrated
guidance for positioning the biopsy device in a body.
BACKGROUND OF THE INVENTION
[0002] For correct diagnosis of various cancer diseases biopsies
are taken. This can either be done via a lumen of an endoscope or
via needle biopsies. An example of a needle biopsy is shown in FIG.
1, where a biopsy is taken from the prostate via the rectum. In
order to find the correct position to take the biopsy, various
imaging modalities are used such as X-ray, MRI or ultrasound. In
case of prostate cancer in most cases the biopsy is guided by
ultrasound (see FIG. 1). Although helpful, these methods of
guidance are far from optimal.
[0003] There are two major problems directly related to the
biopsy:
[0004] The resolution is limited and, furthermore, these imaging
modalities cannot in most cases discriminate normal and neoplastic
tissue and further differentiate between benign and malignant
tissue. As a result of that, there is a high level of uncertainty
whether an appropriate tissue specimen is taken.
[0005] In addition to that, the biopsies are often taken blindly
which leads to an additional uncertainty whether the lesion has
been hit by the needle. It is clear that from the point of view of
guidance improvement is required to guide the biopsy needle to the
correct position in the tissue.
[0006] If the specimen taken appears to be cancerous, in most cases
this cancerous tissue will be removed by surgery (especially when
the tumor is well localized). Here another problem arises due to
the fact that the surgeon can only use their eyes and hands
(palpation) to find the tumor and have to rely on the information
of pre-recorded images. These pre-recorded images provide
information on the position of the tumor, but do not show the tumor
boundaries. In order to help the surgeon to find the boundary a
localization-wire is used. Again guiding the localization wire to
the correct position is difficult.
[0007] It may be particularly difficult to find the boundaries of
the tumor, in fact it is virtually impossible. As a result of that,
the surgeon removes a significant amount of tissue around the core
of the tumor to make sure that the entire tumor mass is removed.
Although removing an additional amount of tissue around the tumor
will indeed lead in most cases to complete removal, the surgeon is
never sure. The number of recurrences of the cancer after removal
is 30%, which indicates that some parts of the tumor remained in
place and caused further tumor re-growth. One could of course
increase the amount of tissue to be removed but this is in several
cases difficult. In some cases vital structures are present in the
tissue (nerves, important blood vessels, brain tissue). The surgeon
has then to decide whether the malfunctioning due to the additional
tissue outweighs the risk of not completely removing the tumor. It
is important to note that when resection is not complete, the
surgeon has, in fact, cut through the tumor and may cause further
dissemination of the tumor. A second operation to repair these
damages is very invasive and leads to sever side effects such as
mutilation and loss of function of body and/or mind.
[0008] The biopsy device may also be used as a device for
administering drugs or a therapy (like percutaneously using RF,
microwave or cryoablation) at a certain position in the body
without removing tissue, for instance for injecting a fluid at the
correct location of the affected body part. The same drawbacks
apply for these interventions where it is difficult to guide the
biopsy device to the correct location.
SUMMARY OF THE INVENTION
[0009] It has been found that taking a biopsy in accordance with
the above methods may have a number of drawbacks, such as [0010]
difficulties in guiding the biopsy needle to a centre of the tissue
to be investigated; [0011] difficulties in delineating the tumor
boundaries (shape and size of tumor); [0012] difficulties in taking
specimen out of the body for the histological analysis without
dissemination of the tumor.
[0013] It may be an object to provide for an improved guidance of a
biopsy device.
[0014] This is achieved by the subject matter of the respective
independent claims. Further exemplary embodiments are described in
the respective dependent claims.
[0015] Generally, a system according to the invention comprises an
imaging device providing images of body structures, an analyze
device comprising an optical element and providing information
discriminating tissue of the body, and a biopsy device. The biopsy
device is adapted to be traced by the imaging device, and the
optical element is integrated in the biopsy device.
[0016] In other words, the invention provides an integrated system
comprising a non-invasive imaging modality (i.e. X-ray, CT, MRI,
Ultrasound) that can image the inside of the body, a biopsy device
including at least one optical element, the element being connected
to a console capable of probing the tissue in front of or near the
biopsy device with an optical modality (i.e. reflectance
spectroscopy, fluorescence spectroscopy, autofluorescence
spectroscopy, differential path length spectroscopy, Raman
spectroscopy, optical coherence tomography, light scattering
spectroscopy, multi-photon fluorescence spectroscopy), wherein the
console is part of the integrated system. The non-invasive imaging
modality can image the biopsy device inside the body, allowing
coarse guidance of the biopsy device based on the non-invasive
imaging modality. The analyze device is used to fine position the
tip portion of the biopsy device in the targeted tissue.
Preferably, the optical information is registered into the image of
the non-invasive imaging modality. Preferably, in case the
non-invasive imaging modality allows 3-dimensional imaging, the
optical information is registered in the 3-dimensional coordinate
frame of the image.
[0017] The biopsy device might be, on the one hand, a biopsy needle
or, on the other hand, a canula, a trocar or a catheter adapted to
receive a needle by which the biopsy will be actually
performed.
[0018] To have a good transmission of optical information, an
optical fiber might be used. Said fiber might form a connection
between the console and the biopsy device, wherein the optical
fiber ends at the tip portion of the biopsy fiber and, thus, forms
the optical element.
[0019] The reflectance spectra of different types of tissue are in
general different due to the different molecular constitution of
the tissues. As a result of measuring these spectra, we are able to
identify different tissues from each other. The fact that the
optical method has only a limited penetration depth, the imaging
depth is only a few millimeters up to a few centimeters, guiding
the needle or canula without the guidance of the non-invasive
modality is difficult because there is no overview where the needle
or canula is in space. Furthermore, without being able to register
the optical information to the position of the biopsy device inside
the patient means that as soon as the device is moved the previous
measured data has lost its relevance.
[0020] Another aspect of the invention is that in translating the
measured optical data into a tissue type can be difficult when no
information about the surrounding morphology is known. Hence the
decision making of the tissue characterization improves having the
morphology information coming from the non-invasive imaging system
as input. Hence preferably first the optical data is registered to
the non-invasive imaging data, then the optical information
together with the morphology information around the needle coming
from the non-invasive imaging modality is used in translating the
measured optical data into a tissue type in front of or near the
needle. For instance when the needle is in soft tissue the optical
information can be affected whether a bone structure is close by or
not. Taking this into account a more reliable tissue
characterization is possible.
[0021] A method of positioning a biopsy device according to the
invention, comprises the steps of introducing the biopsy device
into a body, visualized by means of a non-invasive imaging system,
constituting a coarse guidance of the biopsy device, and fine
positioning the biopsy device assisted by an analyze device
comprising an optical element integrated in the biopsy device, and
a console for spectroscopy obtaining optical information
discriminating tissue in front of or near by the tip of the biopsy
device, constituting a fine guidance of the biopsy device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other objects of the present invention are
apparent from and will be elucidated with reference to the
embodiments described hereinafter and will reference to the
following drawings. The same or like elements are denoted by the
same reference signs throughout the drawing.
[0023] FIG. 1 shows a schematic drawing of taken a biopsy via the
rectum under ultrasound guidance.
[0024] FIG. 2 shows a schematic illustration of the system for
integrated guidance for positioning a biopsy device in a body,
according to an exemplary embodiment of the invention.
[0025] FIG. 3(A) shows an exemplary optical spectrum of diffuse
reflectance for a plurality of locations of a tip of a biopsy
device relative to an object. FIG. 3(B) shows a normalized spectrum
of diffuse reflectance of FIG. 3(A).
[0026] FIG. 4 shows an exemplary visualization of different
position of a biopsy device in a phantom, showing a fluoroscopic
X-ray image of the biopsy device together with the corresponding
optical reflectance spectrum (in the insert top left).
[0027] FIG. 5 shows a cross section of a biopsy device according to
an exemplary embodiment of the invention, in which the optical
fibers for guidance of biopsy and inspection of biopsy are located
in an hollow shaft of the biopsy device.
[0028] FIG. 6 shows schematically a set-up for Raman or
fluorescence spectroscopy.
[0029] FIG. 7 shows two types of fiber based needles.
[0030] FIG. 8 shows schematically an experimental setup for
measuring the optical spectra.
[0031] FIG. 9 shows another exemplary embodiment of a biopsy
device.
[0032] FIG. 10 shows exemplary boundaries of a tumor according to
different determination methods.
[0033] FIG. 11 shows absorption coefficients of different fluidic
substances.
[0034] FIG. 12 shows cross sectional views illustrating the
relation between the distance of a biopsy device according to an
embodiment of the invention, from a blood vessel and the absorption
spectrum visualized by the system according to an embodiment of the
invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0035] FIG. 2 shows a system according to an exemplary embodiment
of the invention. The system comprises an elongated biopsy device
200, an optical element 220 which is located at the tip portion of
the biopsy device, an imaging device 500 for assisting the coarse
guidance, an analyze device 20 for assisting the fine guidance, and
a computing device 600. The analyze device includes a light source
10 and a spectrograph 22. The imaging device 500 includes a
radiation source 510 and a detector array 520. The computing device
includes a processor unit 620 for processing the signals coming
from the imaging device 500 and from the analyze device 20, and a
monitor 610 for monitoring information for assisting the guidance
of the biopsy device in a body.
[0036] As illustrated in FIG. 2, a system for integrated guidance
for positioning a biopsy device in a body, comprises an image
guided X-ray based needle guidance system 500 (for instance a
system like XperGuide of Philips Medical Systems where
three-dimensional isotropic soft-tissue volumes are reconstructed
from rotational acquisitions and where live fluoroscopy is
co-registered with the 3D data set and superimposed on it.
Combining this with 3D road-mapping technique allows needle
guidance as described in "Live 3d Guidance in the Interventional
Radiology Suite", J. M. Racadio et al., Interventional radiology
ARJ 2007; 189:W357-W364) and a biopsy needle device 200 containing
an optical fiber, which is connected with an analyze device 20. The
image guided needle navigation system provides integrated 2D/3D
lesion imaging and an interactive image guided needle advancement
monitoring, all of which is coupled to the optical information
obtained by the needle, wherein the X-ray system 500 provides the
coarse guidance, while the optical information received from the
analyze device 20, provides the final precise guidance to the
biopsy location. Preferably, the X-ray data together with the
position of the needle is used as input for the optical
reconstruction of which tissue is in front of the needle.
[0037] Presented below is a short summary of the characteristics of
the first embodiment of the invention:
[0038] the system is able to interactively follow the biopsy needle
from the incision to the target point by superimposing 2D
fluro-image on 3D tissue reconstruction and provide molecular
tissue information at every point along the needle trajectory that
is registered to the position inside the body of the patient
[0039] the region along the needle trajectory can be scanned (scan
forward and scan aside) in order to provide indications on lesion
existence at the molecular level
[0040] preferably in reconstructing what tissue is in front of the
needle the X-ray data and the position information of the needle is
actively used in the optical reconstruction of what tissue is in
front of the needle
[0041] tumor boundaries deduced from needle scanning and from the
X-ray are compared. The X-ray information gives an estimate of the
shape of the tumor, but the exact boundary cannot be determined.
The needle gives detailed information of the tumor boundary but
this information is only obtained along the needle trajectory. By
combining the X-ray shape of the tumor with the one dimensional
information of the needle, a new estimate of the 3D tumor size can
be calculated (see third embodiment). The newly deduced enlarged
boundary will be a better estimate for the tumor boundary
[0042] X-ray and needle information is further coupled to MRI
images of the same area (MR data sets can be registered with the
data sets produced by the X-ray machine)
[0043] biopsy needle being equipped with an optical fiber is used
to position the localization wire. The localization wire containing
fixation means and may be equipped with a fiber.
[0044] To demonstrate the invention a needle intervention will be
described. The object from which the biopsy should be taken, is
placed on, for example, a C-arm bed and the needle is mounted on a
stepper motor that moves the needle in the axial direction (minimal
steps of 0.25 micron). The needle is connected with optical fibers
to a spectrometer. At least one of the fibers detects light
reflected from the tissue, hence is an optical element.
[0045] The needle intervention consists of acquiring X-ray and
fluoroscopic X-ray images while in addition optical reflectance
spectra are measured by the needle containing fibers coupled to a
console that is connected to the X-ray system.
[0046] After a full rotation of the C-arm around the object, it is
possible to generate 3D reconstructions of the object from the
X-ray information, including the position of the needle.
Furthermore, advancement of the needle can be done under
fluoroscopy X-ray imaging.
[0047] FIG. 3 shows an optical spectrum which might be achieved by
an analyze device for a plurality of locations of a tip of a needle
relative to an object. Said object might be a tube filled with
blood. The system according to the invention was utilized in a
phantom.
[0048] FIG. 3 shows the results, i.e. in FIG. 3(A) reflectance
versus wavelength for different distance between the tip of a
needle and a tube located in the phantom. Wherein the optical
spectrum is measured by a needle equipped with fibers. In FIG.
3(A), the vertical axis is `Reflectance` and the horizontal axis is
`Wavelength in nm`. FIG. 3(B) show the normalized reflectance with
respect to the signal when the needle is 32.5 mm away from the
tube. Here, the vertical axis is `normalized reflectance` and the
horizontal axis is `Wavelength in nm`.
[0049] FIG. 4 shows three illustrations which might be shown on a
monitor to assist in guiding a biopsy device. Each illustration is
mainly an image of an X-ray device, having added in the up left
corner an illustration of the spectrum achieved by the analyze
device. The fluoroscopy image of the X-ray device allows
determining the relative position of the needle (elongated black
line from the middle of each illustration to up right) with respect
to the phantom (dark shadow), while the spectral information
clearly shows when the small tube (black contrast line from up left
to down right) is approached. It allows to fine position the needle
within 100 micron accuracy. Although the information of the X-ray
image and the optical information are shown in a combined image,
there are various other ways to present the combined information
for instance by using colors.
[0050] FIG. 5 shows the tip portion of a biopsy device according to
an exemplary embodiment of the invention. The biopsy device 200
comprises a shaft 210 with a fiber bundle 220. Further, the shaft
210 is adapted to accommodate a needle 240 for taking a biopt.
Preferably, the fiber bundle 220 is located in the shaft 210 such
that the respective ends of the fibers are located in the end
surfaces of the tip portion of the biopsy device. In other words,
some of the fibers might end in the front surface of the biopsy
device, and/or some of the fibers might end in the vicinity of the
front surface at the side surface or wall surface of the biopsy
device. Furthermore, there could be some fiber ends orientated in
the direction to a biopt harvested by the biopsy device, and some
other fiber ends orientated in the direction to the front or the
side of the biopsy device, for optical guidance prior to biopsy. In
FIG. 5, fibers for optical guidance prior to biopsy are denoted
with reference sign 220a, and fibers for optical inspection of the
biopt are denoted with reference sign 220b.
[0051] It is noted, that any fiber might be used to emit and/or to
receive light.
[0052] FIG. 6 shows further components of the system. According to
this embodiment, some of the fibers 30 are coupled by way of a lens
52 to a light source 10 outside the body and are used for
excitation of the tissue in front of the shaft tip of the biopsy
device 100. Part of the scattered and emitted light is collected by
other fibers 40 and guided to a detector, via another lens 54,
which detector could be a spectrograph 22 coupled with a CCD-camera
24, where for instance an autofluorescence or Raman spectrum is
recorded. Upon inspection of the spectrum it is decided to either
take a biopsy with the biopsy device 100 or to move the shaft
further to another position if no anomalies in the spectrum are
found.
[0053] During the insertion of the biopsy device in the tissue,
spectra are recorded and linked to the position of the known X-ray
based needle guidance system.
[0054] For interpreting the spectra measured optically, hence
translating spectra into tissue properties, the X-ray data
(morphology) is used. For instance the X-ray data may provide
already an indication of what type of structure could be in front
of the needle, the optical data need than only to confirm or select
from a few possible candidate tissues. Checking what tissue matches
best with the measured spectra can then be done more reliably.
Another example is if we want to be inside a certain tissue. After
coarse guiding the needle with the X-ray system, the needle is fine
positioned until the measured optical spectra matches with the
targeted tissue.
[0055] In this way for various points information is obtained of
the tissue and is combined into the 3D image obtained by X-ray. The
coarse guidance to the diseased tissue is performed by the X-ray
images. The fine guidance is based on the optical information. When
the final location is reached a biopsy can be taken. Optionally,
the biopsy may be checked optically whether it contains the
diseased tissue.
[0056] A way to provide real-time tissue characterization is by
means of optical methods. For instance optical reflectance
spectroscopy or Raman spectroscopy are known to provide signatures
that are tissue specific. In the reflectance spectroscopy method
where tissue is illuminated with a broad band light source, the
reflected scattered spectral light distribution is measured. The
difference in tissue properties (i.e. difference in scattering
properties of the specific tissue) is visible in the changes of the
spectral light distribution compared to the original spectral
distribution of the illumination source. Furthermore, optical
spectroscopic imaging (i.e. extending the optical imaging from a
point measurement to two-dimensional imaging) provides even more
detailed tissue characterization. In this case tissue is viewed
with micron resolution allowing cellular structures to become
visible allowing detailed tissue analysis. When this cellular
imaging is combined with optical spectroscopy, tissue
characterization can be achieved, without using staining, that
comes close to what currently is being used in ex-vivo
pathology.
[0057] To make these methods available in a needle, the optical
fiber technology is employed. By integrating fibers into the
needle, optical probing at the tip of the distal end of the fiber
at the tip of the needle becomes possible. The analysis can then be
done at a console that is attached to the proximal end of the
fiber. The console is an integral part of the integrated navigation
system.
[0058] FIG. 7 shows two different types of fiber based needles. In
the first type (A) the fibers are rigidly integrated into the
needle, allowing spectroscopic analysis of the tissue near the
needle tip. Since the fibers are rigidly incorporated no cellular
imaging is possible. In the second type (B), a scanning fiber is
integrated into the needle. When a lens system is mounted in front
of the fiber a scanning confocal microscope is established allowing
microscopic imaging of tissue. In order to scan the fiber a motor
must be integrated in the needle, making the system more complex
than the fixed fiber.
[0059] There are various optical techniques that can be coupled to
these two ways of tissue inspection, wherein spectroscopy is one of
them. An example is optical reflectance spectroscopy. The
spectroscopic measurement on excised tissue is performed with the
needle equipped with optical fibers as is shown in FIG. 8. The
light source coupled to the fiber is a broadband light source. The
reflectance spectra are measured with a spectrometer and recorded
with, for example, a CCD-camera.
[0060] FIG. 9 shows a tip portion of a biopsy device according to
yet another embodiment of the invention, wherein the biopsy device
100 contains a collection of optical fibers. Although the
embodiment of a biopsy device in FIG. 9 does not have a lumen, it
can also be a device having a lumen. Each of the fiber entrance
positions at the base of the needle (for example in FIG. 9, the
positions indicated by numbers 101, 102 and 103) relates to a fiber
exit position at the head of the needle (in FIG. 9 indicated by
primed numbers 101', 102' and 103'). In this way the needle head is
covered with various optical probe positions, wherein the ends of
the respective fibers are orientated in the direction to the side
of the biopsy device.
[0061] Light is coupled by way of a lens 50 from fibers 30 into the
optical fibers at the base of the biopsy device, i.e. a needle, and
out of other optical fibers at the base of the biopsy device into
fibers 40. A light source 10, connected to an excitation fiber 30,
illuminates for instance fiber 101. The light will cross the fiber
and illuminate the tissue around exit position 101'. Light
scattering from this position can for instance reach position 102'
and 103'. The analyze device 20 is connected to fiber 40 that
collects the light coming from each fiber (101, 102 and 103
respectively). The intensity of the light is a measure for the
amount of absorption and scatter between exit position 101' and
102' and 103'. From these signals the tissue characteristics around
the needle can be extracted. It is worth noting that this
embodiment allows two-dimensional imaging of scattering and
absorption properties of the tissue surrounding the needle, with a
lateral resolution equal to that of the fiber-to-fiber distance.
Moreover, it is also possible to perform an optical coherence scan
for each fiber, which gives for each fiber a depth scan along a
line. Combining these lines, a three-dimensional image of the
tissue around the needle can be reconstructed, again with a lateral
resolution equal to that of the fiber-to-fiber distance.
[0062] A variation of this embodiment is the implementation of
fluorescence imaging and/or spectroscopic measurements. In this
case source 10 and fiber 30 serve as an excitation fiber, hence to
excite the fluorescent molecules and collection fiber to collect
the fluorescent light emitted by the molecules.
[0063] Similar as discussed in the first embodiment a Raman
spectroscopy can be performed, but now in principle for each fiber
end position 101', 102', etc.
[0064] Finally, it is also possible to perform diffuse optical
tomography (DOT) around the needle. This allows functional imaging
in a relatively large volume around the needle similar to what is
done in optical mammography. In this embodiment one or more fibers
are used for (sequential) illumination of the tissue. One or more
other fibers are used to collect the scattered light. Using an
image reconstruction algorithm it is possible to obtain a 3D map of
the optical properties in a region around the needle. The main
advantage of DOT is the high penetration depth compared to other
optical methods: about half of the source detector distance. The
most advantageous wavelength region for DOT is the near infrared
(NIR). Here the penetration depth is at its maximum and the optical
properties are strongly determined by important physiologic
parameters like blood content and oxygen saturation. By combining
DOT at different wavelengths it is possible to translate optical
parameters into physiological parameters.
[0065] The imaging methods mentioned above can rely on direct
absorption and scattering properties of the tissue under
investigation. However it is also possible to map fluorescence of
tissue, by illuminating with the proper wavelength and
simultaneously blocking the illumination wavelength at the detector
side. The fluorescence can be endogenous or exogenous, i.e. with
the aid of contrast agents. The specificity of the fluorescence
detection can be improved by methods well known in the art such as
fluorescence lifetime imaging.
[0066] According to a further aspect of the invention the tumor
boundaries might be deduced from needle information and said
information might be compared with information from the x-ray
system. In FIG. 10, the boundary 310 deduced from the optical
information (along a line 330 resulting in boundary points B and E)
is in general larger than the boundary 300 of the x-ray (resulting
in cross section points C and D with line 330) because of the
higher sensitivity of the method. The scale factor deduced from
this is used to extend the area according to that of the X-ray. The
newly deduced enlarged boundary 320 will be a better estimate for
the tumor boundary and can be used by the surgeon to plan an
intervention.
[0067] A further embodiment is where the invention is used to guide
the needle to the location of the suspicious tissue, but instead of
taking a biopsy the hollow needle is used to position a
localization wire. This localization wire is then used by the
surgeon to find the location of the tumor to be resected.
[0068] In a further embodiment the biopsy device may also be used
as a device for administering drugs or a therapy (like
percutaneously using RF, microwave or cryoablation) at a certain
position in the body without removing tissue, for instance for
injecting a fluid at the correct location of the affected body
part.
[0069] A further embodiment is for avoiding blood vessels.
[0070] By using a contrast enhanced (CE) CT acquisition, a 3D
reconstruction of both arterial and venous vessel tree will be
generated in addition to the soft tissue reconstruction of the
brain parenchyma. Both the soft tissue and the arterial/venous
vascularisation will be evaluated in order to find a location of
suspicious tissue. Using the XperGuide navigation software, the
needle trajectory will be defined as well as the needle advancement
monitored. The needle trajectory will be defined in such a way that
the planned path does not traverse any major vessel. Due to limited
accuracy of needle advancement (human error), additional feedback
on actual needle position with respect to the surrounding vessels
is required. This can be done by using optical spectroscopy to
measure the absorption properties of the tissue directly in front
of the needle tip by adding an optical fiber to the needle.
[0071] FIG. 11 shows absorption spectrums, wherein the vertical
axis means the absorption coefficient, and the horizontal axis
means the wavelength. In this exemplary diagram, the spectrum of
melanosome M, of Water W and of Blood HB is depicted. The
absorption spectrum of blood HB shows characteristic peaks in the
visible region around 400-600 nm. From the spectrum measured in
front of the biopsy needle the presence of blood can be deduced by
monitoring for these peaks in the absorption spectrum. This can be
done for instance by measuring the absorption at two wavelengths:
one within the absorption peak (for instance at 530 nm) and one
outside the peak (for instance at 633 nm). Taking the ratio of
these absorption values as blood vessel monitor signal, a blood
vessel will be approached when the signal significantly changes. In
this way it is not necessary to measure the absorption signal
absolutely, but only relatively.
[0072] Presented below is a short summary of the steps of a method
according to the invention:
[0073] determination of a suspicious tissue with diagnostic scans
(X-ray, CT, MRI),
[0074] 3D assessment of the arterial and venous vascular tree with
CE CT technique, establishment of the lesion access planning,
[0075] utilization of XperGuide to perform image guided monitoring
of needle advancing, according to the planning in (3),
[0076] depiction of blood carrying vessel structures in close
proximity of the needle tip with optical methods,
[0077] utilization of the optical information in order to re-adjust
needle direction in order to avoid the intervening vessel
structures.
[0078] The first embodiment is focused on items (1)-(4). The shaft
210 of the biopsy device 200 contains at least one fiber 220 and is
adapted to receive a needle 240 (see FIG. 12). The at least one
fiber is used to illuminate the tissue in front of the fiber and
also serves as collection fiber of the backscattered light. Part of
the scattered and emitted light, collected by the fiber is guided
to a spectrograph (see FIG. 6), where the absorption spectrum is
recorded 400, 410 (see FIG. 12). In case a blood vessel is far away
the absorption spectrum 400 does not reveal the absorptions peak
characteristic for blood (see FIG. 12(A)). However when a blood
vessel approaches the tip of the needle the absorption spectrum 410
will show the absorption peak for blood. Once such a signal shows
up the needle advances in changed direction such that the peak is
absent again.
[0079] There are various ways to measure or quantify this signal.
One way is to use two lasers sources one emitting at 550 nm and the
other at 633 nm. The signal relating to 550 nm probes the peak of
blood, while the signal related to 633 nm is rather insensitive.
Taking the ratio of these signals as triggering signal we are
insensitive for surroundings deviations.
[0080] The invention and its embodiments can be applied in various
clinical procedures, including: [0081] image guided brain biopsies,
[0082] image guided brain ablations, [0083] image guided brain
neuro-stimulations, [0084] guide the biopsy for cancer
diagnosis.
[0085] While the invention has been illustrated and described in
detail in the drawings and foregoing description, such illustration
and description are to be considered illustrative or exemplary and.
not restrictive; the invention is not limited to the disclosed
embodiments.
[0086] Other variations to the disclosed embodiments can be
understood and effected by those skilled in the art in practicing
the claimed invention, from a study of the drawings, the
disclosure, and the appended claims. In the claims, the word
"comprising" does not exclude other elements or steps, and the
indefinite article "a" or "an" does not exclude a plurality. The
mere fact that certain measures are recited in mutually different
dependent claims does not indicate that a combination of these
measured cannot be used to advantage. Any reference signs in the
claims should not be construed as limiting the scope.
LIST OF REFERENCE SIGNS
[0087] 10 light source [0088] 20 analyze device [0089] 22
spectrograph [0090] 24 CCD-camera [0091] 30 excitation fiber [0092]
40 collection fiber [0093] 50, 52, 54 lens [0094] 100, 200 biopsy
device [0095] 101, 102, 103 fiber entrance position [0096] 101',
102', 103' fiber exit position [0097] 210 shaft [0098] 220, 220a,
220b fiber [0099] 240 needle [0100] 300, 310, 320 boundary [0101]
330 optical information line [0102] 400, 410 absorption spectrum
[0103] 500 imaging device [0104] 510 X-ray source [0105] 520 X-ray
detector array [0106] 600 computing device [0107] 610 monitor
[0108] 620 processor unit
* * * * *