WO2006006096A1 - Image processing system for the processing of morphological and functional images - Google Patents

Image processing system for the processing of morphological and functional images Download PDF

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Publication number
WO2006006096A1
WO2006006096A1 PCT/IB2005/052154 IB2005052154W WO2006006096A1 WO 2006006096 A1 WO2006006096 A1 WO 2006006096A1 IB 2005052154 W IB2005052154 W IB 2005052154W WO 2006006096 A1 WO2006006096 A1 WO 2006006096A1
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images
image
morphological
functional
processing system
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PCT/IB2005/052154
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French (fr)
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Henning Braess
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Philips Intellectual Property & Standards Gmbh
Koninklijke Philips Electronics N. V.
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Publication of WO2006006096A1 publication Critical patent/WO2006006096A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/54—Control of apparatus or devices for radiation diagnosis
    • A61B6/541—Control of apparatus or devices for radiation diagnosis involving acquisition triggered by a physiological signal
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/026—Measuring blood flow
    • A61B5/0275—Measuring blood flow using tracers, e.g. dye dilution
    • A61B5/02755—Radioactive tracers
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5211—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data
    • A61B6/5229—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data combining image data of a patient, e.g. combining a functional image with an anatomical image
    • A61B6/5235—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data combining image data of a patient, e.g. combining a functional image with an anatomical image combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5211—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data
    • A61B6/5229—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data combining image data of a patient, e.g. combining a functional image with an anatomical image
    • A61B6/5247—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data combining image data of a patient, e.g. combining a functional image with an anatomical image combining images from an ionising-radiation diagnostic technique and a non-ionising radiation diagnostic technique, e.g. X-ray and ultrasound
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/03—Computed tomography [CT]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/50—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications
    • A61B6/503—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications for diagnosis of the heart
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/50—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications
    • A61B6/504—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications for diagnosis of blood vessels, e.g. by angiography

Definitions

  • Image processing system for the processing of morphological and functional images
  • the invention relates to a method and an image processing system for the processing of morphological and functional images of a body volume and a record carrier with software to carry out said method.
  • PET Positron Emission Tomography
  • TACs time-activity curves
  • compartment models biological models of the tracer metabolism
  • kinetic modeling requires the knowledge of the tracer concentration in the arterial blood.
  • the first possibility is to use a PET image of the left ventricle (which contains arterial blood) to deduce the tracer concentration in the blood pool.
  • the second possibility is to take blood samples and to measure the tracer concentration in the samples.
  • an image processing system which allows the registration of a CT image that reveals morphological information about the coronary arteries with a PET image that contains functional information thereof. After registration, the images can be simultaneously displayed in a matching way in order to allow a physician an easy evaluation.
  • the image processing system is adapted to process morphological images and functional images of a (particularly biological/human) body volume.
  • the morphological images reveal geometrical information about the internal structures or anatomy of the body volume and may particularly be CT images.
  • the functional images reveal spatially resolved information about certain functional aspects of said body volume and may particularly be PET images that show the activity of a radioactive tracer.
  • the image processing system comprises the following components: a) A registration module for the registration of a given morphological image with a given functional image. b) A segmentation module for the segmentation of at least one region of interest in the aforementioned morphological image. c) An evaluation module for the evaluation of said region of interest in the functional image. Due to the registration between the morphological and the functional image, the region of interest determined by the segmentation module can be located in the functional image and thus be evaluated by the evaluation module.
  • the image processing system allows an evaluation of functional images of a body volume in certain regions of interest, wherein said regions are determined with the help of geometrically accurate morphological images.
  • the image processing can easily be integrated into a medical workflow because it does not require the interaction of a user but applies automatic segmentation algorithms known in the art.
  • a transfer of the segmentation results obtained in the morphological images, i.e. the region of interest, is achieved by the registration of morphological and functional images.
  • the registration module may use any suited registration algorithm that allows the mutual association of image points (pixel or voxels) in the different images which represent the same point of the imaged object.
  • the registration module is adapted to register a morphological image and a functional image based on predetermined imaging parameters of said images.
  • the imaging parameters may particularly describe the coordinates of each image point with respect to the imaging device that was used for the generation of said image. If then the position of the two imaging devices relative to each other is known, too, registration of the images generated by the devices can be achieved by straightforward coordinate transformations.
  • the result of the registration procedure is a mapping of the morphological image onto the functional image (or vice versa). This mapping may particularly be a rigid registration, namely a shift and/or a rotation. In more complicated cases, the mapping may imply a scaling or distortions ("warping").
  • the segmentation module is adapted to segment different tissues and/or organs in a morphological image of a biological body volume. If the segmentation module is for example adapted to segment the left ventricle of the heart in a CT image, the concentration of a tracer in arterial blood may be determined from the corresponding PET image. Similarly, the segmentation of the cerebellum in a CT image of the head can be used to obtain PET data in a reference tissue. Moreover, the segmentation of certain tissues like the myocardium can be used in order to locate target tissues for the evaluation of compartment models based on PET images.
  • the evaluation module is adapted to generate temporal courses of a parameter from the regions of interest of functional images that belong to a temporal sequence of functional images. If the functional images are for example PET images of a body volume, they reveal the activity and thus concentration of a radioactive tracer. Measurements of activity in always the same body region in a temporal sequence of PET images can then be used to reconstruct the time-activity curves (TACs) of the tracer in said region.
  • TACs time-activity curves
  • the image processing system comprises a gating module for selecting morphological images and/or functional images which correspond to a predetermined state of the body volume.
  • Said state may particularly be the phase of heart beat and/or the phase of respiration of a patient.
  • Heart beat and respiration are important examples of cyclic changes that take place in the body of a patient and cause motions and deformations of the observed body structures, for example of the coronary arteries. If morphological and functional images shall be compared that were generated at different times, the accuracy can be improved if only such images are compared which belong to
  • the gating module therefore provides motion compensated images.
  • the image processing system may additionally comprise a recording unit for measuring a parameter that characterizes the aforementioned state of the body volume. The parameter can then be recorded simultaneously to the generation of morphological and functional images in order to index or classify the images with respect to the state of the body volume.
  • the recording unit may particularly be an ECG device that allows the characterization of heart beat by an electrocardiogram (ECG).
  • ECG electrocardiogram
  • the recording unit may be a sensor for recording the state of respiration.
  • the image processing system optionally comprises a display unit for the display of information like morphological images, functional images and/or the results produced by the evaluation module. The graphical representation of data on a display unit allows a user an intuitive and quick access to the information.
  • the image processing system may further comprise at least one imaging system for the generation of the morphological images and/or functional images that shall be processed.
  • Said imaging system may particularly be selected among the group consisting of an ultrasound (US), an X-ray, a CT (Computed Tomography), an MRI (Magnetic Resonance Imaging), a PET (Positron Emission Tomography), or a SPECT (Single Photon Emission Computed Tomography) device, wherein the latter two devices are preferably used for the generation of functional images.
  • the invention also relates to a method for the processing of morphological and functional images of a body volume, comprising the steps of a) registration of a morphological image with a functional image; b) segmentation of at least one region of interest in said morphological image; c) evaluation of said region of interest in the functional image.
  • the invention comprises a record carrier, for example a floppy disk, a hard disk, or a compact disc (CD), on which a computer program for the processing of morphological images and functional images of a body volume is stored, wherein said program is adapted to execute a method of the aforementioned kind.
  • the method and the record carrier have similar features like the image processing system that was described above. For more information on details, advantages and further developments of them reference is therefore made to the description of said system.
  • the imaging system 10 that is depicted in the left part of the Figure comprises a CT device 11 for generating two-dimensional or three-dimensional sectional images I of the body of a patient 1. Moreover, it comprises a PET device 12 for generating PET images J that reveal the activity (and therefore concentration) of a tracer injected into the vessel system of the patient 1.
  • Typical examples for tracers are S2 Rubidium, 15 O-Water, or 13 N-Ammonia (for perfusion studies of the heart), FDG (for studies of myocardial viability), and 11 -C-HED (for studies of cardiac neuro-receptor density).
  • the system further comprises an ECG recording 13 that is coupled to the patient 1 via electrodes in a conventional way and that is adapted to record the electrical activity of the heart of the patient.
  • the system may comprise a unit for monitoring the respiration of the patient, for example a chest belt with pressure sensors. Such a unit is not shown in the Figure for reasons of clarity, and its use is analogous to that of the ECG recording unit 13.
  • the system further comprises a data processing unit 20 (for example a workstation) that comprises the usual hardware components like central processing unit (CPU), memory (RAM, ROM, hard disc, CD etc.), I/O interfaces, and peripheral devices together with the necessary software to accomplish the required functions.
  • a data processing unit 20 for example a workstation
  • CPU central processing unit
  • RAM random access memory
  • ROM read-only memory
  • HDD hard disc
  • CD etc. compact flash memory
  • I/O interfaces I/O interfaces
  • the first module of the data processing unit 20 is a gating module 22 that comprises I/O interfaces for the (bidirectional) communication with the imaging system 10 and memory for the storage of CT images I, PET images J, and electrocardiographical data ECG that are the generated by the components 11, 12, and 13, respectively, of the imaging system 10.
  • the gating module 21 is adapted to select from a temporal sequence 21 of PET images J those images J 0 that belong to a predetermined phase of the heart beat.
  • the gating module 21 is adapted to control the CT system 11 such that CT images I are only generated during the aforementioned phases of heart beat, yielding selected CT images I 0 .
  • the gating module 21 defines a gate in the heart cycle during which generated PET images J are accepted and the generation of CT images I is initiated, while images are sorted out or not generated during the other phases of heart beat.
  • a similar gating function can optionally be provided for the respiration phase.
  • the PET images Jo and the CT images Io that are selected by the gating module 22 as belonging to the same phase of the heart beat are then passed on to a registration module 23 where they are registered. If all the imaging parameters of the CT system 11 and PET device 12 are available and their relative positions are known, the registration can be calculated from these data. In principle, however, any registration algorithm known from the state of the art may be applied in module 23. Suitable examples may be found in the US 5 871 013 which is incorporated into the present application by reference. As a result of the registration, the image coordinates of an object point in one of the images (for example Io) can be transformed into the image coordinates of this point in the other image Jo.
  • segmentation denotes the process of classifying picture elements (pixels or voxels) of an image according to their membership to a certain component of the imaged object.
  • segmentation may particularly determine the site ROI of the left ventricle of the heart of the patient 1. Due to the high quality of the CT image I 0 with respect to the anatomy of the patient, the result of the segmentation is very accurate. With the help of the registration determined in module 23, the region of interest ROI determined in the CT image I 0 may then be transferred to the corresponding PET image Jo.
  • a subsequent evaluation module 25 may then evaluate the PET image J 0 in the region of interest ROI in order to obtain functional information from a certain anatomical region.
  • the evaluation module 25 may for example determine the measured activity at the centre of the region of interest ROI or the mean activity in said region. Thus it is for example possible to determine the concentration of a tracer in arterial blood noninvasively and with high reliability.
  • the course of the activity A in the left ventricle may be determined over time t, yielding a curve C that can for example serve as an input function in compartment models.
  • the Figure further shows a monitor 30 that is coupled to the computer 20 and on which images and results of the evaluation can be displayed.
  • a monitor 30 that is coupled to the computer 20 and on which images and results of the evaluation can be displayed.
  • the cerebellum is a suitable reference tissue. According to another application of the imaging system the cerebellum is therefore segmented automatically from the CT- image and the corresponding region is determined in the PET-image by co-registration. This application typically does not need motion compensation, cardiac or respiratory gating.
  • the automatic segmentation can also be used to decide in which area compartment modeling is performed (e.g. myocardium) and in which area no modeling is performed (blood pool and background).
  • area compartment modeling e.g. myocardium
  • area no modeling e.g. blood pool and background

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Abstract

The invention relates to a method and a system for the processing of morphological and functional images of a body volume, particularly of CT-images (I, lo) and PET-images (J, Jo). The images are preferably gated with respect to heart beat (ECG) and/or respiration in order to show comparable states of body motion. After registration (23), a region of interest (ROI) is segmented in a morphological image (lo), and the functional image (Jo) is evaluated in said region. If the region of interest (ROI) is for example the left ventricle of a heart, time activity curves (C) in the arterial blood of a patient may be determined from corresponding PET-image sequences.

Description

Image processing system for the processing of morphological and functional images
The invention relates to a method and an image processing system for the processing of morphological and functional images of a body volume and a record carrier with software to carry out said method.
PET (Positron Emission Tomography) can be utilized to measure the time-dependent concentration of a radioactive tracer in the human body. These measurements are called time-activity curves (TACs). When these TACs are combined with certain biological models of the tracer metabolism (so-called compartment models) they can be used to deduce certain biological quantities, such as the tissue perfusion. This kind of biological modeling or "kinetic modeling" requires the knowledge of the tracer concentration in the arterial blood. There are two possibilities to measure the tracer concentration in the blood pool. The first possibility is to use a PET image of the left ventricle (which contains arterial blood) to deduce the tracer concentration in the blood pool. The second possibility is to take blood samples and to measure the tracer concentration in the samples.
For quantitative perfusion imaging one has to acquire a temporal sequence of PET-images and a measurement of the concentration of the tracer in the arterial blood pool. According to the first possibility mentioned above, the user has to indicate a region of interest (ROI) in the PET-image that covers either the left ventricle or some part of the aorta. The average gray value in this region of interest corresponds to the tracer concentration in the arterial blood pool. There are two drawbacks to this procedure: First, the accuracy of the measurement is corrupted by cardiac and respiratory motion. The more important second drawback is that the procedure depends critically on user-interaction, which is not very compatible with the medical workflow.
From the US 2004/0044282 Al an image processing system is known which allows the registration of a CT image that reveals morphological information about the coronary arteries with a PET image that contains functional information thereof. After registration, the images can be simultaneously displayed in a matching way in order to allow a physician an easy evaluation.
Based on this situation it was an object of the present invention to provide means for the versatile processing of morphological and functional images that allow an easy integration into a the medical workflow.
This object is achieved by an image processing system according to claim 1, a method according to claim 9, and a record carrier according to claim 10. Preferred embodiments are disclosed in the dependent claims.
The image processing system according to the present invention is adapted to process morphological images and functional images of a (particularly biological/human) body volume. The morphological images reveal geometrical information about the internal structures or anatomy of the body volume and may particularly be CT images. The functional images reveal spatially resolved information about certain functional aspects of said body volume and may particularly be PET images that show the activity of a radioactive tracer. The image processing system comprises the following components: a) A registration module for the registration of a given morphological image with a given functional image. b) A segmentation module for the segmentation of at least one region of interest in the aforementioned morphological image. c) An evaluation module for the evaluation of said region of interest in the functional image. Due to the registration between the morphological and the functional image, the region of interest determined by the segmentation module can be located in the functional image and thus be evaluated by the evaluation module.
The image processing system allows an evaluation of functional images of a body volume in certain regions of interest, wherein said regions are determined with the help of geometrically accurate morphological images. The image processing can easily be integrated into a medical workflow because it does not require the interaction of a user but applies automatic segmentation algorithms known in the art. A transfer of the segmentation results obtained in the morphological images, i.e. the region of interest, is achieved by the registration of morphological and functional images. The registration module may use any suited registration algorithm that allows the mutual association of image points (pixel or voxels) in the different images which represent the same point of the imaged object. According to a preferred embodiment, the registration module is adapted to register a morphological image and a functional image based on predetermined imaging parameters of said images. The imaging parameters may particularly describe the coordinates of each image point with respect to the imaging device that was used for the generation of said image. If then the position of the two imaging devices relative to each other is known, too, registration of the images generated by the devices can be achieved by straightforward coordinate transformations. The result of the registration procedure is a mapping of the morphological image onto the functional image (or vice versa). This mapping may particularly be a rigid registration, namely a shift and/or a rotation. In more complicated cases, the mapping may imply a scaling or distortions ("warping").
According to a preferred embodiment, the segmentation module is adapted to segment different tissues and/or organs in a morphological image of a biological body volume. If the segmentation module is for example adapted to segment the left ventricle of the heart in a CT image, the concentration of a tracer in arterial blood may be determined from the corresponding PET image. Similarly, the segmentation of the cerebellum in a CT image of the head can be used to obtain PET data in a reference tissue. Moreover, the segmentation of certain tissues like the myocardium can be used in order to locate target tissues for the evaluation of compartment models based on PET images.
According to another preferred embodiment of the invention, the evaluation module is adapted to generate temporal courses of a parameter from the regions of interest of functional images that belong to a temporal sequence of functional images. If the functional images are for example PET images of a body volume, they reveal the activity and thus concentration of a radioactive tracer. Measurements of activity in always the same body region in a temporal sequence of PET images can then be used to reconstruct the time-activity curves (TACs) of the tracer in said region.
According to a further development of the invention, the image processing system comprises a gating module for selecting morphological images and/or functional images which correspond to a predetermined state of the body volume. Said state may particularly be the phase of heart beat and/or the phase of respiration of a patient. Heart beat and respiration are important examples of cyclic changes that take place in the body of a patient and cause motions and deformations of the observed body structures, for example of the coronary arteries. If morphological and functional images shall be compared that were generated at different times, the accuracy can be improved if only such images are compared which belong to
(approximately) the same phase of heart beat and/or respiration. The gating module therefore provides motion compensated images.
The image processing system may additionally comprise a recording unit for measuring a parameter that characterizes the aforementioned state of the body volume. The parameter can then be recorded simultaneously to the generation of morphological and functional images in order to index or classify the images with respect to the state of the body volume. The recording unit may particularly be an ECG device that allows the characterization of heart beat by an electrocardiogram (ECG). Furthermore, the recording unit may be a sensor for recording the state of respiration. The image processing system optionally comprises a display unit for the display of information like morphological images, functional images and/or the results produced by the evaluation module. The graphical representation of data on a display unit allows a user an intuitive and quick access to the information.
The image processing system may further comprise at least one imaging system for the generation of the morphological images and/or functional images that shall be processed. Said imaging system may particularly be selected among the group consisting of an ultrasound (US), an X-ray, a CT (Computed Tomography), an MRI (Magnetic Resonance Imaging), a PET (Positron Emission Tomography), or a SPECT (Single Photon Emission Computed Tomography) device, wherein the latter two devices are preferably used for the generation of functional images.
The invention also relates to a method for the processing of morphological and functional images of a body volume, comprising the steps of a) registration of a morphological image with a functional image; b) segmentation of at least one region of interest in said morphological image; c) evaluation of said region of interest in the functional image. Finally, the invention comprises a record carrier, for example a floppy disk, a hard disk, or a compact disc (CD), on which a computer program for the processing of morphological images and functional images of a body volume is stored, wherein said program is adapted to execute a method of the aforementioned kind.
The method and the record carrier have similar features like the image processing system that was described above. For more information on details, advantages and further developments of them reference is therefore made to the description of said system.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. In the following the invention is described by way of example with the help of the accompanying drawing which schematically shows the components of a system according to the present invention for the processing of CT and PET images.
The imaging system 10 that is depicted in the left part of the Figure comprises a CT device 11 for generating two-dimensional or three-dimensional sectional images I of the body of a patient 1. Moreover, it comprises a PET device 12 for generating PET images J that reveal the activity (and therefore concentration) of a tracer injected into the vessel system of the patient 1. Typical examples for tracers are S2Rubidium, 15O-Water, or 13N-Ammonia (for perfusion studies of the heart), FDG (for studies of myocardial viability), and 11 -C-HED (for studies of cardiac neuro-receptor density).
The system further comprises an ECG recording 13 that is coupled to the patient 1 via electrodes in a conventional way and that is adapted to record the electrical activity of the heart of the patient. Additionally or alternatively, the system may comprise a unit for monitoring the respiration of the patient, for example a chest belt with pressure sensors. Such a unit is not shown in the Figure for reasons of clarity, and its use is analogous to that of the ECG recording unit 13.
The system further comprises a data processing unit 20 (for example a workstation) that comprises the usual hardware components like central processing unit (CPU), memory (RAM, ROM, hard disc, CD etc.), I/O interfaces, and peripheral devices together with the necessary software to accomplish the required functions. The Figure depicts different functional modules 22-25 of the data processing unit which are realized on the computer hardware with appropriate software.
The first module of the data processing unit 20 is a gating module 22 that comprises I/O interfaces for the (bidirectional) communication with the imaging system 10 and memory for the storage of CT images I, PET images J, and electrocardiographical data ECG that are the generated by the components 11, 12, and 13, respectively, of the imaging system 10. The gating module 21 is adapted to select from a temporal sequence 21 of PET images J those images J0 that belong to a predetermined phase of the heart beat. Moreover, the gating module 21 is adapted to control the CT system 11 such that CT images I are only generated during the aforementioned phases of heart beat, yielding selected CT images I0. In other words, the gating module 21 defines a gate in the heart cycle during which generated PET images J are accepted and the generation of CT images I is initiated, while images are sorted out or not generated during the other phases of heart beat. A similar gating function can optionally be provided for the respiration phase.
The PET images Jo and the CT images Io that are selected by the gating module 22 as belonging to the same phase of the heart beat are then passed on to a registration module 23 where they are registered. If all the imaging parameters of the CT system 11 and PET device 12 are available and their relative positions are known, the registration can be calculated from these data. In principle, however, any registration algorithm known from the state of the art may be applied in module 23. Suitable examples may be found in the US 5 871 013 which is incorporated into the present application by reference. As a result of the registration, the image coordinates of an object point in one of the images (for example Io) can be transformed into the image coordinates of this point in the other image Jo.
The next component to which the selected images Io, Jo are passed on is a segmentation module 24, in which a segmentation of the morphological image Io is performed. As usual in the art of image processing, "segmentation" denotes the process of classifying picture elements (pixels or voxels) of an image according to their membership to a certain component of the imaged object. In the example shown in the Figure, the segmentation may particularly determine the site ROI of the left ventricle of the heart of the patient 1. Due to the high quality of the CT image I0 with respect to the anatomy of the patient, the result of the segmentation is very accurate. With the help of the registration determined in module 23, the region of interest ROI determined in the CT image I0 may then be transferred to the corresponding PET image Jo.
A subsequent evaluation module 25 may then evaluate the PET image J0 in the region of interest ROI in order to obtain functional information from a certain anatomical region. The evaluation module 25 may for example determine the measured activity at the centre of the region of interest ROI or the mean activity in said region. Thus it is for example possible to determine the concentration of a tracer in arterial blood noninvasively and with high reliability.
If a temporal sequence of several PET images J0 is processed in the way described above (either in combination with one static CT image or with a parallel sequence of CT images), the course of the activity A in the left ventricle may be determined over time t, yielding a curve C that can for example serve as an input function in compartment models.
The Figure further shows a monitor 30 that is coupled to the computer 20 and on which images and results of the evaluation can be displayed. Thus it is particularly possible to display a CT image I0 of the heart together with an inserted window showing the activity A over time in the left ventricle.
A preferred application of the described imaging system comprises an automated segmentation of the CT image I0 of the heart for the identification of the left ventricle and a gating to avoid motion artifacts according to the following steps: - acquire a sequence of PET-images Jo with cardiac and respiratory gating; acquire a CT image I0 of the heart in one breath-hold with cardiac gating; use any segmentation algorithm to identify the left ventricle (=ROI) in the CT-image I0; use any technique that defines the corresponding ROI in the PET-images Jo (for example rigid registration); utilize the ROI in the PET images Jo to measure the tracer concentration in the arterial blood pool, i.e. the input function for a compartment model.
Instead of obtaining the input function from the blood pool, one can also measure the tracer activity in a reference tissue. In the case of many neurological studies the cerebellum is a suitable reference tissue. According to another application of the imaging system the cerebellum is therefore segmented automatically from the CT- image and the corresponding region is determined in the PET-image by co-registration. This application typically does not need motion compensation, cardiac or respiratory gating.
The automatic segmentation can also be used to decide in which area compartment modeling is performed (e.g. myocardium) and in which area no modeling is performed (blood pool and background). When modeling is performed only in the area of the myocardium, the calculation time is much shorter. Finally it is pointed out that in the present application the term
"comprising" does not exclude other elements or steps, that "a" or "an" does not exclude a plurality, and that a single processor or other unit may fulfill the functions of several means. Moreover, reference signs in the claims shall not be construed as limiting their scope.

Claims

CLAIMS:
1. An image processing system (10, 20, 30) for the processing of morphological images (I, Io) and functional images (J, Jo) of a body volume, the system comprising: a) a registration module (23) for the registration of a morphological image (I0) with a functional image (Jo); b) a segmentation module (24) for the segmentation of at least one region of interest (ROI) in said morphological image (Io); c) an evaluation module (25) for the evaluation of said region of interest (ROI) in the functional image (J0).
2. The image processing system of claim 1, characterized in that the registration module (23) is adapted to register a morphological image (Io) and a functional image (J0) based on predetermined imaging parameters of said images.
3. The image processing system of claim 1, characterized in that the segmentation module (24) is adapted to segment different tissues or organs in the morphological image (Io), particularly a ventricle of a heart, the myocardium, or the cerebellum.
4. The image processing system of claim 1, characterized in that the evaluation module (25) is adapted to determine temporal courses (C) of a parameter from the regions of interest (ROI) of functional images (Jo) that belong to a temporal sequence of images.
5. The image processing system according to claim 1, characterized in that it comprises a gating module (22) for selecting morphological images (Io) and/or functional images (Jo) which correspond to a predetermined state of the body volume, particularly to the phase of heart beat and/or of respiration.
6. The image processing system according to claim 5, characterized in that it comprises a recording unit (13) for measuring a parameter (ECG) that characterizes said state of the body volume.
7. The image processing system according to claim 1, characterized in that it comprises a display unit (30) for the display of morphological images (I, I0), functional images (J, Jo) and/or evaluation results (C).
8. The image processing system according to claim 1, characterized in that it comprises an imaging system (10) for the generation of the morphological images (I, I0) and/or of the functional images (J, J0), particularly an US, X-ray, CT, MRI, PET, and/or SPECT device.
9. A method for the processing of morphological images (I, I0) and functional images (J, J0) of a body volume, comprising the steps of a) registration of a morphological image (I0) with a functional image (Jo); b) segmentation of at least one region of interest (ROI) in said morphological image (I0); c) evaluation of said region of interest (ROI) in the functional image (Jo).
10. A record carrier on which a computer program for the processing of morphological images (I, Io) and functional images (J, Jo) of a body volume is stored, said program being adapted to execute a method according to claim 9.
PCT/IB2005/052154 2004-07-09 2005-06-29 Image processing system for the processing of morphological and functional images WO2006006096A1 (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1891899A1 (en) * 2006-08-25 2008-02-27 Multi Magnetics Incorporated Method and system for performing local tomography
CN102067176A (en) * 2008-06-18 2011-05-18 皇家飞利浦电子股份有限公司 Radiological imaging incorporating local motion monitoring, correction, and assessment
CN103720474A (en) * 2012-10-12 2014-04-16 西门子公司 Inspection parameter calculating
JP2015110045A (en) * 2015-02-17 2015-06-18 株式会社東芝 Medical image diagnostic apparatus and medical image processing device
CN111402356A (en) * 2020-03-19 2020-07-10 上海联影医疗科技有限公司 Parameter imaging input function extraction method and device and computer equipment
US11688071B2 (en) 2020-03-19 2023-06-27 Shanghai United Imaging Healthcare Co., Ltd. Systems and methods for image reconstruction and processing

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5024230A (en) * 1988-11-23 1991-06-18 Picker International, Inc. Dual flow/lambda display for xenon enhanced tomography
US5435310A (en) * 1993-06-23 1995-07-25 University Of Washington Determining cardiac wall thickness and motion by imaging and three-dimensional modeling
US5803914A (en) * 1993-04-15 1998-09-08 Adac Laboratories Method and apparatus for displaying data in a medical imaging system
US6415048B1 (en) * 1993-10-12 2002-07-02 Schneider Medical Technologies, Inc. Compositional analysis system
US20030004584A1 (en) * 2001-06-27 2003-01-02 Hallett Jeffrey A. User interface for a gamma camera which acquires multiple simultaneous data sets

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5024230A (en) * 1988-11-23 1991-06-18 Picker International, Inc. Dual flow/lambda display for xenon enhanced tomography
US5803914A (en) * 1993-04-15 1998-09-08 Adac Laboratories Method and apparatus for displaying data in a medical imaging system
US5435310A (en) * 1993-06-23 1995-07-25 University Of Washington Determining cardiac wall thickness and motion by imaging and three-dimensional modeling
US6415048B1 (en) * 1993-10-12 2002-07-02 Schneider Medical Technologies, Inc. Compositional analysis system
US20030004584A1 (en) * 2001-06-27 2003-01-02 Hallett Jeffrey A. User interface for a gamma camera which acquires multiple simultaneous data sets

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1891899A1 (en) * 2006-08-25 2008-02-27 Multi Magnetics Incorporated Method and system for performing local tomography
CN102067176A (en) * 2008-06-18 2011-05-18 皇家飞利浦电子股份有限公司 Radiological imaging incorporating local motion monitoring, correction, and assessment
CN103720474A (en) * 2012-10-12 2014-04-16 西门子公司 Inspection parameter calculating
JP2015110045A (en) * 2015-02-17 2015-06-18 株式会社東芝 Medical image diagnostic apparatus and medical image processing device
CN111402356A (en) * 2020-03-19 2020-07-10 上海联影医疗科技有限公司 Parameter imaging input function extraction method and device and computer equipment
US11688071B2 (en) 2020-03-19 2023-06-27 Shanghai United Imaging Healthcare Co., Ltd. Systems and methods for image reconstruction and processing
CN111402356B (en) * 2020-03-19 2024-04-16 上海联影医疗科技股份有限公司 Parameter imaging input function extraction method and device and computer equipment

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