U.S. patent application number 12/601800 was filed with the patent office on 2010-10-21 for image formation apparatus and method for nuclear imaging.
This patent application is currently assigned to SURGICEYE GMBH. Invention is credited to Nassir Navab, Joerg Traub, Thomas Wendler.
Application Number | 20100266171 12/601800 |
Document ID | / |
Family ID | 39986366 |
Filed Date | 2010-10-21 |
United States Patent
Application |
20100266171 |
Kind Code |
A1 |
Wendler; Thomas ; et
al. |
October 21, 2010 |
IMAGE FORMATION APPARATUS AND METHOD FOR NUCLEAR IMAGING
Abstract
An image generating apparatus for image generation is provided.
The image generating apparatus includes a movable detector for
detecting nuclear radiation during a detection period and an
evaluation system. The evaluation system includes an interface
system for transmitting detector data to the evaluation system. The
detector data include information about the detected radiation for
image generation. The evaluation system further includes a data
memory portion for storing the detector data. The evaluation system
further includes a program memory portion with a program for
repeatedly determining at least one quality value with respect to
image generation during the detection period.
Inventors: |
Wendler; Thomas; (Munich,
DE) ; Navab; Nassir; (Munich, DE) ; Traub;
Joerg; (Munich, DE) |
Correspondence
Address: |
PATTERSON & SHERIDAN, L.L.P.
3040 POST OAK BOULEVARD, SUITE 1500
HOUSTON
TX
77056
US
|
Assignee: |
SURGICEYE GMBH
Munich
DE
|
Family ID: |
39986366 |
Appl. No.: |
12/601800 |
Filed: |
May 26, 2008 |
PCT Filed: |
May 26, 2008 |
PCT NO: |
PCT/EP2008/056433 |
371 Date: |
June 7, 2010 |
Current U.S.
Class: |
382/128 |
Current CPC
Class: |
G01T 1/161 20130101;
A61B 6/4258 20130101; A61B 6/5205 20130101; A61B 6/037
20130101 |
Class at
Publication: |
382/128 |
International
Class: |
G06T 7/00 20060101
G06T007/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 24, 2007 |
EP |
07010368.4 |
May 24, 2007 |
EP |
07010369.2 |
Claims
1-181. (canceled)
182. A method of image generation by an image generating apparatus,
comprising: detecting nuclear radiation by means of a movable
detector during a detection period; collecting detector data for
image generation by means of an evaluation system of the image
generating apparatus, wherein the detector data contain information
about the detected radiation; repeatedly determining at least one
quality value with respect to image generation from the collected
detector data by means of the evaluation system during the
detection period; and outputting an instruction to a user for
further moving the detector in dependence of the at least one
determined quality value, wherein the instruction relates to at
least a part of the remaining detection period.
183. The method according to claim 182, wherein the detector is
freely movable.
184. The method according to claim 182, wherein the detector is a
free-hand detector.
185. The method according to claim 182, further comprising:
continuously collecting detector data, for image generation, by
means of the evaluation system of the image generating apparatus
during the detection period.
186. The method according to claim 182, further comprising:
outputting the at least one determined quality value to a user.
187. The method according to claim 182, further comprising:
outputting an alert to a user if the at least one quality value
does not reach a threshold value.
188. The method according to claim 182, wherein outputting the
instruction to the user for further moving the radiation detector
comprises outputting of such a position and/or orientation of the
detector which, if adopted by the detector, would most enhance
image generation in relation to at least one quality value
according to a prognosis.
189. The method according to claim 182, wherein outputting the
instruction to the user and/or outputting the at least one
determined quality value to the user takes place on an output
system with at least one output unit in visual, acoustical, or
haptic form, or by combinations thereof.
190. The method according to claim 182, further comprising:
collecting body data by means of the evaluation system concerning
respiration and/or heart beat of a living being, optionally
comprising respiration frequency and heart beat frequency, and/or,
optionally, body data comprising form, position and/or orientation
of the body, wherein the body data with respect to respiration
and/or heart beat are optionally synchronized with the body data
with respect to form, position and/or orientation of the body; and
modifying an image generation rule on the basis of the collected
body data.
191. The method according to claim 182, further comprising:
tracking data of medical instruments by means of a tracking system,
and optionally generating an instrument image on the basis of the
collected instrument data by means of the evaluation system; and
guiding the user, while using the medical instruments, by means of
a guidance system on the basis of the instrument data.
192. An image generating apparatus for image generation,
comprising: a movable detector for detecting nuclear radiation
during a detection period; and an evaluation system comprising an
interface system for transmitting detector data with information on
the detected nuclear radiation for image generation to the
evaluation system, a data memory portion for storing the detector
data, and a program memory portion with a program for repeatedly
determining at least one quality value with respect to image
generation from the detector data during the detection period; and
wherein the image generating apparatus further comprises: an output
system comprising at least one output unit, wherein the at least
one output unit is an output unit for outputting an instruction to
a user for further moving the detector in dependence of the at
least one determined quality value, wherein the instruction relates
to at least a part of the remaining detection period.
193. The image generating apparatus of claim 192, wherein the
detector is freely movable.
194. The image generating apparatus of claim 192, wherein the
interface system is an interface system for continuously
transmitting, for image generation, detector data to the evaluation
system with information about the detected radiation and with
information about the position and/or orientation of the
detector.
195. The image generating apparatus of claim 192, wherein the at
least one output unit comprises one output unit for outputting of
the at least one determined quality value to a user and/or for
outputting an alert to a user if the at least one quality value
does not fulfill at least one quality criterion.
196. The image generating apparatus of claim 192, wherein the at
least one output unit comprises one output unit for outputting such
position and/or orientation of the detector that, if adopted by the
detector, would most enhance image generation in relation to at
least one quality value according to a prognosis.
197. The image generating apparatus of claim 192, further
comprising: a tracking system for gathering detector data about
position and/or orientation of the detector, wherein the tracking
system comprises: at least one sensor for gathering body data about
respiration and/or heart beat of a living being, optionally
comprising respiration frequency and/or heart beat frequency,
and/or, optionally a tracking unit for gathering body data of a
living being comprising form, position and/or orientation of the
body, and wherein the evaluation system further comprises: an
optional program memory portion with a program for collecting the
body data of the living being in synchronized manner, and a program
memory portion with a program for modifying an image generation
rule on the basis of the collected body data.
198. A method for image generation by means of an image generating
apparatus, comprising: detecting radiation by means of a freely
movable detector of the image generating apparatus during a
detection period; changing position and/or orientation of the
detector during the detection period; continuously collecting
detector data, for image generation, by means of an evaluation
system of the image generating apparatus during the detection
period, wherein the detector data comprise information about the
detected radiation and information about the position and/or
orientation of the detector; and determining at least one quality
value from the collected detector data by means of the evaluation
system.
199. The method according to claim 198, wherein the detector is a
free-hand detector.
200. An image generating apparatus for image generation,
comprising: a freely movable detector for detecting radiation
during a detection period; and an evaluation system, comprising: an
interface system for continuously transmitting detector data to the
evaluation system with information about the detected radiation and
with information about the position and/or orientation of the
detector for image generation during the detection period, a data
memory portion for storing detector data, and a program memory
portion with a program for determining at least one quality value
with respect to the image generation from the detector data.
201. The image generating apparatus according to claim 200, wherein
the detector is a freehand detector.
Description
[0001] The present invention relates to image generating
apparatuses and methods for image generation with image generating
apparatuses. Specific embodiments of the invention relate to image
generating apparatuses for enhanced image generation by means of
quality control, instruction to a user for data collection and/or a
continuous data collection with enhanced processing. Typical
embodiments of the present invention relate to image generating
apparatuses and methods for medical purposes.
BACKGROUND
[0002] High quality image generation is of great interest for a
vast area of applications. In particular, in the medical field
where the health of patient can depend thereon, the best possible
image generation is necessary, for example as a basis for surgery
on the patient.
[0003] Usually, medical images are generated either pre-operatively
or intra-operatively. Also a registration of images is known, for
example the registration of an anatomical image with a functional
image, i.e., an image that visualizes body activity. Such
registered images can for example help in tumor surgeries to decide
which body tissue is to be cut out. Images that are as up-to-date
and of as high quality as possible are desirable because in this
way it can be avoided to damage healthy tissue or not to remove
deceased tissue.
[0004] The generation of high quality images poses high demands on
detector data for image generation and on an evaluation system that
must process these data. This is particularly true for processing
of detector data with movable detectors which may for example be
hand-held.
[0005] Consequently there is a need for an enhanced collection and
evaluation of detector data and an enhanced image generation.
SUMMARY
[0006] In light of the above, a method for image generation
according to claims 1 to 92 and an image generating apparatus
according to claims 93 to 181 are provided.
[0007] According to one embodiment of the invention, an image
generating apparatus for image generation is provided. The image
generating apparatus includes a movable detector for detecting
nuclear radiation during a detection period. The image generating
apparatus further includes an evaluation system. The evaluation
system includes an interface system for transmitting detector data
to the evaluation system. The detector data include information
about the detected nuclear radiation for image generation. The
evaluation system further includes a data memory portion for
storing the detector data. The evaluation system further includes a
program memory portion with a program for repeatedly determining at
least one quality value with respect to image generation from the
detector data during the detection period.
[0008] According to a further embodiment of the present invention
an image generating apparatus for image generation is provided. The
image generating apparatus includes a freely movable detector for
detecting radiation during a detection period. The image generating
apparatus further includes an evaluation system. The evaluation
system includes an interface system for continuously transmitting
detector data to the evaluation system during the detection period.
The detector data include information about the detected radiation
and information about the position and/or orientation of the
detector for image generation. The evaluation system further
includes a data memory portion for storing the detector data and a
program memory portion with a program for determining at least one
quality value with respect to the image generation from the
detector data.
[0009] According to a further embodiment of the invention, an image
generating apparatus for image generation is provided. The image
generating apparatus includes a freely movable detector for
detection of radiation during a detection period. The image
generating apparatus further includes an evaluation system. The
evaluation system includes an interface system for continuously
transmitting detector data for image generation during a detection
period. The detector data include information about the detected
radiation. The detector data further include information about the
position and/or orientation of the detector. The evaluation system
further includes a data memory portion for storing detector data.
The evaluation system further includes a program memory portion
with a program for determining at least one quality value with
respect to image generation from the detector data.
[0010] According to a further embodiment of the invention, an image
generating apparatus for image generation is provided. The image
generating apparatus includes a movable detector for detecting
radiation. The image generating apparatus further includes an
evaluation system. The evaluation system includes an interface
system for transmitting detector data for image generation to the
evaluation system. The detector data include information about the
detected radiation. The detector data further include information
about the position and/or orientation of the detector. The
evaluation system further includes a data memory portion for
storing detector data. The evaluation system further includes a
program memory portion with a program for determining an image
generation rule for image generation on the basis of the collected
detector data, taking into account a detection model. The detection
model takes into account a material property of a material
influencing the detection and/or a constraint.
[0011] According to a further embodiment, an image generating
apparatus for image generation is provided. The image generating
apparatus includes a movable detector for detection of radiation.
The image generating apparatus further includes an evaluation
system. The evaluation system includes an interface system for
transmitting detector data for image generation to the evaluation
system. The evaluation system further comprises a program memory
portion with a program for registering detector data with
compatible data.
[0012] According to a further embodiment, an image generating
apparatus for image generation is provided. The image generating
apparatus includes a movable detector for detection of nuclear
radiation during a detection period. The image generating apparatus
further includes an evaluation system. The evaluation system
includes an interface system for transmitting detector data for
image generation to the evaluation system. The detector data
include information about the detected nuclear radiation. The
evaluation system further includes a data memory portion for
storing detector data. The evaluation system further includes a
program memory portion with a program for determining an image
generation rule on the basis of the collected detector data. The
evaluation system further includes a program memory portion with a
program for repeatedly modifying the image generation rule on the
basis of at least one quality value during the detection
period.
[0013] According to a further embodiment, a method for image
generation by means of an image generating apparatus is provided.
The method includes detecting nuclear radiation by means of a
movable detector during a detection period. The method further
includes collecting detector data for image generation by means of
an evaluation system of the image generating apparatus. The
detector data include information about the detected radiation. The
method further includes repeatedly determining at least one quality
value from the collected detector data by means of the evaluation
system during the detection period and outputting an instruction to
a user for further moving the detector in dependence of the
collected detector data and/or of the at least one determined
quality value, wherein the instruction relates to at least a part
of the remaining detection period.
[0014] According to a further embodiment a method for image
generation by means of an image generating apparatus is provided.
The method includes detecting radiation by means of a freely
movable detector of the image generating apparatus during a
detection period, and changing position and/or orientation of the
detector during the detection period. The method further includes
continuously collecting detector data for image generation by means
of an evaluation system of the image generating apparatus during
the detection period. The detector data include information about
the detected radiation and information about the position and/or
orientation of the detector. The method further includes
determining at least one quality value from the collected detector
data by means of the evaluation system.
[0015] According to a further embodiment, a method for image
generation by means of an image generating apparatus is provided.
The method includes detecting radiation by means of a movable
detector of the image generating apparatus during a detection
period. The method further includes changing the position and/or
orientation of the detector during the detection period. The method
further includes continuously collecting detector data for image
generation by means of an evaluation system of the image generating
apparatus during the detection period. The detector data include
information about the detected radiation. The detector data further
include information about the position and/or orientation of the
detector. The method further includes determining at least one
quality value from the collected detector data by means of the
evaluation system.
[0016] According to a further embodiment, a method for image
generation by means of an image generating apparatus is provided.
The method includes detecting radiation by means of a detector of
the image generating apparatus. The method further includes
collecting detector data for image generation by means of an
evaluation system of the image generating apparatus. The detector
data include information about the detected radiation. The detector
data further include information about the position and/or
orientation of the detector. The method further includes
determining an image generation rule by means of the evaluation
system for image generation on the basis of the collected detector
data, taking into account a detection model. The detection model
takes into account a material property of a material influencing
the detection and/or a constraint.
[0017] According to a further embodiment, a method for image
generation by means of an image generating apparatus is provided.
The method includes detecting radiation by means of a detector of
the image generating apparatus. The method further includes
collecting detector data of the detector for image generation by
means of the evaluation system of the image generating apparatus.
The method further includes registering the detector data with
compatible data by means of the evaluation system.
[0018] According to a further embodiment, a method for image
generation by means of an image generating apparatus is provided.
The method includes detecting nuclear radiation by a movable
detector of the image generating apparatus during a detection
period. The method further includes collecting detector data for
image generation by means of an evaluation system of the image
generating apparatus. The detector data include information about
the detected radiation. The method further includes determining an
image generation rule by means of the evaluation system on the
basis of the collected detector data. The method further includes
repeatedly modifying the image generation rule on the basis of at
least one quality value during the detection period.
[0019] Further features, aspects, and details which can be combined
with embodiments described herein are disclosed in the dependent
claims, the description and the drawings.
SHORT DESCRIPTION OF THE FIGURES
[0020] So that the above features can be better understood in
detail, a more specific description is given with reference to
embodiments of the invention. The appended drawings relate to
embodiments of the invention and will be described shortly in the
following.
[0021] FIG. 1 shows a schematic arrangement of an image generating
apparatus according to embodiments of the invention;
[0022] FIG. 2 shows a detector system of the image generating
apparatus according to embodiments of the invention;
[0023] FIG. 3 shows a detection system of the image generating
apparatus according to embodiments of the invention;
[0024] FIG. 4 shows a schematic arrangement of an evaluation system
of the image generating apparatus according to embodiments of the
invention;
[0025] FIG. 5 shows a schematic arrangement of program memory
portions of the evaluation system according to embodiments of the
invention;
[0026] FIG. 6 shows an output system of the image generating
apparatus according to embodiments of the invention;
[0027] FIG. 7 shows a further output system of the image generating
apparatus according to embodiments of the invention;
[0028] FIG. 8 shows a guiding system of the image generating
apparatus according to embodiments of the invention;
[0029] FIG. 9 shows an image generating apparatus according to
embodiments of the invention at use in the medical field;
[0030] FIG. 10 shows the generation of a detection model according
to embodiments of the invention;
[0031] FIG. 11 shows the generation of a detection model via
measurements according to embodiments of the invention;
[0032] FIG. 12 shows a quality control process according to
embodiments of the invention;
[0033] FIG. 13 shows an iterative flow diagram with a step of
instructing a user according to embodiments of the invention;
[0034] FIG. 14 shows a detection process with a freely movable
detector according to embodiments of the invention.
DETAILED DESCRIPTION
[0035] In the following detailed reference is made to various
embodiments of the invention, of which some are exemplarily
illustrated by the drawings. Each example is provided by means of
explanation and for a better understanding of the invention and
shall not be construed as limiting the invention. Thus, features
which are described with respect to one embodiment, or are being
illustrated with respect to one embodiment, can be combined with
other embodiments to generate further embodiments. It is intended
that such modifications and variations are encompassed.
[0036] In particular, embodiments of the invention are mostly
described, for a better understanding, with respect to image
generation for medical purposes. However, many of the embodiments
can also be used for image generation in other fields.
[0037] Within the following description and in the drawings the
same reference signs relate to the same or similar components.
Generally, only the differences between individual embodiments are
explicitly described.
[0038] The expression "detection period" used herein denotes a
period between the beginning of a first detection process and the
end of last detection process. The first and last detection process
can be identical such that the detection period is a period during
which a detection process continuously takes place. The first and
last detection can also be different. In a detection period other
processes can therefore lie. For example, such other processes can
be data evaluation processes. The at least one detection process
taking place in the detection period is carried out by the same
detector, respectively detector system, on the same object. An
example for a detection period is the period between the first
measurement of nuclear radiation with a gamma probe on a patient
and the last measurement, wherein for example after the last
measurement a final image with the visualization of body functions
can be generated. Between the first measurement and the last
measurement there can also be one or several measurement pauses,
for example for data evaluation or even for measurement on another
object. A detection period would for example not be defined by a
first measurement only on the back of a patient and by a further
measurement only on the stomach of the patient.
[0039] Specifying that an action is carried out "during a detection
period" (or more generally during any period) is not to be
construed in the sense that the action needs to fill the full
period. The action can also only take place during part of the
detection period. The action can also be interrupted.
[0040] The expression "freely movable" is generally understood in
that the position and/or orientation of an object which is freely
movable can be changed substantially arbitrarily. For example, a
detector which is handheld is a freely movable detector. Also, a
detector which is mounted to a robot arm with sufficiently many
degrees of freedom is freely movable, wherein the robot arm is for
example controlled by a user. A detector which is movable along a
rail is movable but not freely movable.
[0041] The expression "continuous" includes, when relating to an
action such as "continuously collecting detector data", an ongoing
or regularly repeated action. The temporal distances between the
regular repetitions can in principally in principal be arbitrarily
short, i.e. quasi-continuous. However, it is obvious for the
skilled person that, for example, physical constraints can limit
arbitrarily short distances. For example, detectors can have
so-called "dead times" such that during such dead times no
detection can take place. Consequently, also during e.g. a
continuous collection of the detector data, a regular repetition of
data collection within the collection process may not be possible
within time intervals that are shorter than said dead times. The
notion "continuous" includes, when used in relation to an action,
also the repetition or the iterated repetition in arbitrarily short
time intervals. Also arbitrarily selected time intervals can, in
principle, be arbitrarily shortly following each other, and
limitations as explained above apply analogously.
[0042] The "generation of an image" includes the generation of
image data without the need for output of such image data to an
output unit, for example a monitor.
[0043] FIG. 1 shows an image generating apparatus 1 according to
embodiments of the invention. As shown in FIG. 1, the image
generating apparatus 1 includes a detector system 100. The detector
system 100 includes at least one detector 110. The image generating
apparatus further includes an evaluation system 300. The evaluation
system 300 includes at least one memory unit 310 and at least one
processing unit 350. In some embodiments the detector system and
the evaluation system are linked by a data exchange system 20.
According to further embodiments, the image generating apparatus
includes a tracking system 200 as shown in FIG. 1. The tracking
system 200 includes at least one tracking unit 210. In further
embodiments the image generating apparatus includes an output
system 400. The output system includes at least one output unit
410. In some embodiments, the tracking system 200 and the output
system 400 are connected to the evaluation system 300 by means of a
data exchange system. In further embodiments the image generating
apparatus includes a guiding system 500. The guiding system 500
includes at least one guiding unit 510. The guiding system can be
connected to the evaluation system by means of a data exchange
system. The individual systems are described in more detail in the
following.
Detector System 100
[0044] According to embodiments of the invention, the detector
system 100 includes a detector 110. In typical embodiments, the
detector 110 is a radiation detector, typically a detector for
nuclear radiation. According to some embodiments the detector is
movable, according to specific embodiments even freely movable. In
typical embodiments the detector is handheld. The detector can be a
gamma radiation probe, a beta radiation probe, a Compton probe, a
gamma radiation camera, a gamma radiation mini camera, a beta
radiation camera or a Compton camera. The detector can also be a
detector for optical radiation, a detector for infrared radiation,
x-rays or a detector for other kinds of radiation or any other kind
of detector.
[0045] Detector data can include information about the detected
radiation. The detector data can be formatted to a certain degree
but generally the association of single data sets to specific
detection events or at least to a group of detection events should
be possible. The detector data can also include position and/or
orientation of the detector. Detector data can further include
other data.
[0046] In some embodiments, the detector system 100 includes at
least one further detector. The at least one further detector can
be similar to the detector 110 or identical in built. The at least
one further detector can also be of a different kind as compared to
detector 110. The at least one further detector can, for example,
be an ultrasonic probe, an x-ray detector, an optical camera, an
optical microscope, a fluorescence camera, an auto-fluorescence
camera, a magnetic resonance tomography detector, a positron
emission tomography detector, short PET, a single photon emission
computer tomography detector, short SPECT, or another kind of
detector.
[0047] FIG. 2 shows a detector system 100 according to embodiments
of the present invention. In FIG. 2, two detectors 110, 120 of the
detector system 100 are shown: a probe 110 for detecting nuclear
radiation and an optical camera 120. The nuclear radiation can for
example be gamma, beta, Compton, x-ray, or alpha radiation.
Further, a nuclear radiation source 10 that is to be detected is
shown. A radiation source can generally be, here and in the
following, a spatially distributed radiation source, i.e. a spatial
radiation distribution. A radiation source can also be a
substantially two dimensional radiation source, i.e. a radiation
distribution that is substantially plane.
[0048] The detectors can be handheld as shown and be movable and
orientable in the three spatial directions, i.e. freely movable.
Further, the detectors 110, 120 each have a cable for power supply
and for data exchange, e.g. with the evaluation system 300 shown in
FIG. 1. Further, the detectors 110, 120 each have markings for
tracking by the tracking system 200 shown in FIG. 3, as further
described below with respect to FIG. 3. There can also be a
tracking system 200 that works without markings.
[0049] Detector data, such as detector data with information about
measured radiation, can be provided to the evaluation system 300
(see FIG. 1). In particular, the evaluation system 300 can collect
the detector data.
Tracking System 200
[0050] According to some embodiments, the image generating
apparatus includes a tracking system 200. According to some
embodiments, the tracking system 200 includes a tracking unit 210.
The tracking unit can be an optical, electromagnetic, mechanical,
robot-based, radio wave-based, sound wave-based, goniometer-based,
potentiometer-based, gyroscope-based, acceleration sensor-based,
radiation-based, or x-ray-based detection unit, or an infrared or
white light detection unit or another kind of detection or tracking
unit. According to further embodiments, the tracking system 200
includes a further tracking unit 220 or further tracking units. The
tracking unit 220 or the further tracking units can be tracking
units as the ones listed above or can be other tracking units. To
guarantee feasibility or reliability of the tracking system, some
embodiments have at least two, at least three or at least four
tracking units.
[0051] FIG. 3 shows a tracking system 200 according to typical
embodiments of the present invention. FIG. 3 shows two optical
tracking units 210 and 220. The optical tracking units 210 and 220
detect markings 112 on the probe of nuclear radiation 110 and
markings 122 on the optical camera 120. The optical tracking units
210 and 220 generate, by detecting the markings 112 and 122, data
with information about the position and/or orientation of the probe
110 and the camera 120. In the example shown in FIG. 3, the optical
tracking units 210 and 220 are exactly calibrated, and the position
and orientation of probe 110 and of the camera 120 is being
determined by detecting the position of the markings 112, and 122
respectively, by means of known triangulation methods.
[0052] Data of the tracking systems, such as detector data with
information about the position and orientation, can be provided to
the evaluation system 300. In particular, the evaluation system 300
can collect such and other detector data.
Evaluation System 300
[0053] According to embodiments of the present invention, the
evaluation system 300 includes a memory system 302 with a memory
unit 310. The memory unit 310 can for example be a computer hard
drive or another mass storage device, or can be of a different
kind. According to embodiments of the invention, the storage unit
310 includes a data storage portion 320. The data storage portion
320 can for example be used for storing detector data. The data
storage portion 320 can also be used for storing other data.
According to embodiments, the storage unit 310 includes a program
storage portion 330. The program storage portion 330 as well as
further program storage portions according to further embodiments
will be described further below. The data storage unit 310 can
include further data storage portions and further program storage
portions. The different storage portions need not physically or in
a memory-technical sense form a unit; different portions are rather
distinguished only with respect to the nature of the data stored or
to be stored therein. The memory system 302 can include further
memory units. The further memory units can be similar to memory
unit 410 or of a different kind.
[0054] According to further embodiments, the evaluation system 300
includes a processing system 304. The processing system 304
includes a processing unit 350 according to some embodiments. The
processing unit 350 can for example be the computing part of a
computer, for example a processor. According to further embodiments
the processing system 304 includes further processing units, which
can be similar to the processing unit 350 or be of a different
kind. In particular, at least one processing unit and at least one
memory unit can be integrated in special devices, such as
commercially available computers.
[0055] According to further embodiments, the evaluation system
includes an interface system 306. In some embodiments the interface
system 306 includes a detector system interface 306a with a
detector interface 380 for data exchange with a detector, for
example with the detector 110. In further embodiments the interface
system 306 includes a tracking system interface 306b with a
tracking unit interface 390 for data exchange with a tracking
system (for example, the tracking system 200 of FIG. 3). An
interface system 306 or parts thereof can also be integrated in
special devices, such as commercially available computers. In some
embodiments, the evaluation system communicates with other partial
systems of the image generating apparatus via such interface
systems by means of a data exchange system.
[0056] In further embodiments of the invention, the program memory
portion 330 includes a program. As shown in FIG. 5, the program can
for example be a program 330 for determining at least one quality
value on the basis of detector data. In other embodiments, a memory
unit includes further program memory portions, for example further
program memory portions 332 and 334 with program 332a for
determining an image generation rule on the basis of detector data
while taking into account a detection model, and respectively with
a program 334a. Program 334a includes program part 334b for
determining at least one quality value on the basis of detector
data and program part 334c for repeatedly determining at least one
quality value on the basis of detector data.
[0057] In particular, programs, which for example carry out similar
functions, can also be formed as program parts of a single program,
as for example described above for program 334a. The same is also
true for functionally different programs. In both cases, the first
program portion with a first program and a second program portion
with a second program are identical, and the first and second
program are considered as parts of a single program.
[0058] In further embodiments, in which a first program portion
with a first program and a second program portion with a second
program are provided, the first program portion can be identical to
the second program portion as well as the first program to the
second.
Output System 400
[0059] With reference to FIG. 6, the image generating apparatus
includes an output system 400 according to further embodiments. The
output system 400 includes an output unit 410 according to some
embodiments. The output unit 410 can be a visual, acoustical or
haptic output unit or a combination form thereof. In some
embodiments, the output unit 410 is an output unit for displaying
images or an instruction to a user. A user is usually a human
being. Alternatively, a user can also be a different living being
or an inanimate object, for example a machine.
[0060] In further embodiments, the output system 400 includes
further output units. These can be of similar kind as the output
unit 410 or of a different kind.
[0061] Output units according to embodiments of the present
invention can display reality, display a virtual reality or display
an augmented reality. An output unit of an augmented reality can
for example combine a real image with virtual images.
[0062] According to embodiments of the invention, an output unit
can, among others, be one of the following: monitor, optically
transparent monitor, stereo monitor, head-mounted stereo displays,
acoustical frequency-coded feedback systems, acoustical pulse-coded
feedback systems, force-feedback joysticks or force-torque-feedback
joysticks or other kinds of visual, acoustical and/or haptic output
units or combinations thereof.
[0063] FIG. 6 shows an output unit 410 according to embodiments of
the present invention. In FIG. 6, the output unit 410 is an optical
output unit, in particular a monitor. FIG. 6 shows further an
acoustical output unit 420. In FIG. 6, the acoustical output unit
is a loudspeaker.
[0064] FIG. 7 shows a further output unit 430 in form of a
head-mounted visual display.
Guiding System 500
[0065] In further embodiments, the image generating apparatus
includes a guiding system 500, as for example shown in FIG. 8.
According to some embodiments, the guidance system 500 includes a
guiding unit 510. A guiding unit 510 can for example guide an
object by means of a robot arm. The guiding unit 510 can also guide
a user. Guiding can also be robot-based or else can rely upon
optical, acoustical or haptic signals or on combinations thereof.
The guiding unit 510 shown in FIG. 8 guides the user by haptic
signals. In FIG. 8, the guiding unit 510 serves for better guiding
a surgical instrument 40 during surgery on a body 30. The guiding
unit may for example provide a resistance, be it by mechanical
hindrance or by stimulation of the muscles by means of electrical
pulses.
[0066] The guiding unit 510, or further guiding units, can also be
formed by output units of the output system if the guidance of the
user is effected by a corresponding output. The guiding system 500
can therefore be identical with the output system 400.
[0067] In further embodiments, the image generating apparatus
includes a data exchange system. As shown in FIG. 1, the data
exchange system serves for exchanging data between systems of the
image generating apparatus, for example for exchange of data
between detector system and evaluation system, between tracking
system and evaluation system, between output system and evaluation
system, or between guiding system and evaluation system (as shown
in FIG. 1 by means of corresponding connection lines). The data
exchange system can rely upon interfaces such as the detector
interface 380 or the tracking system interface 390, according to
some embodiments. Generally, the exchange of data can take place by
a connection of the systems by means of cables or else wireless or
in any other way.
[0068] FIG. 9 shows, according to embodiments of the invention, a
body part of a human or other living being, into which radioactive
substances have been injected, so-called tracers, which accumulate
in certain preferred regions and are stuck there. The regions or
spatial areas in which the radioactive substances are accumulated,
respectively are stuck, can be regarded as closed regions which
include a source of nuclear radiation.
[0069] FIG. 9 further shows a detector for nuclear radiation 110.
The detector 110 measures the nuclear radiation that emerges from
the source within the body. Further, FIG. 9 shows a laparoscope 120
which gathers data for generating an optical image of the interior
of the body. The data gathered by the detector for nuclear
radiation 110 and the laparoscope 120 are collected in the
evaluation system (not shown) and are processed. Further, the
position and/or orientations of the two detectors are tracked via
markings 112 and 122, and corresponding data is collected by the
evaluation system. From all these data, the evaluation system
generates, with the help of an image generation rule, an optical
image of the interior of the body based on data of the laparoscope
as well as a functional image, that visualizes body functions such
as metabolism, based on the data of the detector for nuclear
radiation. The image can in particular be three dimensional.
[0070] On an output unit 410, the optical anatomic image and the
functional image are overlaid and, for example, displayed three
dimensionally. The overlay is generated on the basis of a
registration of the optical image with the anatomic image by means
of the evaluation system.
[0071] Further, FIG. 9 shows a surgical instrument 40 the position
and/or orientation of which are also tracked. The gathered data of
the surgical instrument are also processed by the evaluation
system. In this way, an image of the surgical instruments and of
their location in the interior of the body can be determined by the
evaluation unit. This image can also be registered with the
anatomic and optical image and be displayed on the output unit 410.
If, in particular, the functional image is high quality and
up-to-date and if the registration with the optical image and the
instrument image is good, the output of the registered images on
the output unit enables a surgeon to precisely control the
surgery.
[0072] The images of known image generating apparatuses and of
corresponding methods for image generation are, however, oftentimes
images used in surgery, but which are not up-to-date.
[0073] This applies for example to pre-operative images, since the
taking of which the tissue and its functions may already have
undergone change. If intra-operative images are used, problems
oftentimes result in particular when using movable detectors,
because then known evaluation systems are not capable of
guaranteeing a high quality image. To enhance image generation
there is a need of quality control, in particular a quality control
already during the gathering of detector data. Such quality control
can also be a continuous quality control. Further, for enhancing
image generation, an enhanced data set is desirable, which can be
insured by giving instructions for detection. In particular, with
movable or even handheld detectors, the gathering of detector data
which can in principle take place at any moment and with any
arbitrary position and/or orientation of the detector, poses a
challenge. For enhancing image generation, it is further desirable
to use existing information, for example about anatomic facts,
detector properties, other material properties which may influence
the detection, or about constraints. Also an enhancement of
registration of the images can contribute to enhance image
generation. Changing an enhancing the imaging rule already during
the detection period can also enhance image generation overall.
[0074] According to embodiments of the invention, means for
enhancing image generation are provided.
Collecting Detector Data
[0075] According to embodiments of the present invention, detector
data are collected by the evaluation system. Therein, position
and/or orientation of the detector can have been tracked by a
tracking system. The detector data include information about the
detected nuclear radiation, according to some embodiments. In
further embodiments, the detector data include information about
the position and/or orientation of the detector. For example, data
with information about the detected radiation can be synchronized
with data about the position and/or orientation of the detector and
be collected in synchronized form. With respect to synchronization
of data, see WO 2007/131561, in particular page 3, lines 1 to 6 and
lines 27 to 32, and page 6, lines 22 to 30, in corporate herein by
reference. The WO 2007/131561 is further included herein by
reference in its entirety. In further embodiments, the detector
data are stored in the evaluation system.
[0076] In further embodiments, a detector detects radiation during
a detection period. This radiation can be radioactive, respectively
nuclear radiation. Nuclear radiation is also to be understood as
radiation which is indirectly generated by radioactive decays, for
example ionization radiation of an alpha particle. Embodiments of
the invention in which the detector measures nuclear radiation
hence also include detecting of such secondary radiation.
Image Generation and Image Generation Rule
[0077] In further embodiments, the evaluation system generates an
image from the detector data by means of an image generation rule.
In typical embodiments, this image is an image of the radiation
distribution and thus of the radiation sources in a spatial
region.
[0078] According to further embodiments, the image generation rule
is a linear rule. Therein, an imaging matrix H, also called system
matrix, is typically applied to a vector f=(f.sub.1, f.sub.2, . . .
f.sub.N). The vector f contains image information. Typically, for
visualizing an image of a spatial region, this spatial region is
divided into image elements (voxel). Each index i=1, 2, . . . , N
of the vector f is then associated with a particular image element.
Information elements with respect to these image elements (for
example the intensity of radiation in the corresponding image
element) form the entries f.sub.i of the vector f to a
corresponding index i.
[0079] The detector data are also collected in a vector g=(g.sub.1,
g.sub.2, . . . ). Each index k=1, . . . , M is thereby associated
to a measurement (or an averaged series of measurements, see below)
of a detector, and the entry g.sub.k contains the result of the
intensity of radiation measured during this measurement.
[0080] The entries H.sub.ki of the imaging matrix H model the
influence of a normalized radiation source at the position
belonging to the index i onto the k.sup.th measurement. The imaging
matrix H contains, in its entries H.sub.ki, information about
positions and orientations of the detector for nuclear radiation.
As the different contributions linearly superpose, a result of the
measurement with a radiation distribution f.sub.i is to be expected
which is approximately given by the vector
g_predicted.sub.k=.SIGMA..sub.iH.sub.kif.sub.i. In matrix notation
(with "*" as matrix product):
g_predicted=H*f
Such a vector g_predicted can be compared to a vector g_measured
which contains the actual detector data with information about the
detected radiation. In this comparison, different measurement
errors, for example contributions of external radiation sources,
imperfections of the detector, statistical errors, etc. are to be
taken into account.
[0081] The image generation can now be described in a way that a
vector f with data information regarding the radiation distribution
in a spatial region shall be found that best corresponds to the
actually measured data about the nuclear radiation. For this, a
conceptual ansatz is the minimization of the distance
|H*f-g_measured|,
over all estimated radiation distributions the image information of
which is coded into a respective vector f. Therein, |.cndot.|
denotes a suitable distance norm. In typical embodiments, |.cndot.|
is computed as the L.sub.2 norm. This minimization can also be
implemented as an iterative process. The involved minimization
process can be carried out for example by algebraic reconstruction
techniques, maximum likelihood expectation value maximization,
pseudo inversion by means of singular value decomposition,
Gauss-Seidel inversion, successive over-relaxation, Jacobi
inversion, multiplicative algebraic reconstruction techniques,
simultaneous iterative reconstruction techniques or by other
techniques. Also, regularization methods such as Tikhonov
regularization, total variation regularization and other
regularizations can be used. In light of this, the image generation
rule is defined, in the first line, by the matrix H. But, also the
algorithm to be used for solving the minimization problem as well
as the starting vector to be used in an iterative solution are part
of the image generation rule.
[0082] In further embodiments, the image generation rule is
non-linear. Also for such a non-linear image generation rules,
analogous methods can be applied.
Detection Models
[0083] According to embodiments, image generation rules, in
particular the matrix H described above can be generated or
enhanced on the basis of at least one detection model. Detection
models can be changed or adapted, in particular on the basis of new
detector data. According to some embodiments, detection models can
be enhanced or be continuously enhanced. Enhanced or continuously
enhanced detection models can be used for enhancing an image
generation rule.
[0084] With a linear image generation rule according to embodiments
of the present invention the entries of the imaging matrix can be
calculated with the help of detection models. Such detection models
can be generated by algebraic, analytic, numeric, or statistical
methods, or on the basis of measurement data or by combinations
thereof. In some embodiments, detection models are generated by
measurements on a radioactive point source which is positioned
differently and the radiation of which is measured from different
positions and orientations. By such measurements or by suitable
detection models, information is gained about for example at least
one material property of at least one material, or such information
is used. In the case of image generation for medical purposes,
material properties of materials distributed in space can be
determined, such as operation table, instruments, but also the
patient himself.
[0085] Material properties include the attenuation between source
and detector, the scattering between source and detector, the
material properties of materials between source and detector, the
attenuation by a detector shield or the scattering by a detector
shield, the attenuation in the detector itself and the scattering
in the detector itself.
[0086] Further, analytic, algebraic, numerical, or statistical
models, or models that are combinations thereof, can also take into
account constraints besides material properties. Examples for
constraints are the relative solid angle between a detector and a
source area of radiation, the dimensions of the detector or the
absence of material or matter. Constraints allow to exclude certain
image vectors f from the start, and to thereby obtain better
results of the optimization problems described above.
[0087] FIG. 10 schematically shows the mapping of real objects and
of a real detection process onto a detection model and a simulated
detection process. According to embodiments of the invention, real
objects such as a detector 110, a body 30 and a source of radiation
10 within the body are mapped to data of a detection model.
Therein, data with respect to a detector describe a virtual
detector 110a, data with respect to the body describe a virtual
body 30a, and data with respect to the radiation source describe a
virtual radiation source 10a.
[0088] FIG. 11 illustrates the determination of a detection model
on the basis of measurements. A radioactive point source 50 emits
nuclear radiation 52 in all spatial directions. A detector 110
measures the radiation source 50 at different positions and with
different orientations (second position/orientation is depicted
with dashed lines), whereby information about material properties
are gained. Material properties can for example include those of
the body 30. From the measurement data, a detection model can be
determined. The detection model can take into account the
information of the measurement data and further information, such
as for example the detector geometry.
[0089] According to embodiments of the present invention, a method
for image generation by means of an image generating apparatus is
provided. The method includes detecting radiation by means of a
detector of the image generating apparatus. The radiation may be
nuclear radiation. Detecting can take place during a detection
period. The method further includes collecting detector data for
image generation by means of an evaluation system of the image
generating apparatus. In typical embodiments, the detector data
include information about the detected radiation. In further
typical embodiments, the detector data include information about
the position and/or orientation of the detector. The method further
includes determining an image generation rule by means of the
evaluation system for image generation on the basis of the
collected detector data, taking into account a detection model. In
typical embodiments, the detection model takes into account a
material property of a material influencing the detection and/or of
a constraint.
[0090] According to further embodiments, the detector is movable.
According to further embodiments, the detector is freely movable.
In further embodiments, the detector is handheld. In typical
embodiments, the method includes again, repeatedly, or continuously
collecting detector data for image generation by means of the
evaluation system of the image generating apparatus, typically
during a detection period.
[0091] In some embodiments, the method further includes determining
at least one quality value from the collected detector data by
means of the evaluation system. In further embodiments, the method
includes again or repeatedly determining at least one quality value
form the collected detector data by means of the evaluation system.
Typically, determining, again determining, repeatedly determining,
or continuously determining takes place during a detection
period.
[0092] In particular, the detection model according to embodiments
of the invention can be generated algebraically, analytically,
numerically, statistically, or on the basis of measurement data, or
by combinations thereof.
[0093] In further embodiments, the detection model takes into
account at least one further material property and/or at least one
further constraint. Material properties can for example influence
the detection model because of the following effects: attenuation
of radiation, scattering of radiation, refraction of radiation,
diffraction of radiation, influence of electromagnetic fields,
influence of background radiation, signal noise, or influence of
errors in the measurement values of the detector as well as in
measurements of position and/or orientation of the detector.
Embodiments of the invention can include detection models that take
into account these and other effects.
[0094] Methods for image generation according to embodiments of the
invention can also take into account at least one constraint,
wherein the constraints can for example be the relative solid angle
between the detector and the source region of radiation, the
dimensions of the detector or the absence of material.
[0095] According to further embodiments, an image generating
apparatus for image generation is provided. The image generating
apparatus includes a detector for detection of radiation. The
detector can be a movable detector. The detector can be a freely
movable detector. The detector can be a handheld detector. The
radiation can be nuclear radiation. The image generating apparatus
further includes an evaluation system. The evaluation system
includes an interface system for transmitting detector data for
image generation to the evaluation system. Typically, detector data
include data with information about the detected radiation.
Typically, the detector data also include data with information
about the position and/or orientation of the detector for image
generation. The evaluation system further includes a data memory
portion for storing detector data. The evaluation system further
includes a program memory portion with a program for determining an
image generation rule for image generation on the basis of the
collected detector data, taking into account a detection model. In
typical embodiments, the detection model takes into account at
least one material property of at least one material influencing
the detection and/or at least one constraint.
[0096] In further embodiments, the interface system is an interface
system for transmitting detector data to the evaluation system.
Therein, the detector data typically include information about the
detected radiation. Typically, the data also include information
about the position and/or orientation of the detector. According to
further embodiments, the interface system is an interface system
for continuously transmitting detector data to the evaluation
system for image generation. The detector data can again include
information about the detected radiation and/or information about
the position and/or orientation of the detector. Typically, the
transmission is a transmission during the detection period.
[0097] According to further embodiments, the detection model takes
into account an attenuation of radiation, a scattering of
radiation, a refraction of radiation, a diffraction of radiation,
the influence of electromagnetic fields, the influence of
background noise, a signal noise, the influence of errors in the
measurement data of the detector and in the measurement of position
and/or orientation of the detector or further effects. In yet
further embodiments, the detection model takes into account
constraints such as the relative solid angle between the detector
and a source region of radiation, the dimension of the detector or
the absence of a material or combination of these constraints.
[0098] According to further embodiments image generation rules are
modified. In particular, with linear image generation rules, the
entries of the imaging matrix or system matrix are modified. In
typical embodiments, the system matrix is modified as soon as
further measurement data are available. Specifically, the
minimization of the norm of the difference between H applied to f
and a g_measured can be minimized again as soon as further
measurement data are available. Consequently, embodiments typically
include a continuous modification of the image generation rule.
Also, detection models can continuously be adapted and
enhanced.
Registration
[0099] According to further embodiments, detector data are
registered with compatible data. In some embodiments, a compatible
data are gained by an imaging rule from the given image. Such an
image can for example be an anatomical or body-functional image
that was taken beforehand (pre-operatively taken). In the case of a
linear imaging rule, this can be described by an imaging matrix H
as described above. The matrix H can depend on a location vector T,
in which information about the relative location and/or orientation
between the detector and the source of radiation is included.
Therein, T can describe a relative location in the sense of a rigid
registration or in the sense of a deformable registration. The
matrix H(T), i.e. dependent on T, is applied to a vector
f.sub.image as described above to obtain a vector with
(theoretical) detector data g=H(T)*f.sub.image associated with the
image.
[0100] The information contained in g represents predicted or
virtual or simulated detector data which are called simulation
detector data. As before, the vector g.sub.measured contains
information about detected radiation. The format (i.e. the
structure of the vector g) of the simulation detector data is
compatible with the measured detector data g.sub.measured. A
registration of detector data with such compatible data takes
place, according to some embodiments of the invention, in that the
distance |H(T)*f.sub.image-g.sub.measured| is minimized, i.e.
between g and g.sub.measured. The distance |.cndot.| can for
example be given by the L.sub.2 norm. The minimization takes place
overall location vectors T to obtain, as a results of the
minimization, an optimal location vector T. By using this optimal
location vector T, an image vector is associated to the measured
detector data by the matrix H(T), the image vector being compatible
with the image vector of the given image and being registered.
[0101] In typical embodiments the minimization is carry out by
algorithms such as the best-neighbour ansatz, a simplex-optimizer,
the Levenberg-Marquardt algorithm, the steepest gradient decent,
the conjugate gradient decent, or others.
[0102] The registration not only can take place by comparing the
detector data g as described above, but also by direct comparison
of the image data f gained from the detector data with a given
image. This comparison can be carried out by an image comparison
with the methods described above with respect to g, or else by a
comparison of single marking points designated for this purpose.
Also, other registration methods are possible.
[0103] The image comparison described above further allows
obtaining an estimation of the quality of the collected data (as
deviation between the image data gained from the detector data and
the given image).
[0104] Data can be indirectly registered with compatible data also.
Indirect registration is to be understood as a registration of a
first data set with a third data set by means of a second data set.
To this end, the first data set is registered with a second data
set, for example as described above. Then the second data set is
registered with a third data set. By using this registration the
first data set is finally registered with a third data set. For
example, the first data set can have been gained from a base image
such as an anatomical image taken pre-operatively. The second data
set can for example correspond to detector data of a first instance
in time, and a third data set to detector data of a later instance
in time. If the registration between the first data set, derived
from the base image, and the second data set has been successful,
the similarity between the second and third data set, consisting of
detector data, simplifies a registration if indirect registration
is used as described above.
[0105] In further embodiments, a method for image generation by
means of an image generating apparatus is provided. The method
includes detecting radiation by means of a detector of the image
generating apparatus. Detecting can take place during a detection
period. The radiation can be nuclear radiation. The detector can be
movable. The detector can be freely movable. The detector can be
handheld. The method further includes collecting detector data for
image generation by means of the evaluation system of the image
generating apparatus. Typically, the detector data include
information about the detected radiation. Typically, the detector
data also include information about the position and/or orientation
of the detector. The method further includes registering the
detector data with compatible data by means of the evaluation
system. In further embodiments, the compatible data are detector
data. According to further embodiments, the method for image
generation includes generating simulation detector data based on a
base image by means of the evaluation system. The compatible data
can be simulation detector data. In further embodiments, at least
one comparison function is used for registering the detector
data.
[0106] In further embodiments, the method includes an indirect
registration of simulation detector data with detector data by
means of second compatible data. In some embodiments, the second
compatible data are detector data. In other embodiments, the second
compatible data are second simulation detector data based on a
second base image.
[0107] Comparison functions can for example be cross correlation,
trans-information, block entropies, cross correlation rates, cosine
measure, extended Jaccard similarity, ratio image uniformity, sums
of squared distances or sums of absolute values of distances, or
further comparison functions.
[0108] In further embodiments, the base image is an anatomical or
body-functional image. In other embodiments, the second base image
is an anatomical or body-functional image. Anatomical images can
for example be a computer tomography, a magnetic resonance
tomography, an ultrasonic image, an optical image, or an x-ray
image. Body-functional images can for example be a positron
emission tomography, short PET, a single photon emission computer
tomography, short SPECT, or an optical tomography.
[0109] In further embodiments, an image generating apparatus for
image generation is provided. The image generating apparatus
includes a detector for detecting radiation. The detector can be
movable. The detector can be freely movable. The detector can be
handheld. The radiation can be nuclear radiation. The detector can
be a detector for detecting during a detection period. The image
generating apparatus further includes an evaluation system. The
evaluation system includes an interface system for transmitting
detector data for image generation to the evaluation system.
Typically, the detector data include information about the detected
radiation. Typically, the detector data also include information
about the position and/or orientation of the detector. The
interface system can be an interface system for continuously
transmitting detector data to the evaluation system. The evaluation
system further includes a program memory portion with a program for
registering detector data with compatible data.
[0110] In further embodiments, the compatible data are detector
data. According to further embodiments, the evaluation system
further includes a program memory portion with a program for
generating simulation detector data based on a base image. In
further embodiments, the compatible data are simulation detector
data. According to further embodiments, the program for registering
is programmed to register detector data with compatible data by
means of at least one comparison function.
[0111] According to further embodiments, the evaluation system
further includes a program memory portion with a program for
indirectly registering the simulation detector data with detector
data by means of second compatible data. The second compatible data
can be detector data. The second compatible data can be second
simulation detector data based on a second base image.
[0112] The comparison function can for example be comparison
functions as described above or other comparison functions.
Further, the base image or the second base image can have the same
or similar properties as the ones described above.
[0113] Embodiments of the invention also include registering
images. These images can for example be generated from detector
data or from other data sets. A registration of images can, for
example, take place by maximizing the similarity or minimizing the
dissimilarity of both images. For the minimization of the
dissimilarity or maximization of the similarity, comparison
functions can be used such as cross correlations,
trans-information, block entropies, cross correlation rates, cosine
measure, extended Jaccard similarity, ratio image uniformity, sums
of squared distances or sums of absolute values of distances. Other
information theoretic comparison functions may also be used. For
the minimization or maximization process itself, optimization
algorithms can be used with algorithms as the ones mentioned above
or others. Images can also be registered point-wise. To this end,
specifically chosen points in both images are set into relation.
The selection can take place automatically or interactively.
Algorithms for point-wise registration can for example be the
Umeyama or the Walker algorithm.
[0114] Finally, also an indirect image registration is possible. In
this case, the process includes registering a third image with a
second image, registering a first image with a third image, and
registering the first image with the second image using the
registration of the first image with the third image. The images
can be for example anatomical or body-functional images as in the
case of the registration of data sets. Such images can be gained
from detector data. The image can also be gained from other
detectors of the detection system such as for example by means of
computer tomography, magnetic resonance tomography, ultrasonic
sonography, picture taking of an optical camera or of an x-ray
device. Examples for organ-functional images are images gained from
the detector data but also positron emission tomography, short PET,
single photon emission computer tomography, short SPECT, or optical
tomography.
[0115] According to further embodiments, a method for image
generation includes generating a first image on the basis of a
collected detector data by means of the evaluation system. In
further embodiments, the method further includes a registration of
the first image with the second image. For registering the first
image with the second image, a minimization of the dissimilarity or
a maximization of the similarity can be used. In some embodiments,
a comparison function is used for the minimization or maximization.
Comparison functions can be the ones listed above or other
comparison functions.
[0116] According to further embodiments, a method for image
generation includes registering a third image with a second image,
registering the first image with a third image, registering the
first image with the second image by means of registering the first
image with a third image.
[0117] In some embodiments, the second image is an anatomical
image. In other embodiments, the second image is a body-functional
image. An anatomical image can be one of the anatomical images
described above or be a different anatomical image. A
body-functional image can be a body-functional image as described
above or be a different body-functional image.
Quality Control
[0118] To provide high quality, in particular up-to-date high
quality images, embodiments of the invention provide methods and
devices for quality control of the detector data as well as of the
generated images. In some embodiments quality control takes place
continuously. In this way, the quality and validity of a generated
image is checked. In further embodiments, the quality control takes
place already during the detection period.
[0119] FIG. 12 shows a typical process of quality control according
to embodiments of the invention. A time axis 620 is shown,
symbolizing the course of time (from left to right). In FIG. 12, a
detection period 622 is further shown. Further, with respect to the
same time axis, a quality determination period 624 is depicted.
Typically, the quality determination period 624 starts after the
start of the detection period when detector data are already
available. The quality determination period 624 can end before the
detection period, at the same time as the detection period or after
the detection period. Typically, the quality determination period
624 ends after the detection period. The distances between marks on
the line symbolizing the quality determination period 624 symbolize
themselves periods in which a quality determination process takes
place, such as for example determination of a quality value by the
evaluation unit. The distances 626 and 628 symbolize the first,
respectively the last, quality determination process. In further
embodiments of the invention, an alert signal 629 is output if data
gathered, respectively collected, by the evaluation unit do not
pass quality control. Such a warning signal can be output for
example acoustically, optically, haptically or by combinations
thereof. Such a warning signal can make a user, for example a
surgeon, be aware that the images determined from the detector data
may not be reliable at least at the instance of time of the output
of the warning signal.
[0120] Quality control is typically carried out on the basis of at
least one quality criterion. With respect to one or more quality
criteria, a quality value is calculated. Also, several quality
values can be calculated for one, respectively more, quality
criteria, for example if a quality value is determined that depends
on a respective imaging region. Therein, for example, the validity
or quality of an image can be rejected if such a quality value does
not fulfil one ore more quality criteria, i.e. does not satisfy
them. Conversely, an image can be regarded as valid if a quality
value satisfies a quality criterion or satisfies several quality
criteria. Here and in the following, an image can also be
understood as a specified imaging region associated to the
respective quality value.
[0121] Examples for a quality criteria are the following: the
similarity between a first and a second image, wherein one of the
images or both of the images may be generated from detector data;
the conditioning of an image generation rule for generating an
image; the relevance of data, such as detector data, for an image
element; the plausibility of the image generation from data, such
as detector data or data from a second image; the uniformity of
data, such as detector data; or the risk of false generation
because of faulty data, such as detector data.
[0122] The similarity between a first and a second image can be
determined similarly as in the case of registration. In particular,
already registered images can again be compared with each other for
similarity. The images can therein have been registered by direct
image registration or by data registration. The images can for
example be anatomical or organ-functional images as the ones
described above, or others.
[0123] If the image generation rule is, according to some
embodiments, a linear rule the conditioning of the image generation
rule can be given by the conditioning of the imaging matrix or the
system matrix. In particular, in a linear, discrete case, the
conditioning number of the imaging matrix H (see above) can be
calculated. A conditioning number can be calculated by analysis of
the spectrum of the singular values of the matrix or by similar
matrix decomposition measures (for example relation of largest to
smallest eigenvalue or number of eigenvalues being above or below a
threshold value). In this example, the quality criterion is a
threshold value for the conditioning number. If the calculated
conditioning number, i.e. a quality value, is smaller (respectively
larger, depending on the definition of the conditioning number)
then the threshold value, the data, such as detector data, do not
fulfil the quality criterion, and therefore an image generated
therefrom is rejected. If, on the other hand, the calculated
conditioning number is larger (respectively smaller) then the
threshold value, the quality of the data, such as detector data,
and an image reconstructed therefrom are accepted.
[0124] Similarly, the quantity named with the technical term
sparsity of a matrix row or of a matrix column can be a quality
value, and a threshold value with respect to this quantity can be
used as a quality criterion. A row or a column of a matrix is
sparse if less than a number of entries determined by the threshold
value are different from zero (respectively from numerical zero,
i.e., smaller than a given epsilon-threshold). If a matrix column
is too sparse an image element depends on two few measurements, and
therefore a high risk of false generation exists for this image
element. If a matrix row is too sparse the measurement value
associated with this row is responsible for two few image elements,
which again may lead to a high risk or false generation.
[0125] Correspondingly, also the relevance of data for an image
element can be used as a quality criterion. For a linear image
generation rule the relevance of a row or column can for example be
associated with a threshold value for the sum of all entries of the
row or column.
[0126] The plausibility of an image generation for example takes
into account a constraint. Examples for constraints are the maximal
amount of radiation, the gradient of the sum of maximal radiation,
minimal radiation, radiation associated to image elements that
obviously cannot contain radiation sources (for example regions
filled with air), and others. Depending on the degree of
plausibility, a corresponding quality value can be associated.
[0127] The uniformity of detector data is determined by the spatial
distribution of measurements. Uniform measurements are present if
the measurements are distributed uniformly around the region to be
reconstructed. A measure for uniformity is formed by the deviation
of the actual measurements from a completely uniform measurement. A
quality criterion is formed by a threshold value with respect to
this uniformity.
[0128] In typical embodiments of the invention, a quality control
based on the quality criteria named above, or on others, is carried
out successively, preferably quasi-continuously (as shown in FIG.
12). In further embodiments the results of quality control is
output to a user by the output system. In particular, as described
above, the output can be visual, acoustical or haptic. For example,
the output can take place by a coarsening of the image resolution
in the corresponding image region. Thereby, a user is prevented
from putting false confidence into possibly faulty images.
According to further embodiments of the present invention, a method
for image generation by means of an image generating apparatus is
provided. The method includes detecting radiation by means of a
detector. Detecting can take place during a detection period. The
radiation can be nuclear radiation. The detector can be movable.
The detector can be freely movable. The detector can be portable in
the hand. The method further includes collecting detector data for
image generation by means of an evaluation system of the image
generating apparatus. In typical embodiments the detector data
include information about the detected radiation. In further
typical embodiments, the detector data comprise information about
the position and/or orientation of the detector. The method further
includes determining at least one quality value from the collected
detector data by means of the evaluation system. In typical
embodiments the determination is a repeated determination or a
continuous determination, typically during the detection
period.
[0129] In further embodiments, the method includes again,
repeatedly, or continuously collecting detector data for image
generation by means of the evaluation system of the image
generating apparatus, preferably during the detection period.
[0130] In further embodiments, the at least one quality value is
determined with respect to at least one quality criterion. A
quality criterion can for example be the similarity between a first
image generated from the collected detector data and a second
image, the conditioning of an image generation rule for image
generation from the collected detector data, the relevance of the
collected detector data for an image element, the plausibility of
image generation from the collected detector data, the uniformity
of the collected detector data, or the risk of false generation
because of faulty detector data. Apart from these, further quality
criteria may be used.
[0131] Further embodiments, the method includes outputting the at
least one determined quality value to a user. Further, other
embodiments include outputting a warning to a user if the at least
one quality value does not fulfil at least one quality criterion.
Outputting the quality value or the warning can take place
visually, acoustically, haptically, or by combinations thereof.
[0132] In further embodiments, an image generating apparatus for
image generation is provided. The image generating apparatus
includes a detector for a detection of radiation. The detector can
be a detector for detecting radiation during a detection period.
The detector can be movable. The detector can be freely movable.
The detector can be variable in the hand. The detector can be
nuclear radiation. The image generating apparatus further includes
an evaluation system. The evaluation system includes an interface
system for transmitting detector data for image generation to the
evaluation system. Typically, detector data include information
about the detected nuclear radiation. Typically, the detector data
further include information about the position and/or orientation
of the detector. The evaluation system further includes a data
memory portion for storing the detector data. The evaluation system
further includes a program memory portion with a program for
determining at least one quality value with respect to image
generation from the detector data. The program can also be a
program for again, repeatedly, or continuously determining at least
one quality value with respect to image generation from the
detector data. Therein, determining at least one quality value can
take place during a detection period.
[0133] In further embodiments, the interface system is an interface
system for again, repeatedly, or continuously transmitting detector
data to the evaluation system. The transmission can take place
during the detection period. The detector data can include
information about the detected radiation. The detector data can
also include information about the position and/or orientation of
the detector.
[0134] In further embodiments, the program for determining at least
one quality value is a program for determining, again determining,
repeatedly determining, or continuously determining a quality value
with respect to at least one quality criterion.
[0135] In further embodiments, the image generating apparatus for
image generation further includes an output system, which includes
at least one output unit. In further embodiments, the output unit
is an output unit for outputting the at least one determined
quality value to a user. In further embodiments, the output unit or
a further output unit is an output unit for outputting a warning to
a user if the at least one quality value does not fulfil at least
one quality criterion. The one output unit or the other output unit
can be output units for instructions or warnings to the user in
visual, acoustical, or haptical form, or in combination forms
thereof. The outputs can be combined with an instruction to a user
for improving the quality value, as described further below.
Enhancement of Image Generation
[0136] According to embodiments of the invention, methods and
apparatuses for image generation are provided in which the quality
of image generation is enhanced. In typical embodiments, a quality
is continuously enhanced. In particular, the quality can already be
enhanced, or continuously enhanced, during the detection
period.
[0137] In typical embodiments, the image generation takes place on
the basis of a linear image generation rule. This image generation
can for example take place by applying an imaging matrix or system
matrix H to a vector f, wherein H and f have denotations explained
above. The image generation can, as described above, take place by
comparison of the result vector g=H*f with the detector data vector
g.sub.measured (respectively by equivalent methods). The image
generation, also called reconstruction, takes place by minimization
of the distance between the vector g and the vector g.sub.measured
as a function of f, as described above.
[0138] An improvement of image generation can take place by
different ways that include: improving the starting value of vector
f in the minimization problem, enhancing the image generation rule,
in particular the image matrix H.
[0139] As starting value for the minimization problem, a vector
f.sub.start can for example be used, the contained information of
which is derived from a given image, for example from a
pre-operative anatomical or organ-functional image. This helps to
avoid getting a wrong solution while solving the minimization
problem (such as being trapped in a local minimum that does not
correspond to the desired solution). Also, the computing time can
be decreased because one starts with a nearly correct solution
already. In this way, a good solution of the minimization problem,
i.e. a good image f, can be obtained with reduced effort.
[0140] An improvement of the imaging rule, respectively of the
imaging matrix H, can in particular take place by calculating at
least one quality value, wherein the quality value is the same as
in the quality control of data described above, or can be a further
quality value. Additionally, the imaging matrix H is modified while
taking into account a quality value. In particular, the imaging
matrix H is modified in such a way that the modified matrix H
better satisfies one or several quality criteria.
[0141] For example, rows or columns can be eliminated which have
been recognized as being too sparsely filled according to a
threshold with respect to the sparsity of a matrix. Likewise, rows
or columns of the imaging matrix H can be eliminated which do not
satisfy the criterion of relevance. Instead of pure elimination,
such rows or columns can be combined, whereby also the
corresponding image elements (entries of f), respectively detector
measurement values (entries of g), are correspondingly
combined.
[0142] The uniformity can further be improved, for example by
combining the detector data of neighbouring measurements such that
rather uniformly distributed effective measurements are obtained.
By such combinations, the imaging matrix becomes smaller, and also
for this reason the reconstruction is numerically better
solvable.
[0143] On the other hand, information may be lost by such
combination. To compensate the loss of information at least
partially, a higher weight can be attributed to the entries
averaged from several values, which takes into account their higher
statistical significance. For example, the contribution of such
entries to the distance norm |.cndot.| can receive a higher
weight.
[0144] According to further embodiments, the following further
methods are used for enhancing image generation:
Use of Surface Information
[0145] If the surface of the spatial region containing the
radiation source is known, possible mappings can be eliminated that
contain information about image elements which do not lie within
this surface. In particular, this surface can for example be the
surface of the body of a patient. This surface can be scanned by a
laser range scanner, a laser surface pattern scanner, a laser
pointer surface scanner, stereoscopic camera systems,
time-of-flight cameras and further surface capturing systems.
[0146] Such surface information can also be determined on the basis
of the geometry of an object tracked by the tracking system and its
tracked trajectory: if an object cannot penetrate into the patients
tissue, then the spatial areas traversed by this objet must be
filled with air and can hence not contain any radiation sources. In
particular, this object can be formed by the detector itself or be
integral with the detector.
Use of Anatomical Information
[0147] If, for example in the case of medical imaging, the anatomy
in a region of the generated image is known, constraints can be set
on the basis of the knowledge of the anatomy and can be taken into
account. A constraint can for example be that body part such as
bones or the air tube (which, for example with a certain tracer,
cannot form nuclear radiation sources) cannot show any radiation
activity. In this way, possible mappings can be eliminated that
would falsely ascribe a radiation activity to such regions.
Anatomical information can for example be obtained by anatomic
images captured before. These can be registered with current data.
Also, standard data can be used, for example from anatomic atlases,
which can also be registered with currently generated images.
Anatomical information can also be presently obtained by further
detectors of the detection system, such as for example ultrasonic
devices, computer tomographs, radiographs, optical cameras,
magnetic resonance tomography devices, and others.
Use of further Radiation Detectors
[0148] The detection system can include further radiation
detectors. Further detector data can also be used for image
generation. Further detectors can be radiation detectors, in
particular radiation detectors for nuclear radiation. The further
detectors can be movable radiation detectors. The further radiation
detectors can also be fixed radiation detectors. For instance, the
table on which the radiation distribution lies may include a gamma
camera. In further embodiments, floor, sealing, and/or wall-mounted
detectors are used.
[0149] According to further embodiments, a method for image
generation by means of an image generating apparatus is provided.
The method includes detecting radiation by means of the detector of
the image generating apparatus. Detecting can take place during a
detection period. The radiation can be nuclear radiation. The
detector can be movable. The detector can be freely movable. The
detector can be handheld. The method further includes collecting
detector data for image generation by means of an evaluation system
of the image generating apparatus. Typically, the detector data
include information about the detected radiation. Typically,
detector data also include information about the position and/or
orientation of the detector. The method further includes
determining an image generation rule by means of the evaluation
system on the basis of the collected detector data. The method
further includes modifying the image generation rule on the basis
of at least one quality value. In typical embodiments, the
modification is a repeated or continuous modification of the image
generation rule. Typically, modifying takes place during the
detection period.
[0150] In further embodiments, the collection of detector data is
an anew, repeated, or continuous collection of detector data. In
further embodiments, the determination of an image generation rule
is an anew, repeated, or continuous determination of an image
generation rule. Typically, determining, again determining,
repeatedly determining, or continuously determining takes place
during a detection period.
[0151] In further embodiments, the at least one quality value is
determined with respect to at least one quality criterion. Quality
criteria can be the same as the ones described in the section about
the quality control, or can be further quality criteria. Further
quality criteria can be criteria on the basis of constraints. Such
constraints can consist of using surface information, anatomical
information or other information. Also, use of further radiation
detectors can be made, and thus further detector data for
modifying, again modifying, repeatedly modifying or continuously
modifying the image generation rule can be used.
[0152] In further embodiments, an image generating apparatus for
image generation is provided. The image generating apparatus
includes a detector for detecting radiation. The detector can be a
detector for detecting during a detection period. The detector can
be movable. The detector can be freely movable. The detector can be
handheld. The radiation can be nuclear radiation. The image
generating apparatus further includes an evaluation system. The
evaluation system includes an interface system for transmitting
detector data to the evaluation system for image generation.
Detector data typically also include information about the position
and/or orientation of the detector. The evaluation system further
includes a data memory portion for storing detector data. The
evaluation system further includes a program memory portion with a
program for determining an image generation rule on the basis of
the collected detector data. The evaluation system further includes
a program memory portion with a program for modifying the image
generation rule on the basis of at least one quality value. The
modification is typically an anew, repeated, or continuous
modification of the image generation rule. The program for
modifying, again modifying, repeatedly modifying or continuously
modifying the image generation rule is, according to typical
embodiments, a program for modifying, again modifying, repeatedly
modifying, or continuously modifying the image generation rule on
the basis of at least one quality value during the detection
period.
[0153] In further embodiments, the interface system is an interface
system for again, repeatedly, or continuously transmitting detector
data to the evaluation system. Typically the transmission is a
transmission during a detection period.
[0154] In typical embodiments, the program for determining at least
one quality value is a program for determining at least one quality
value with respect to at least one quality criterion. Quality
criteria can be the ones described above in the section "quality
control", or can be other quality criteria.
[0155] In further embodiments, the image generating apparatus
further includes an output system with at least one output unit. In
further embodiments, the output unit is an output unit for
outputting the at least one determined quality value to a user. In
other embodiments, the output unit is an output unit for outputting
a warning to a user if the at least one quality value does not
satisfy at least one quality criterion. Outputting a quality value
or a warning to a user can take place in visual, acoustical, or
haptic form, or in a combination form thereof.
Outputting an Instruction to a User
[0156] Embodiments of the present invention include outputting an
instruction to a user. A user can be a human user. A user can also
be another living being. Alternatively, a user can also be an
inanimate object, for example a machine. In particular, typical
embodiments include outputting of an instruction to a user for
further moving the detector in dependence on the detector data
already collected. Typical embodiments include a continuous
instruction for detection on the basis of a continuous quality
control, which has been described above. The output takes place by
means of the output system, in particular in optical, acoustical or
haptic form, or by combinations thereof. Specifically, instructions
for further movement of the detector are given in such a way that,
when followed, a quality of the collected detector data is
improved. Typically, instruction for further moving the detector in
dependence of the collected data is output such that, if followed,
the quality of the detector data is presumably enhanced the most.
Instructions can for example take place in form of outputting an
arrow pointing in the direction in which further measurements shall
be made.
[0157] Typically, the calculation of the current quality or rating
or validity of the collected detector data precedes the outputting
of an instruction, and also a calculation how the quality of the
data would change if further detector data were available, in
particular detector data with information about the detected
radiation measured from different orientations or positions of the
detector.
[0158] FIG. 13 shows iterative method steps according to
embodiments of the invention. One of the iterative steps is a
movement of the detector. In typical embodiments, a freely movable,
for example carryable detector is used. After or during movement,
detection 614 of radiation by the detector takes place. Afterwards,
or simultaneously, a collection 615 of detector data with
information about the detected radiation is carried out by the
evaluation system. Typically, further detector data such as
position and/or orientation of the detector collected, normally
synchronized with the detector data with information about the
detected radiation. On the basis of the detector data, a
determination 616 of a quality criterion takes place by the
evaluation unit. Then, an output 618 of an instruction to a user
takes place. According to embodiments of the invention, the output
618 instructs a user to move the detector in a way that a movement
corresponding to the instruction leads to the subsequent
measurement of suitable detector data. Suitable detector data are
typically detector data that enhance image generation.
[0159] Typically, such a position and/or orientation of the
detector is output to the user that would presumably enhance the
quality the most. An output, for example in acoustical form, can be
represented in form of an intensifying signal sound. An output in
haptic form can, for example, be the provision of a sensation of
resistance or of being pulled. This sensation can for example be
effected by mechanical guidance or by electrical stimulation of
muscles or of the brain.
[0160] To compute the orientations and positions which presumably
enhance imaging, anatomical or organ-functional images can also be
used.
[0161] According to further embodiments, a method for image
generation by means of an image generating apparatus is provided.
The method includes detecting radiation by means of a detector of
the image generating apparatus. Detection can take place during a
detection period. The radiation can be nuclear radiation. The
detector can be movable. The detector can be freely movable. The
detector can be handheld. The method further includes collecting
detector data for image generation by means of an evaluation system
of the image generating apparatus. Typically, detector data include
information about the detected radiation. Typically, the detector
data also include information about the position and/or orientation
of the detector. The method further includes outputting an
instruction to a user for further moving the detector in dependence
of the collected detector data. According to typical embodiments,
the instruction relates to at least a part of the remaining
detection period.
[0162] According to further embodiments, the collection is an anew,
repeated, or continuous collection of detector data. In further
embodiments, outputting an instruction is again, repeatedly, or
continuously outputting an instruction to a user for further moving
the radiation detector. In typical embodiments, the outputting,
anew outputting, repeated outputting or continuous outputting of an
instruction to a user for further moving the radiation detector
includes outputting the position and/or orientation of the detector
that, if adopted by the detector, would enhance image generation
according to at least one quality value in a accordance with a
prediction. Typically, the positions and/or orientations are
output, which, if assumed by the detector, would most enhance image
generation according to a quality value in light of a prediction.
Outputting can take place visually, acoustically, haptically, or by
combinations thereof.
[0163] In further embodiments, an image generating apparatus for
image generation is provided. The image generating apparatus
includes a detector for detecting radiation. The detector can be a
detector for detecting radiation during a detection period. The
detector can be movable, freely movable, or handheld. The radiation
can be nuclear radiation. The image generating apparatus further
includes an evaluation system. The evaluation system includes an
interface system for transmitting detector data for image
generation to the evaluation system. Detector data typically
include information about the detected radiation. Detector data
typically also include information about the position and/or
orientation of the detector. The evaluation system further includes
a data memory portion for storing the detector data. The image
generating apparatus further includes an output system for
outputting an instruction to a user how to further move the
detector in dependence of the detector data. In typical
embodiments, the instruction relates to at least a part of the
remaining detection period.
[0164] In further embodiments, the interface system is an interface
system for again, repeatedly, or continuously transmitting detector
data to the evaluation system. In further embodiments, the output
system for outputting an instruction to a user is an output system
for outputting an anew, repeated, or continuous instruction to a
user for further moving the detector in dependence of the detector
data. Typically, the instructions relate to at least a part of the
remaining detection period. In typical embodiments, the output unit
is an output unit for outputting the position and/or orientation of
the detector which, if assumed by the detector, would enhance, and
preferably most enhance, image generation according to at least one
quality value in accordance with a prediction. The output unit can
be an output unit for an output in visual, acoustical, or haptic
form or in a combination form thereof.
Freehand Acquisition
[0165] Intrinsic problems of processing detector data, which occur
in particular with a freely movable detector or a freehand
detector, arise because measurements can take place in principle at
each instant in time and with arbitrary position and/or orientation
of the detector. Thereby, data may be gathered while the detector
is not pointed towards the radiation source that is to be detected.
Similarly, further sources for unsuitable data exist. Such data can
deteriorate image generation. Such unsuitable data can deteriorate
an imaging matrix, for example with respect to relevance or
sparsity.
[0166] FIG. 14 shows a freely movable detector 110 being moved
along an arbitrary trajectory. The movement direction is indicated
by arrows along the trajectory. Positions and orientations that
follow in time to a first position and orientation are depicted
with dashed lines. The detector 110 measures the emissions of a
radiation source 10 within a spatial region 30 at different,
generally arbitrary instances in time. The radiation source 10 can
for example be a nuclear radiation distribution in the body of a
living being. FIG. 14 shows at least one position and orientation
630 of the detector which presumably leads to unsuitable detector
data with respect to the measured radiation. Unsuitable detector
data typically deteriorate image generation.
[0167] For this and other reasons, data acquisition with freely
movable detectors needs quality control even more than detection
with fixed or limitedly movable detectors. Besides quality control,
an improvement of the image generation rule can take place.
[0168] According to embodiments of the invention, a quality control
and/or an active enhancement of the image generation rule takes
place during the detection period, in contrast to a post selection.
In typical embodiments, quality control takes place repeatedly or
successively, typically quasi-continuously or continuously.
[0169] Likewise, the enhancement of an imaging rule can take place
repeatedly or successively, typically quasi-continuously or
continuously. An enhancement can take place as for example
described in the section "enhancing image generation" or in another
way.
[0170] According to further embodiments, a method for image
generation by means of an image generating apparatus is provided.
The method includes detecting radiation by means of a movable
detector of the image generating apparatus. Typically, detecting
takes place during a detection period. The detector can be freely
movable. The detector can be handheld. The radiation can be nuclear
radiation. The method further includes changing the position and/or
orientation of the detector. In typical embodiments, changing the
position and/or orientation of the detector takes place during the
detection period. Changing can be freely changing the position
and/or orientation of the detector. Changing can also be again,
repeatedly, or continuously changing. The method further includes
collecting detector data for image generation by means of the
evaluation system of the image generating apparatus. Typically,
collecting is again, repeatedly, or continuously collecting
detector data. Typically, collecting takes place during the
detection period. The detector data usually include information
about the detected radiation. The detector data usually also
include information about the position and/or orientation of the
detector. The method further includes determining at least one
quality value from the collected detector data by means of the
evaluation system.
[0171] In further embodiments, determining at least one quality
value takes place again, repeatedly, or continuously, typically
during the detection period. In further embodiments, the at least
one quality value is determined with respect to at least one
quality criterion. Quality criteria can for example be the quality
criteria described in the section "quality control", or can be
other quality criteria.
[0172] According to further embodiments, an image generating
apparatus for image generation is provided. The image generating
apparatus includes a movable detector for detecting radiation. The
movable detector is, according to typical embodiments, a detector
for detecting radiation during a detection period. The detector can
be freely movable. The detector can be handheld. The radiation can
be nuclear radiation. The image generating apparatus further
includes an evaluation system. The evaluation system includes an
interface system for continuously transmitting detector data for
image generation to the evaluation system. Typically, detector data
include information about the detected radiation. Typically,
detector data include also information about the position and/or
orientation of the detector. According to further embodiments, the
interface system is an interface system for continuously
transmitting the detector data during the detection period. The
evaluation system further includes a data memory for storing the
detector data. The evaluation system further includes a program
memory portion with a program for determining at least one quality
value with respect to image generation from the detector data.
According to further embodiments, the program for determining at
least one quality value is a program for again, repeatedly, or
continuously determining at least one quality value with respect to
image generation from the detector data. In typical embodiments,
the program for determining at least one quality value is a program
for determining, again determining, repeatedly determining, or
continuously determining at least one quality value with respect to
image generation from the detector data during the detection
period.
[0173] In further embodiments, the program for determining at least
one quality value is a program for determining at least one quality
value with respect to at least one quality criterion. The at least
one quality criterion can be a quality criterion as described in
the section "quality control", or can be a further quality
criterion.
[0174] According to further embodiments of the invention, which can
be combined with any of the embodiments, the method for image
generation includes generating an image by minimization of the
dissimilarity or maximization of the similarity, wherein preferably
at least one reconstruction method for minimization or maximization
is used. The at least one reconstruction method can be an algebraic
reconstruction method, short ART, a maximum likelihood expectation
value maximization algorithm, short MLEM, an iterative matrix
inversion method such as the Jacobi method, the Gauss-Seidel
method, or the over-relaxation method, a direct matrix inversion
method such as the singular value decomposition or a regularised
matrix inversion method such as the singular value decomposition
with Tikhonov regularization.
[0175] According to further embodiments of the invention, which can
be combined with other embodiments, the method for image generation
is a method for image generation for medical purposes. According to
further embodiments, the method for image generation includes
collecting body data of a living being by means of the evaluation
system. Typically, body data include respiration frequency and/or
heartbeat frequency. Typically, the body data also include data
with respect to form, position and/or orientation of the body. In
further typical embodiments, the body data with respect to
respiration frequency and/or heartbeat frequency are synchronized
with the body data with respect to form, position and/or
orientation of the body, and are collected in synchronized way. The
gathering of body data of the living being can for example be
effected by the tracking system.
[0176] According to further embodiments, the method for image
generation further includes modifying the image generation rule on
the basis of the collected body data. Thereby, movements of the
body, for example by respiration or heartbeat, can be taken into
account for image generation. This leads to an enhanced image
generation. Also, registration of images or the registration of
detector data is facilitated thereby.
[0177] According to further embodiments, that can be combined with
other embodiments, the method for image generation includes
gathering of data of at least one instrument, preferably a medical
instrument, by means of the evaluation system. According to further
embodiments, the method further includes a registration of data of
medical instruments with respect to data and/or simulation detector
data by means of the evaluation system. In typical embodiments, the
method further includes generation of a combination image on the
basis of the registration.
[0178] According to further embodiments, the method further
includes a tracking of data of medical instruments by the tracking
system.
[0179] According to further embodiments, the method includes
generating an instrument image on the basis of the collected
instrument data by means of the evaluation system. According to
further embodiments, the method further includes a registration of
the instrument image with the first image and/or the second image
and/or the third image and/or with an already registered image.
Further, the method typically includes generating a combination
image on the basis of the registration.
[0180] According to further embodiments, the method includes
outputting a combination image by means of the output system.
According to further embodiments, the method includes instructing a
user, on the basis of the combination image, how to use the medical
instruments. According to yet further embodiments, the method
includes guiding a user while using the medical instruments by
means of a guiding system on the basis of the instrument data. The
guiding system can include a guiding unit guiding a user in haptic,
acoustic or visual way, or by combinations thereof.
[0181] In particular, instructing the user, on the basis of a
combination image, on how to use the medical instruments, or
guiding the user while using the medical instruments by a guiding
system can take place for example by visualization of a virtual
reality, visualization of an augmented reality, by layer and
multi-layer visualization, frequency-modulated sound,
amplitude-modulated sound, pulse-modulated sound, by combinations
thereof, or in any other way.
[0182] According to further embodiments, the method for image
generation includes positioning the living being. Positioning can
take place for example by a positioning system which includes a
positioning unit. Such a positioning unit can position the living
being in any desired position and/or orientation according to some
embodiments.
[0183] According to further embodiments of the invention, the image
generating apparatus for image generation is an image generating
apparatus for image generation for medical purposes. According to
further embodiments, the image generating apparatus includes at
least one sensor for detecting body data of a living being.
Typically, the body data include respiration frequency and/or
heartbeat frequency of the living being. According to further
embodiments, the image generating apparatus includes a tracking
unit for gathering body data of the living being. Typically, the
body data include the form, position and/or orientation of the
body. According to further embodiments, the evaluation system
further includes a program memory portion with a program for
synchronized collection of body data of the living being.
Typically, the evaluation system further includes a data memory
portion for storing the synchronized body data of the living being.
According to further embodiments, the evaluation system further
includes a program portion with a program for modifying the image
generation rule on the basis of the collected body data.
[0184] According to further embodiments, the evaluation system of
the image generating apparatus further includes an interface for
collecting data of at least one instrument, typically of at least
one medical instrument. Further, the evaluation system includes,
according to embodiments of the invention, a program memory portion
with a program for generating an instrument image on the basis of
the instrument data.
[0185] According to further embodiments, the evaluation system
includes a program memory portion with a program for registering
data of medical instruments with detector data and/or simulation
detector data. Further, the evaluation system includes a program
memory portion with program for generating a combination image on
the basis of the output of the program for registering the data of
medical instruments according to some embodiments.
[0186] According to further embodiments, the evaluation system
includes a program memory portion with a program for registering
the instrument image with the first image and/or the second image
and/or the third image and/or with an already registered image.
Further, the evaluation system typically includes a program memory
portion with a program for generating a combination image on the
basis of the output of the program for registering the instrument
image.
[0187] According to further embodiments, the output system of the
image generating apparatus includes an output unit for output of
the combination image. According to further embodiments, the output
system includes an output unit for instructing a user how to use
the medical instruments on the basis of the combination image.
According to further embodiments, the image generating apparatus
includes a guiding system for guiding the user while using the
medical instruments on the basis of the instrument data. The
guiding system includes at least one guiding unit.
[0188] The output unit for instructing a user how to use the
medical instruments on the basis of the combination image as well
as the guiding system for guiding the user while using the medical
instruments can communicate signals to the user in haptic,
acoustic, or visual form, or in a combination form thereof. The
output unit can also be identical with the guiding unit of the
guiding system. The output unit can also be different from the
guiding unit of the guiding system. The output unit and/or the
guiding unit can be units for visualization of a virtual reality,
for visualization of an augmented reality, for layer and multilayer
visualization, for frequency-modulated sound output, for
amplitude-modulated sound output, for pulse-modulated sound output,
or for output of combinations thereof, or can be units for output
in a different way.
[0189] According to further embodiments of the invention, the image
generating apparatus further includes a positioning system for
positioning the living being. The positioning system includes at
least one positioning unit. In typical embodiments, the positioning
unit can position the living being in any desired position and/or
orientation in space.
[0190] In the following some additional embodiments will be
described (embodiments 1 to 30):
[0191] 1. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery based on pre-operative
data and tracked radiation detectors, wherein the device includes:
(a) a radiation detector; (b) a tracking system for synchronously
tracking the position and orientation of said radiation detector
and for readout; (c) a pre-operative nuclear image; (d) a data
processing system which communicates with the radiation detector
and with the tracking system and is adapted to read the
pre-operative nuclear image for allowing a three dimensional
reconstruction of the nuclear image and/or the computation of a
corresponding quality value from a list of readout data, positions
and orientations of the radiation device and the pre-operative
nuclear image; and (e) a display for displaying the reconstructed
image.
[0192] 2. A device for intra-operative three dimensional nuclear
imaging, 3D-visualization and image-guided surgery based on
pre-operative data and tracked radiation detectors, the device
including: (a) a radiation detector; (b) a tracking system for
tracking the position and orientation of the radiation detector and
of its readout data in synchronized form; (c) a pre-operative
nuclear image; (d) a data processing system which communicates with
the radiation detector and with the tracking system and is able to
read the pre-operative nuclear image for allowing the spatial
registration of the list of readout data, positions and
orientations of the radiation device; and (e) display for
displaying the registered images.
[0193] 3. A device for intra-operative three dimensional nuclear
imaging, three dimensional visualization and image-guided surgery,
based on pre-operative data and tracked radiation detectors as
described in the embodiment 2 and also including a system for
correct patient positioning based on the output of the
registration.
[0194] 4. A device for intra-operative three dimensional nuclear
imaging, three dimensional visualization and image-guided surgery,
based on pre-operative data and tracked radiation detectors as
described in the embodiments 1 and 2, and further including: (a) a
three dimensional imaging device; (b) a second tracking system
which is the same as the first tracking system or which
communicates with the first tracking system and is co-registered
with it and determines the position and orientation of the three
dimensional imaging device; and (c) a second data processing unit,
which is the same as the first data processing system or which
communicates with the first data processing system, and which
communicates with the three dimensional imaging device and with the
second tracking system, thereby enabling to determine the position
and orientation of the body part that is imaged, and thus to
calculate the relative position and orientation of the body part
that is imaged and the radiation detector and to allow a movement
and deformation compensation; and or to allow attenuation and/or
scattering correction based on the three dimensional images.
[0195] 5. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided operation, based on pre-operative
data and tracked radiation detectors as described in embodiment 4,
wherein the three dimensional imaging device is of such form that
it generates for example ultrasonic images, x-ray based images,
magnetic resonance tomography images, optical images,
contrast-enhanced ultrasonic images, contrast-enhanced x-ray-based
images, functional magnetic resonance tomography images, dye-based
optical images, fluorescence images, reflection images,
auto-fluorescence images, etc.
[0196] 6. A device for intra-operative three dimensional nuclear
imaging, three dimensional visualization and image-guided surgery,
based on pre-operative data and tracked radiation detectors as
described in the embodiments 1 or 2, further including: (a)
artificial markings which are positioned on or in the body part to
be images; and (b) a second tracking system, which is the same as
the first tracking system or which communicates with the first
tracking system, and which determines the position and orientation
of the artificial markings and communicates with the data
processing unit, such that it allows to calculate the position and
orientation of the body part that is imaged and of the radiation
detector and allows movement and/or deformation compensation.
[0197] 7. A device for intra-operative three dimensional nuclear
imaging, three dimensional visualization and image-guided surgery,
based on pre-operative data and tracked radiation detectors as
described in the embodiments 1 or 2, and also including a
calibrated sensor for monitoring the position and orientation of
the body part that is imaged, wherein the sensor communicates with
the data evaluation unit, such that it allows to calculate the
relative position and orientation of the body part this is imaged
and of the radiation detector and allows movement and/or
deformation compensation.
[0198] 8. A device for intra-operative 3D-nuclear imaging, three
dimensional visualization and image-guided surgery, based on
pre-operative data and tracked radiation detectors as described in
the embodiments 1 or 2, and also including a sensor for monitoring
the respiration and a heart signal of the patient, wherein the
sensor communicates with the data processing unit, such that a
phase label is attached to each readout, position and orientation
of the radiation detector, such that movement and/or deformation
compensation for respiration, heartbeat, or both is possible.
[0199] 9. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or following embodiments, further including: (a) at least
one surgical instrument and (b) a third tracking system for
tracking the surgical instrument, wherein the third tracking system
is the same as the first tracking system or communicates with a
first tracking system, such that the relative position and
orientation of the surgical instrument and of the reconstructed
three dimensional image or registered pre-operative image can be
calculated and can be used for (a) guiding instruments to regions
of increased accumulation; (b) guiding instruments away from
regions of increased accumulation; (c) guiding instruments to
regions of low accumulation; (d) guiding instruments away from
regions of low accumulation; (e) simulating, at the tip of each
instrument, the radiation readout that each instrument would give
if it were a gamma probe; (f) displaying surgical instruments on
the display; and/or (g) detecting when the validity of the images
is lost because of the operation in the reconstructed or registered
volume by means of the instruments, and warning a surgeon.
[0200] 10. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or following embodiments, further including: (a) a
display of virtual reality and/or (b) a display of augmented
reality, such that the reconstructed 3D-gamma-emitting images and
the registered pre-operative images can be displayed three
dimensionally in visual, acoustic, haptic or in a combined way,
and/or in particular spatially registered with the image geometry
of some camera, wherein the camera includes laparoscope cameras and
cameras based on surgical microscopes, optical and
image-transparent head-mounted displays, optical and
image-transparent, stereoscopic surgical microscopes, optical and
image-transparent displays.
[0201] 11. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or any of the following embodiments, wherein the
radiation detector is one of the following: gamma probe; beta
probe; gamma camera; beta camera; mini gamma camera; or a
combination thereof.
[0202] 12. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or any of the following embodiments, wherein the tracking
systems are external tracking systems, for example including
optical tracking systems, magnetic tracking systems, mechanical or
robot arm-based systems, radio wave-based tracking systems, sound
wave-based tracking systems, etc., or internal tracking systems,
which for example include acceleration detector-based tracking
systems, potentiometer-based tracking systems, etc., or a
combination of external tracking systems and/or internal tracking
systems.
[0203] 13. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided operation, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or any of the following embodiments, wherein the displays
are the following: (a) visual displays, for example monitor
systems, which for example include: monitors, optically transparent
monitors, stereo monitors, stereo-optically transparent head
mounted displays, etc.; (b) acoustical displays, which for example
include frequency-coded feedback systems, pulse-coded feedback
systems, etc.; (c) haptic displays, which for example include force
feedback joysticks, force-torque feedback joysticks, etc., or (d)
some combination of visual, acoustical and/or haptic displays.
[0204] 14. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or following embodiments, further including: (a) a memory
system for the involved information, which communicates with a
first and second data processing unit and/or (b) a third data
processing unit, which communicates with a first and second data
processing unit, such that the full information or a part thereof
is stored as documentation material and/or an automatic report of
the procedure is generated.
[0205] 15. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided operation, based on pre-operative
data and tracked radiation detectors substantially as described
herein and with reference to and/or as illustrated in the appended
drawings.
[0206] 16. A device for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided operation, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or following embodiments, and further including a sensor
and/or a further data processing unit, which can be the same as the
first data processing unit or can communicate with a first data
processing unit for the online calculation or the tracking of
errors in the position and orientation of any of the tracked
objects and/or errors in the readout of the radiation record.
[0207] 17. A method for intra-operative, 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors, including: (a) detection of
radiation by means of a radiation detector; (b) synchronized
tracking of the position and orientation of the radiation detector
and its readings; (c) readout of at least one pre-operative nuclear
image; (d) 3D-reconstruction of a nuclear image from a list of
readings, positions and orientations of the radiation device and of
the pre-operative nuclear image and/or the computation of a
corresponding quality value; and (e) displaying the reconstructed
image.
[0208] 18. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided operation, based on pre-operative
data and tracked radiation detectors, including: (a) detection of
radiation by means of a radiation detector; (b) synchronized
tracking of position and orientation of the radiation detector and
its readings; (c) readout of at least one pre-operative nuclear
image; (d) spatially registering a list of readings, positions and
orientations of the radiation device; and (e) displaying the
registered image.
[0209] 19. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided operation, based on pre-operative
data and tracked radiation detectors as described in the embodiment
16, wherein the registration is successful by back projection of
the readout data, positions and orientations of the radiation
detector on a 3D-radioactive distribution.
[0210] 20. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided operation, based on pre-operative
data and tracked radiation detectors as described in embodiment 16,
wherein the registration is successful by forward projection of the
pre-operative nuclear image on the positions and orientations of
the radiation detector.
[0211] 21. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided operation, based on pre-operative
data and tracked radiation detectors as described in embodiment 16,
further including: (a) correctly positioning a patient based on the
output of the registration; and/or (b) adaptation of surgery plans,
wherein the output is used.
[0212] 22. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in the
embodiments 15 or 16, further including: (a) generation of
3D-images by using 3D-imaging devices; (b) synchronized tracking of
position and orientation of the 3D-imaging devices; (c)
determination of position and orientation and/or of the deformation
of the body part that is imaged from the 3D-images; (d) the
calculation of relative positions and orientations and deformations
of the body part that is imaged and of the radiation detector; (e)
the compensation of movement and/or deformation of the body part
that is imaged on the basis of this relative position and
orientation and/or compensation of the attenuation and/or
scattering based on 3D-images.
[0213] 23. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in the
embodiments 15 or 16, further including: (a) monitoring the
position and orientation and/or deformation of the body part that
is imaged by use of a calibrated sensor; (b) computation of the
relative positions and/or orientations and/or deformation of the
body part that is imaged and of the radiation detector; and (c)
compensation of movement and/or deformation of the body part that
is imaged based on this relative position and orientation.
[0214] 24. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in the
embodiments 15 or 16, further including: (a) using artificial
markings positioned on or in the body part that is imaged; (b)
tracking the position and orientation of the artificial markings;
(c) determining the position and orientation of the body part that
is imaged based on the position and orientation of the artificial
markings; (d) calculating the relative positions and orientations
of the body part that is imaged and of the radiation detector; and
(e) compensation of the movement and/or deformation of the body
part that is imaged based on this relative position and
orientation.
[0215] 25. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in the
embodiments 15 or 16, further including: (a) monitoring the
respiration and the heart signal of the patient by means of a
sensor; (b) determination of a phase for each reading, position and
orientation of the radiation detector; (c) compensation of the
movement and/or deformation because of respiration, heartbeat, or
both based on these phases.
[0216] 26. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or following embodiments, further including: (a) using at
least one surgical instrument; (b) determining the relative
positions and orientations of the surgical instruments and of the
reconstructed 3D-image or registered pre-operative image; (c) using
this relative position and orientation for (1) guiding instruments
to regions of enhanced accumulation, (2) for guiding instruments
away from regions of enhanced accumulation, (3) for guiding
instruments to regions of low accumulation, (4) for guiding
instruments away from regions of low accumulation, (5) for
simulating, at the tip of each instrument, the radiation reading
which would be given if each instrument were a gamma probe, (6)
displaying surgical instruments on the display, and/or (7) for
detecting and for warning a surgeon when the validity of the images
is lost by the operation in the reconstructed and registered volume
by means of the instruments.
[0217] 27. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or following embodiments, further including: (a)
displaying reconstructed images or registered pre-operative images
either visually, acoustically, or haptically, or in a combined way
in 3D, and/or in particular spatially registered with the imaging
geometry of each camera.
[0218] 28. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or following embodiments, further including: (a) a memory
system for the full information or a part thereof for documentation
purposes; and/or (b) generating an automatic report of the
procedure.
[0219] 29. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors as described in any of the
preceding or following embodiments, further including: (a) online
computation or tracking of errors in the position and orientation
of any of the tracked objects and/or of the error in the reading of
the radiation display; and (b) displaying the error for a signing a
level of confidence to the readings and/or compensating the error
for using the gathered information according to the level of
confidence, and consequently to be able to correct the error.
[0220] 30. A method for intra-operative 3D-nuclear imaging,
3D-visualization and image-guided surgery, based on pre-operative
data and tracked radiation detectors substantially as described
herein and with reference to/or as illustrated in the appended
drawings.
[0221] In the following yet further additional embodiments are
described (further embodiments 31 to 51):
[0222] 31. A device for reliable intra-operative 3D-tomographic
nuclear imaging, 3D-visualization of radioactive spatial
distributions and image-guided surgery by use of radiation
detectors, wherein the device includes: (a) a radiation detector;
(b) a tracking system for tracking the position and orientation of
the radiation detector in a synchronized way; (c) a first data
processing unit which communicates with the radiation detector and
the tracking system and which is able to evaluate the quality of
the gathered data and to determine the necessary projections for
reliable 3D-reconstructions; (d) a second data processing unit
which communicates with the radiation detector and the tracking
system and which is able to carry out a 3D-reconstruction based on
the readings of the radiation detector and the corresponding
positions and orientations; (e) a display that communicates with
the data processing unit and is able to display the necessary
projections for a reliable reconstruction to a surgeon and/or for
guiding him; (f) a second display that communicates with the data
processing unit and is able to display the valid reconstructed
3D-gamma emitting images to a surgeon and to thereby allow to guide
him/her to improve the measurement.
[0223] 32. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors, according to
embodiment 31, wherein the first and second data processing units
are the same or communicate with each other.
[0224] 33. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors, according to
embodiment 31, wherein the first and second display are the same or
communicate with each other.
[0225] 34. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to
embodiment 31, wherein the radiation detector is one of the
following: gamma probe, beta probe, gamma camera, beta camera, mini
gamma camera, or a combination thereof.
[0226] 35. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to
embodiment 31, wherein the tracking system is an external tracking
system, which for example includes an optical tracking system,
magnetic tracking system, mechanical or robot arm-based tracking
system, a radio wave-based tracking system, a sound wave-based
tracking system, etc. or an internal tracking system, which for
example includes an acceleration detector-based tracking system, a
potentiometer-based tracking system, etc., or any combination of an
external tracking system and/or internal tracking system.
[0227] 36. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to
embodiment 31, wherein the display is one of the following: (a) a
visual display, for example a monitor system, for example
including: monitors and optically transparent monitors, stereo
monitors, stereo-optical transparent head-mounted displays, etc.;
(b) an acoustical display, for example including frequency-coded
feedback systems, pulse-coded feedback systems, etc.; (c) a haptic
display, for example including force feedback joysticks,
force-torque feedback joysticks etc., or (d) a combination of
visual, acoustical and/or haptic displays.
[0228] 37. A method for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors, including: (a)
synchronized collection of readout data of the radiation detector
and of the position and orientation of the radiation detector; (b)
evaluation of the quality of the collected readout data, positions
and/or orientations; (c) calculation of the necessary set of
projections, which are needed to allow a reliable
3D-reconstruction; (d) displaying the set or a subset thereof or
the information enabling to guide the surgeon to record the needed
projections; (e) 3D-reconstruction of a valid 3D-gamma emitting
image and/or the calculation of a corresponding quality value.
[0229] 38. A method for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to
embodiment 31, including: (a) at least one surgical instrument; and
(b) a second tracking system for tracking surgical instruments,
wherein the second tracking system is the same as the first
tracking system or communicates with the first tracking system,
such that the relative position and orientation of the surgical
instruments and of the reconstructed valid 3D-gamma emitting image
can be calculated and can be used for (a) guiding the instruments
to regions of high accumulation, (b) guiding the instruments away
from regions of high accumulation, (c) guiding the instruments to
regions of low accumulation, (d) guiding the instruments away from
regions of low accumulation, (e) simulating, at the tip of each
instrument, the radiation reading which would be given if each
instrument was a radiation detector, (f) displaying surgical
instruments on the display and/or (g) detecting and warning a
surgeon, if the validity of the images is lost because of the
invasion in the reconstructed volume by means of the
instruments.
[0230] 39. A method for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to
embodiment 35, wherein the relative position and orientation of
surgical instruments is used for (a) guiding the instruments to
regions of high accumulation, (b) guiding the instruments away from
regions of high accumulation, (c) guiding the instruments to
regions of low accumulation, (d) guiding the instruments away from
regions of low accumulation, (e) calculating the radiation readings
that surgical instruments at their given positions and orientations
would measure if they were used as radiation detectors, (f)
displaying the surgical instruments in co-registered form with the
reconstructed valid 3D-gamma emitting images on the display, and/or
(g) for detecting and for warning the surgeon if the validity of
the images is lost by the invasion in the reconstructed volume by
means of the instruments.
[0231] 40. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to any
of the preceding or following embodiments, further including: (a) a
sensor for monitoring the respiration and the heart signal of a
patient, wherein the sensor communicates with a data processing
unit; (b) a sensor for determining the position and orientation
and/or the deformation of the part of the body which is imaged with
the system that communicates with a data processing unit, and/or
(c) tracking markings placed on or in the body part that is imaged
with the system and a third tracking system, wherein the third
tracking system is the same as the first or the second tracking
system or communicates with the first or second tracking system or
communicates with the data processing units, such that each reading
of the radiation detector, of the position and orientation and/or
deformation can be calculated in the relation to the body part that
is imaged or such that a phase label can be assigned to these with
respect to the movement and/or the deformation cycles for allowing
movement and/or deformation compensation in the reconstruction
and/or the display.
[0232] 41. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to any
of the preceding or following embodiments, further including: (a)
monitoring the respiration or a heart signal of the patient, (b)
monitoring the position and orientation and/or the deformation of
the body part that is imaged with the system, and/or (c) tracking
the markings which are placed on or in the body part imaged with a
system such that each reading of the radiation detector, position
and orientation and/or deformation can be calculated relative to
the body part that is imaged, or such that a phase label can be
assigned thereto with respect to the movement and/or the
deformation cycle for allowing movement and/or deformation
compensation in the reconstruction and/or the display.
[0233] 42. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to any
of the preceding or following embodiments, further including: (a) a
display of virtual reality and/or (b) a display of augmented
reality, such that the reconstructed valid 3D-gamma emitting image
can be displayed in 3D in acoustical, visual, or haptic way, or in
a combined way, and/or in particular spatially registered with the
image geometry of any camera, including laparoscope cameras and
cameras based on surgical microscopes, optical and optically
transparent head-mounted displays, optical and optically
transparent stereoscopic surgical microscopes, optical and
optically transparent displays.
[0234] 43. A method for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to any
of the preceding or following embodiments, further including:
displaying the reconstructed valid 3D-gamma emitting image on (a) a
display of virtual reality and/or (b) a display of augmented
reality, such that the image can be displayed in 3D in visual,
acoustical, haptical or in a combined way, and/or in particular
spatially registered with the image geometry of any camera,
including laparoscope cameras and cameras based on surgical
microscopes, optical and optically transparent head mounted
displays, optical and optically transparent stereoscopic surgical
microscopes, optical and optically transparent displays.
[0235] 44. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to the
embodiments 31, 37, 39, or 41, further including: (a) at least one
3D imaging device and a fourth tracking system that determines the
position and orientation of the imaging device, and which is the
same as the first, second or third tracking system or communicates
with these and/or (b) at least one port for co-registered
3D-images, wherein the 3D imaging device, the fourth tracking
system and the port for co-registered 3D-images communicates with
the first and second data processing unit, such that the
reconstructed valid 3D-gamma emitting image can be displayed in
co-registered way with the 3D-images and/or can be used to execute
attenuation and/or scattering correction on the 3D-gamma emitting
images, which are for example ultrasonic images, x-ray based
images, magnetic resonance tomography images, optical images,
contrast-enhanced ultrasonic images, contrast-enhanced x-ray based
images, functional magnetic resonance tomography images, dye-based
optical images, fluorescence images, reflection images,
auto-fluorescence images, etc.
[0236] 45. A method for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to any
of the preceding or following embodiments, further including: (a)
co-registered acquisition of anatomical or functional images that
stem from at least one 3D device and/or (b) use of previously
acquired co-registered 3D images that stem from at least one 3D
image generating device, such that the reconstructed valid 3D-gamma
emitting images can be displayed in co-registered way with the 3D
images and/or such that the 3D-gamma emitting images can be
corrected with respect to attenuation and/or scattering by use of
3D images.
[0237] 46. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery, preferably by use of radiation detectors,
according to any of the preceding or following embodiments, further
including: (a) a memory system for the involved information which
communicates with a first and second data processing unit and/or
(b) a third data processing unit which communicates with a first
and second data processing unit, such that the full information or
a part thereof are stored as documentation material and/or an
automatic report of the procedure is generated.
[0238] 47. A method for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors according to any
of the embodiments 36, 38, 40, 42, or 44, further including: (a)
storing the involved information and/or (b) automatically
generating documentation material.
[0239] 48. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors as described in
any of the preceding or following embodiments, further including: a
sensor and/or a further data processing unit, which can be the same
as the first data processing unit or can communicate with the first
data processing unit, for online computation or tracing errors in
the position and orientation of each of the tracked objects and/or
of the error in the readout data of the radiation readings.
[0240] 49. A method for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors as described in
any of the preceding or following embodiments, further including:
(a) online calculation or tracing of errors in the position and
orientation of each of the tracked objects and/or of the error in
the readout of each radiation reading; and (b) displaying the error
to assign a level of confidence and/or compensating the error to
use the gathered information according to the level of confidence
and to thus be able to compensate the errors.
[0241] 50. A device for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors substantially as
described herein and with reference to and/or as illustrated in the
appended drawings.
[0242] 51. A method for reliable intra-operative 3D-nuclear
imaging, 3D-visualization of radioactive spatial distributions and
image-guided surgery by use of radiation detectors substantially as
described herein and with reference to and/or as illustrated in the
appended drawings.
[0243] While the forgoing is directed to embodiments of the
invention, other and further embodiments of the invention can be
devised without departing from the scope of the invention set forth
in the following claims.
* * * * *