JP5345947B2 - Imaging system and imaging method for imaging an object - Google Patents

Abstract

The invention relates to an imaging system for imaging an object, wherein the imaging system is adapted for scanning the object in accordance with a scan parameter. The imaging system comprises a projection image generation unit (15) for generating a two-dimensional projection image of the object. A model provision unit (16) provides a three-dimensional model of the object, and a registration unit (17) registers the three-dimensional model with the two-dimensional project ion image. A scan parameter determination unit (18) determines the scan parameter from the registered three-dimensional model.

Description

  The present invention relates to an imaging system, an imaging method, and a computer program for imaging an object. The present invention further relates to a scan parameter determination apparatus, a scan parameter determination method, and a computer program for determining a scan parameter.

  The computer tomography system is an imaging system that images an object. The computed tomography system has an X-ray source and a detection unit that move relative to an examination region where an object is placed. Detection values depending on the radiation after passing through the object are collected, and an image of the object is reconstructed using the collected detection values. The x-ray source typically irradiates only the portion of the object that must be irradiated to obtain a detection value sufficient to reconstruct the desired region of interest. The region of interest is generally defined manually. In order to manually define the region of interest, a two-dimensional projection image is generated and displayed on the monitor. Then, the user defines a region of interest on the two-dimensional projection image using a graphical user interface. The two-dimensional projection image is generated by linearly moving the object table on which the object is placed and irradiating the object with the radiation of the X-ray source. The X-ray source is not rotated during the generation of the two-dimensional projection image.

  This region-of-interest determination method has a drawback in that a plurality of structures of overlapping objects cannot be identified in the two-dimensional projection image in the projection direction, thus degrading the quality of determination of the region of interest.

  The present invention aims to provide an imaging system for imaging an object in which the determination of scan parameters such as a region of interest is improved.

In a first aspect of the invention, an imaging system for imaging an object is presented that is adapted to scan the object according to scan parameters. The imaging system is:
A projection image generation unit for generating a two-dimensional projection image of the object;
-A model providing unit that provides a 3D model of the object;
A registration unit that aligns the 3D model with the 2D projection image;
-A scan parameter determination unit for determining scan parameters from the matched model;
Have

  The present invention is based on the idea that since the model is a three-dimensional model, a plurality of structures that overlap in the projection direction of the projected image can be identified in the three-dimensional model, and the determination of scan parameters is improved.

  The imaging system preferably further comprises a display unit for displaying at least one of registration between the 2D projection image and the 3D model and the determined scan parameters. This allows the user to monitor registration between the 2D projection image and the 3D model and / or monitor scan parameter determination.

  More preferably, the imaging system comprises a change unit that allows a user to change at least one of registration between the 2D projection image and the 3D model and the determined scan parameters. This allows the user to correct at least one of registration between the 2D projection image and the 3D model and the determined scan parameter, further improving the determination of the scan parameter.

  More preferably, the imaging system has a motion determining unit for determining the motion of the object, the model providing unit is adapted to provide a moving three-dimensional model of the object, and the registration unit is determined The motion of the object is used to adapt the moving 3D model to the 2D projection image, and the scan parameter determination unit is adapted to determine scan parameters from the aligned moving 3D model.

  During the generation of the 2D projection image, the object motion is taken into account during the alignment of the 2D projection image with the 3D model and the determination of the scan parameters from the aligned 3D model, so it should be scanned Even if the object is a moving object, the determination of the scan parameters is improved.

  In one embodiment, the registration unit is adapted to use registration features for registration that are detectable in the 2D projection image and in the 3D model. The scan parameter determination unit then uses the scan parameter determination feature of the 3D model to determine the scan parameter from the matched 3D model. This makes it possible to optimize the registration feature for registration and the scan parameter determination feature for determining the scan parameter independently of each other. Thereby, registration quality and scan parameter determination quality are further improved.

  Preferably, the three-dimensional model of the object not only has the object itself, but also has further objects or components, in particular registration features. For example, if the object to be imaged is a patient's heart, the object model preferably has a plurality of objects or components located not only in the heart but also in the human patient's chest region. That is, if the object to be imaged is the patient's heart, the heart model is preferably the patient's heart and additional components in the chest region, such as the spine and ribs that can be used as registration features. Or a chest model including an object.

  Preferably, the model providing unit is adapted to adapt the 3D model to the 2D projection image. The three-dimensional model can be deformed, for example, translated, rotated, contracted, and / or enlarged to match the projected image as closely as possible. For example, a similarity measure such as a sum or correlation of absolute differences can be used, and the 3D model minimizes the similarity measure given to the 2D projection image and the simulated 2D projection image. It can be modified as follows. Here, the simulated two-dimensional projection image may be, for example, that simulated by forwardly projecting the deformed three-dimensional model within the geometric configuration of the projection of the given two-dimensional projection image. Since the 3D model is applied to a 2D projection image showing the projection of the object to be scanned at the present time, the 3D model is applied to each object, not a standard object. This adapted three-dimensional model is a three-dimensional model specific to each object, and scan parameters are determined using it, so that the determination of scan parameters is further improved.

In a further aspect of the invention, a scan parameter determination device for determining scan parameters is provided that can be used by an imaging system that scans an object according to scan parameters. The scan parameter determination apparatus is given a two-dimensional projection image of the object generated by the projection image generation unit. The scan parameter determination device is:
-A model providing unit that provides a 3D model of the object;
A registration unit that aligns the 3D model with the 2D projection image;
A scan parameter determination unit for determining scan parameters from the matched 3D model;
Have

In a further aspect of the invention, an imaging method for imaging an object adapted to scan the object according to scan parameters is presented. The imaging method is:
-Generating a two-dimensional projection image of the object by the projection image generation unit;
-Providing a 3D model of the object by the model providing unit;
-Aligning the 3D model with the 2D projection image by means of a registration unit;
-Determining scan parameters from the matched three-dimensional model by a scan parameter determination unit;
Have

In a further aspect of the invention, there is provided a scan parameter determination method for determining a scan parameter that can be used by an imaging system that scans an object according to the scan parameter. The scan parameter determination method is given a two-dimensional projection image of the object generated by the projection image generation unit. The scan parameter determination method is:
-Providing a 3D model of the object by the model providing unit;
-Aligning the 3D model with the 2D projection image by means of a registration unit;
-Determining scan parameters from the matched three-dimensional model by a scan parameter determination unit;
Have

In a further aspect of the present invention, a computer program for imaging an object is provided. The computer program has program code that, when executed on a computer that controls the imaging system according to claim 1, causes the computer to execute the steps of the imaging method according to claim 5 .

In a further aspect of the invention, a computer program for determining scan parameters is provided. The computer program has program code that, when executed on a computer that controls the scan parameter determination device according to claim 4 , causes the computer to execute the steps of the scan parameter determination method according to claim 6 .

As will be appreciated, the imaging system according to claim 1, the imaging method of the scanning parameter determining apparatus, according to claim 5 according to claim 4, a computer program according to the computer program, and claim 8 according to claim 7, It has the same preferred embodiments as defined in the dependent claims and / or the same preferred embodiments.

  As will be appreciated, preferred embodiments of the invention may be a combination of, for example, two or more dependent claims and each independent claim.

These and further aspects of the invention will become apparent by reference to the embodiments described hereinafter.
1 schematically illustrates an imaging system according to the present invention. 1 schematically shows a scanning parameter determination device according to the present invention. FIG. 3 is a flowchart schematically showing an imaging method for imaging an object according to the present invention. 3 is a flowchart schematically showing a scan parameter determination method for determining a scan parameter according to the present invention.

  FIG. 1 shows an imaging system for imaging an object, which is a computed tomography system (CT system) in this embodiment. The CT system includes a gantry 1 that can rotate around a rotation axis R that extends parallel to the z direction. The gantry 1 is attached with a radiation source 2 which is an X-ray source 2 in this embodiment. The X-ray source 2 includes a collimator device 3 that forms a conical radiation beam 4 from the radiation generated by the X-ray source 2. The radiation traverses an object (not shown), such as a patient, in the examination region 5, which in this embodiment is cylindrical. After crossing the examination region 5, the X-ray beam 4 enters a detection unit 6 having a two-dimensional detection surface in this embodiment. The detection unit 6 is attached to the gantry 1.

  The imaging system includes a driving device having two motors 7 and 8. The gantry 1 can be rotated by a motor 7, preferably at a constant but adjustable angular speed. A motor 8 is provided for displacing an object such as a patient disposed on the patient table in the examination region 5 in parallel with the direction of the rotation axis R, that is, the direction of the z-axis. These motors 7 and 8 are controlled by the control unit 9 so that, for example, the radiation source 2 and the examination region 5 move relatively along the spiral trajectory. However, it is also possible that only the radiation source 2 is rotated without moving the examination region 5, that is, the radiation source 2 moves along a circular trajectory with respect to the examination region 5. In addition, the inspection region 5 including the object is moved in the direction parallel to the rotation axis R, that is, the z-axis direction, and the radiation source 2 is not rotated. That is, the radiation source 2 and the inspection region 5 are relatively aligned along the linear trajectory. It is also possible to move.

  In another embodiment, the collimator 3 may be adapted to form a fan-shaped beam and the detection unit 6 may be a one-dimensional detector.

  The control unit 9 is adapted to scan the object according to one or more scanning parameters during the collection of detection values that will be used to reconstruct the image of the object. In order to determine the scan parameters, the radiation source 2 and the examination region 5 move relatively along a linear trajectory, the detection values are collected by the detection unit 6, and the detection values are transmitted to the projection image generation unit 15. During the collection of these detection values, preferably the radiation source 2 is not rotated and the examination region 5 and thus the object is moved, for example, by moving the patient table on which the patient is placed in a parallel direction, ie parallel to the rotation axis R. , Parallel to the z direction, that is, parallel to the rotation axis. The projection image generation device 15 generates a two-dimensional projection image of the object and transmits the generated two-dimensional projection image to the scan parameter determination device 12.

  In more detail, the scan parameter determination device 12 shown in FIG. 2 includes a model providing unit 16 that provides a three-dimensional model of an object, and a registration unit 17 that aligns (registers) the three-dimensional model with a two-dimensional projection image. And a scan parameter determination unit 18 for determining a scan parameter from the matched three-dimensional model, and a user changes at least one of registration between the two-dimensional projection image and the three-dimensional model and the determined scan parameter And a change unit 19 which makes it possible to do this. The determined scan parameters and / or the three-dimensional matched model and the two-dimensional projection image can be displayed on the display 11. The scan parameters determined by the scan parameter determination unit 18 are transmitted to the control unit 9, which is determined to collect detection values that will be used to reconstruct the image of the object. Control the scanning of the object according to the scanning parameters.

  The detection values collected while the control unit 9 is controlling the imaging system according to the determined one or more scan parameters are provided to an image generating device 10 that generates an image of the object. The image generation device 10 reconstructs an image of the object using the collected detection values.

  The reconstructed image can finally be given to the display 11 displaying the image. The image generation device 10, the scan parameter determination device 12 and / or the projection image generation unit 15 are also preferably controlled by the control unit 9.

  The control unit 9 is connected to an input unit 20, such as a keyboard or mouse, which allows the user to select or select a desired scan in particular. For example, if there are multiple objects and a particular object is to be imaged, the user can input only a certain part of the object.

  In this embodiment, the CT system further comprises a motion determination unit 14 for determining the motion of the object. The motion determination unit 14 is, for example, an electrocardiograph that collects an electrocardiogram directly related to the patient's heart motion when the heart, or a portion of the heart, i.e. the region of interest, has to be imaged. Additionally or alternatively, the motion determination unit 14 may have a device for determining patient motion caused by breathing. The motion determination unit 14 can also be adapted to determine the motion of the object from the collected detection values that will be used to reconstruct the image of the object. The image of the object can then also image a part of the object, i.e. the region of interest of the object.

  Next, an embodiment of an imaging method for imaging an object according to the present invention will be described in more detail with reference to the flowchart shown in FIG.

  At step 101, the scan type to be performed is given. For example, the user defines the scan type by inputting a corresponding input signal to the control unit 9 using the input device 20. The user can specify that certain organs of the patient, such as the heart, are to be imaged. The user can also specify that only a part of an organ or a part of an object such as a region of interest should be imaged. Further, for example, the user can specify that a cardiac computed tomography angiography scan (cardiac CTA scan) should be performed. If the scan type is not given due to the selection made by the user or the like, a predetermined initial scan type is used in the subsequent steps.

  In step 102, a two-dimensional projection image is generated. In order to generate the two-dimensional projection image, the X-ray source 2 does not rotate, and the inspection region 5 including the object is moved in the z direction, that is, the direction parallel to the rotation axis R. That is, the X-ray source 2 and the inspection region 5 move relatively along a linear trajectory. The X-ray source 2 emits X radiation that crosses the object in the examination area 5. X-rays that have passed through the object are detected by the detection unit 6, and the detection unit 6 generates a detection value. These detection values are transmitted to the projection image generation unit 15, and the projection image generation unit 15 generates a projection image of the object from the detection values. This projection image is an overview image. That is, the projection image includes an object, a portion of the object, or a region of interest within the object that must be scanned to allow the scan type defined in step 101 to be performed. The region of the inspection region 5 that is surely large enough is shown. For example, if it is determined in step 101 that the entire patient's heart is to be imaged, i.e., a cardiac scan type is defined, the detected value is used to ensure that the projected image shows at least a human heart. Collected and projected images are generated. For example, in this case, the projected image can show the entire chest. Such a projection image is, for example, a scanogram.

  In step 103, the model providing unit 16 provides a three-dimensional model of the object. The model providing unit 16 is, for example, a memory in which a three-dimensional model of an object corresponding to the scan type defined in step 101 is stored. For example, if a heart scan type is defined by the user in step 101, the model providing unit 16 provides a three-dimensional model having a heart. Preferably, this three-dimensional model not only has the heart itself, but also has registration features that are detectable in the two-dimensional projection image and in the three-dimensional model. These registration shaped objects are, for example, chest bones.

  The three-dimensional model is, for example, an anatomical model of each anatomical region corresponding to the scan type defined in step 101. The anatomical model is, for example, a model of the head / neck region, chest / abdomen region, pelvis, or leg region. These anatomical models have corresponding skeletons and soft tissues, especially organs, located in each anatomical region. For example, the anatomical model of the thoracic region preferably includes the entire spine, thorax, heart, aorta and main arterial branches, lungs, trachea, and diaphragm. One model is disclosed, for example, in Tobias Klinder's dissertation “Geometrical Rib-Cage Modeling, Detection, and Segmentation”, University of Hanover, 2006.

  The order of steps 102 and 103 can be interchanged. That is, step 103 may be performed before step 102.

  In step 104, the provided 3D model and 2D projection image are transmitted to a registration unit 17, which aligns the 3D model with the 2D projection image, and preferably further includes a 3D model. Is adapted to a two-dimensional projection image. For this registration and adaptation, registration features are used in this embodiment. The registration feature is preferably a skeleton that can be identified in the 3D model and in the 2D projection image. Skeletons in the projected image can be detected by threshold distribution, casting search rays (casting), and / or using general Hough transform. The use of search ray casting is disclosed, for example, in C. Lorenz, JvBerg's "Fast automated object detection by recursive casting of search rays", CARS, 2005, and the use of generalized Hough transforms, for example, DH Ballard's “Generalizing the Hough transform to detect arbitrary shapes”, Recognition, 1981, Vol. 13, No. 2, p. 111-122.

  The skeleton is preferably characterized by a gray value pattern across the structure given by the density change between the cortical bone near the surface and the bone marrow in the structure. This change in relation to the typical dimensions of the structure to be searched can be detected by a search beam (search beam casting) that is cast through this volume.

  The registration unit 17 positions the 3D model with respect to the 2D projection image using the registration feature, that is, using the detected skeleton in this embodiment, and converts the 3D model into the 2D projection image. Adapt to. Model positioning and adaptation to the projected image is done by using a 2D-3D registration method. Preferably, the model is positioned and deformed so that the registration features of the model, which in this embodiment is a skeleton, match the registration features of the projected image as closely as possible. This deformation preferably includes translation, rotation, and enlargement or reduction of the three-dimensional model. 2D-3D registration methods are described in, for example, “An approach to 2D / 3D registration of a vertebra in 2D X-ray fluoroscopies with 3D CT images” by J. Weese, TMBuzug, C. Lorenz, C. Fassnacht, VRMed, 1997, p. 119-128, ISBS: 3-540-62794-0, etc., or a radiograph generated from a simulated projection image or model, or S. Lavallee, R. Szeliski's “Recovering the position and orientation of free form objects from image contours using 3D distance maps”, IEEE PAMI, 1995, Vol. 17, No. 4, etc. Use matching to edge shapes in the projected image. For example, an index of similarity such as the sum or correlation of absolute differences can be used, and the 3D model is applied to the registration feature of the 2D projection image and the registration feature of the simulated 2D projection image. Can be modified so that the similarity measure to be minimized. Here, the simulated two-dimensional projection image is obtained by, for example, projecting a modified three-dimensional model in the geometric configuration of the projection of a given two-dimensional projection image, in particular, a modified three-dimensional model. It may be simulated by forward projecting the registration feature. As mentioned above, the registration feature is, for example, a bone, in particular a bone silhouette line and an edge shape.

  For example, if the 3D model is a chest model, preferably the spinal column and ribs are detected as registration features in the 2D projection image. At this time, preferably, the above-described search beam casting technique or general-purpose Hough transform is used. The 2D-3D registration method then preferably positions the 3D chest model so that the ribs and / or spine of the 3D model matches as closely as possible the ribs and / or spine identified in the 2D projection image. And by adapting.

  In this embodiment, the movement determination unit 14 determines the movement of the object, for example the movement of the heart present in the examination region 5. Therefore, the provided 3D model is preferably a moving 3D model of the object, and the registration unit 17 uses the determined movement of the object during the collection of projection images to convert the moving 3D model. It is adapted to match the 2D projection image and preferably to adapt the moving 3D model to the 2D projection image. Thus, for each projection image, or for several projection images, the corresponding motion phase of the object is determined, and during registration and preferably adaptation, the moving 3D model in each motion phase is It is matched and preferably adapted to a two-dimensional projection image having a respective motion phase.

  In step 105, the matched 3D model is transmitted to the scan parameter determination unit 18, and one or more scan parameters are determined from the matched 3D model. Since the dimensions and position of the object are known in the 3D model, one or more scan parameters may be determined by the object, i.e., for example, the entire object, a portion of the object, or the region of interest of the object. Can be determined to be imaged by the imaging system. For example, if the object to be imaged is the heart and the 3D model is a chest model that is already matched to the 2D projection image, the region to be scanned by the rays of the radiation unit 2 is the heart The scan parameters can be determined such that the whole, part of the heart, or region of interest of the heart can be reconstructed. Also, from the matched 3D chest model including the 3D model of the heart, for example, the tomographic position and intratomographic position of the aortic contrast peak measurement used during the delay time of the bolus injection method can be determined.

  Preferably, the three-dimensional model is an anatomical three-dimensional model, such as a chest model consisting of components (eg, individual vertebrae, ribs, organs) that carry a component-specific local coordinate system. The relationship between individual coordinate systems is known, for example, by learning during the generation of an anatomical three-dimensional model. The position, orientation, and dimensions of the registration feature, which is the skeleton in this embodiment, are known after the registration stage 104, and the registration features, i.e., the registration components, and soft tissue organs, etc. Since the spatial relationships between the individual coordinate systems of other components are known, for example, objects in the anatomical 3D model or regions of interest in the anatomical model, such as the position, orientation and dimensions of the heart The position, orientation and dimensions of can be easily determined.

  Since the position, orientation and dimensions of one or more objects or components are known, this information can be used to determine at least one scan parameter depending on the scan type defined in step 101. it can. For example, if a cardiac scan requiring imaging of the entire heart is defined in step 101, the position, orientation, and dimensions of that particular patient's heart are known so that irradiation can be performed to reconstruct the heart image. The area of the patient that must be done can be easily determined. Also, if the cardiac CTA scan type is given in step 101, the position, orientation and dimensions of the aorta can be determined from the matched anatomical model and the contrast used for the bolus injection delay time Scan parameters can be defined so that an image of the aorta can be reconstructed for peak measurement. This bolus is a contrast rapid intravenous infusion used to visualize the blood vessels of the heart.

  The determination of one or more scan parameters is preferably done automatically.

  At step 106, the display 11 displays at least one of the 2D projection image, the matched 3D model, and the determined scan parameters. In step 107, the user may change the registration of the three-dimensional model with the two-dimensional projection image and / or the determined scan parameter by using the changing unit 19. The change unit 19 changes the registration, for example, by changing the position of the three-dimensional model with respect to the two-dimensional projection image, for example, or the examination determined as the scan parameter selectively in step 105, for example. It has a graphical user interface that makes it possible to change the scan parameters determined by changing the region of interest in region 5. If the user changes the registration of the 3D model with the 2D projection image, preferably the scan parameter is determined again at step 105 using the changed registration of the 3D model with the 2D projection image. Is done. In another embodiment, after the registration is changed by the user in step 107, the method uses the changed position of the 3D model relative to the 2D projection image as a 2D projection image for registration. The 3D model is used as the initial position of the 3D model, or the 3D model having a certain fixed position and the orientation changed by the changing unit 19 is adapted to the 2D projection image. Alternatively, only the reduction can be performed and the registration in step 104 can continue.

  In step 108, the inspection area 5, and hence the object, is scanned according to the scan parameters determined in step 105. For example, if a scan parameter that is an area within the examination area 5 to be imaged, i.e., a region of interest, is determined in step 105, the radiation source 2 and the examination area 5 are inspected in step 105. Relative movement is performed so that enough detection values are collected to reconstruct the image of the region within the region. In step 109, an image of the object is reconstructed using the detection values collected in step 108. This reconfiguration is performed by a reconfiguration unit. The reconstruction unit preferably uses a filtered backprojection technique to reconstruct the object. Other reconstruction techniques such as the inverse Radon transform can also be used. In the reconstruction, preferably the movement of the object determined by the movement determination unit 14 is taken into account.

  Steps 106 and / or 107 may be omitted. If step 106 is omitted, the imaging method for imaging the object does not perform visualization of at least one of registration with the two-dimensional projection image of the three-dimensional model and the determined scan parameter. If step 107 is omitted, the imaging method for imaging the object does not allow changing at least one of the registration of the 3D model with the 2D projection image and the determined scan parameters.

  Hereinafter, an embodiment of a scan parameter determination method for determining a scan parameter that can be used by an imaging system that scans an object according to the scan parameter will be described with reference to FIG.

  In step 201, a three-dimensional model of an object to be imaged is provided by the model providing unit 16. The provision of this three-dimensional model corresponds to step 103 in FIG.

  In step 202, the provided 3D model and the 2D projection image of the object provided by the projection image generation unit 15 are matched by the registration unit 17. Furthermore, preferably, the registration unit 17 adapts the three-dimensional model to the two-dimensional projection image. This stage 202 corresponds to stage 104.

  In step 203, the matched 3D model is transmitted to the scan parameter determination unit 18, and one or more scan parameters are determined from the matched 3D model. The determination of one or more scan parameters from this matched 3D model corresponds to step 105 of FIG.

  At step 204, the display 11 displays at least one of the 2D projection image, the matched 3D model, and the determined scan parameters. In step 205, the user may change the registration of the three-dimensional model with the two-dimensional projection image and / or the determined scan parameters by using the changing unit 19. The provision of the change by the change unit 19 corresponds to step 107 in FIG.

  In step 206, the scan parameter determination method for determining the scan parameters ends.

  For a more detailed description of steps 201-205, reference may be made to the corresponding steps 103-107 described above.

  Steps 204 and / or 205 may be omitted. If step 204 is omitted, at least one of the registration of the 3D model and the two-dimensional projection image and the scan parameter is not visualized, and if step 205 is omitted, the scan parameter determination method is It does not allow the user to change at least one of the registration of the 3D model with the 2D projection image and the determined scan parameters.

  Although the imaging system described above has a motion determination unit 14, the present invention is not limited to an imaging system having a motion determination unit. For example, the imaging system may be an imaging system that does not have a motion determination unit.

  The expression “imaging object” and similar expressions includes imaging the entire object, a part of the object, and / or a region of interest of the object. The imaging system may image a plurality of objects.

  The present invention is not limited to an imaging system that is a computed tomography system. For example, the imaging system may be an X-ray system mounted on the C arm.

  The present invention is not limited to imaging systems that image organs or other objects of a patient. For example, a technical object may be imaged. For example, in manufacturing quality control, a technical object must be imaged for monitoring purposes, but the technical object may be different and cannot be placed in the imaging system in the same way. . The imaging system and the scan parameter determination device according to the present invention can accurately and highly reliably reproduce a technical object in manufacturing quality control regardless of the form, position, and orientation of each technical object. Makes it possible to monitor.

  Those skilled in the art in practicing the claimed invention can understand and make other changes to the disclosed embodiments by learning from the drawings, the disclosure and the dependent claims. In the claims, the term “comprising” does not exclude other elements or steps, and the indefinite article “a or an” does not exclude a plurality. In particular, the term “scan parameter” in claim 1 does not limit the invention to the determination of the only scan parameter. A plurality of scan parameters may be determined according to the present invention.

  A single unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.

  The computer program may be stored on or distributed on any suitable medium, such as an optical storage medium or semiconductor medium, provided with or as part of other hardware, for example, It may be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

  Any reference signs in the claims should not be construed as limiting the scope.

Claims (8)

An imaging system for imaging an object adapted to scan an object according to scan parameters:
A projection image generation unit for generating a two-dimensional projection image of the object;
A model providing unit for providing a given anatomical 3D model of the object, the 3D model comprising registration features that are detectable in the 2D projection image and in the 3D model; Including model providing unit ,
A registration unit for aligning the 3D model with the 2D projection image, the registration unit configured to adapt the 3D model to the 2D projection image ;
A scan parameter determination unit for determining the scan parameters from the matched three-dimensional model;
An imaging system.   The change unit according to claim 1, further comprising: a change unit that allows a user to change at least one of registration between the two-dimensional projection image and the three-dimensional model and a determined scan parameter. Imaging system.   The imaging system includes a motion determining unit that determines the motion of the object in three dimensions, and the model providing unit is adapted to provide a moving three-dimensional model of the object, and the registration A unit is adapted to match the moving three-dimensional model with the two-dimensional projection image using the determined movement of the object, and the scan parameter determining unit is adapted to match the moving three-dimensional model The imaging system of claim 1, wherein the imaging system is adapted to determine the scan parameter from a A scan parameter determination device for determining a scan parameter, which can be used by an imaging system that scans an object according to a scan parameter, wherein the scan parameter determination device is generated by a projection image generation unit. Given a two-dimensional projection image of
The scan parameter determination device is:
A model providing unit for providing a given anatomical 3D model of the object, the 3D model comprising registration features that are detectable in the 2D projection image and in the 3D model; Including model providing unit ,
A registration unit for aligning the 3D model with the 2D projection image, the registration unit configured to adapt the 3D model to the 2D projection image ;
A scan parameter determination unit for determining the scan parameters from the matched three-dimensional model;
A scan parameter determination device. An imaging method for imaging an object adapted to scan an object according to scan parameters, comprising:
A projection image generation unit generates a two-dimensional projection image of the object;
The model providing unit provides a given anatomical 3D model of the object, the 3D model being registered in the 2D projection image and in the 3D model detectable in the 3D model; Including parts, stages ,
-A registration unit aligning the 3D model with the 2D projection image, and adapting the 3D model to the 2D projection image ;
A scan parameter determination unit determines the scan parameters from the matched three-dimensional model;
An imaging method comprising: A scan parameter determination method for determining a scan parameter, which can be used by an imaging system that scans an object according to a scan parameter, the scan parameter determination method comprising the object generated by a projection image generation unit Given a two-dimensional projection image of
The scan parameter determination method is:
The model providing unit provides a given anatomical 3D model of the object, the 3D model being registered in the 2D projection image and in the 3D model detectable in the 3D model; Including parts, stages ,
-A registration unit aligning the 3D model with the 2D projection image, and adapting the 3D model to the 2D projection image ;
A scan parameter determination unit determines the scan parameters from the matched three-dimensional model;
A method for determining scan parameters. A computer program for imaging an object, which causes a computer to execute the steps of the imaging method according to claim 5 when executed on a computer that controls the imaging system according to claim 1. A computer program having code. A computer program for determining a scan parameter, wherein when executed on a computer that controls the scan parameter determination device according to claim 4 , the steps of the scan parameter determination method according to claim 6 are executed by the computer. A computer program having program code to be executed.

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