Method and system for providing visual assistance in performing medical intervention on hollow organs

Abstract

In order to provide visual assistance during a medical intervention of a hollow organ (11) of a patient (5), reference data comprising a reference representation (19) of the hollow organ (11) is obtained, an X-ray projection image of the hollow organ (11) is generated, superposition information is determined on the basis of the reference data, and the superposition image is displayed by means of a display device (4), the superimposition image corresponds to the X-ray projection image superimposed with the superimposition information. The reference data contains planning information relating to the condition of the at least one characteristic feature (14, 15a, 15b) of the hollow organ (11) in the reference representation (19). A reference volume (6 ') in the reference representation (19) is determined on the basis of the planning information. A reconstruction (6) of a volume of the patient (5) corresponding to the reference volume (6 ') is generated by means of a tomosynthesis method. Registration data is generated in such a way that the reference volume (6 ') is registered with the reconstruction (6) and superposition information is superimposed on the X-ray projection image as a function of the registration data.

Description

Technical Field

[0001] The invention relates to a method for providing visual assistance during a medical intervention on a hollow organ of a patient, wherein reference data including a reference representation of the hollow organ are acquired, an X-ray projection image of the hollow organ is generated, superimposed information is determined based on the reference data, and the superimposed image is displayed by means of a display device, the superimposed image corresponding to the X-ray projection image superimposed with the superimposed information. The invention also relates to a corresponding system for providing visual assistance during a medical intervention on a hollow organ of a patient and a correspondingly assigned computer program product. Background Art

[0002] Abdominal aortic aneurysm (AAA) refers to an enlargement of the abdominal aorta, which occurs, for example, in the area between the branches of the aorta and the outlet of the blood vessels to the kidneys. AAA may rupture in a life-threatening manner, and a large amount of blood may enter the abdominal cavity.

[0003] For example, an intervention with a catheter can be performed to treat AAA. A vascular graft is introduced via a catheter through an inguinal incision, enlarged and positioned at the site of the aneurysm. During the intervention, the correct positioning of the vascular graft can be monitored, for example, with the aid of fluoroscopy.

[0004] The problem here is that the aorta may be difficult to identify in the X-ray projection image if no contrast agent is used during imaging. Therefore, the preoperative CT image dataset can be registered with a system for fluoroscopy (also known as fluoroscopy or X-ray examination) so that the aorta and / or planning information in the CT image dataset can be displayed on the X-ray projection image during fluoroscopy to provide visual assistance to medical personnel during the implantation process.

[0005] Against this background, DE 10 2011 080 588 A1 describes a method for 3D / 3D registration of a first 3D image data set recorded by a computed tomography scanner and a second 3D image data set recorded by a C-arm system. Body parts are segmented or models are generated from the first 3D image data set. First, the first 3D image data set is roughly registered with the second 3D image data set. Based on this, a fine registration is performed based on the segmented body parts or their models, wherein only the segmented body parts or their models are spatially aligned with the body parts in the second 3D image data set in certain areas.

[0006] A disadvantage here is the high complexity required for generating the second 3D image data set, since for this purpose in particular a very large number of individual 2D images must be recorded from different directions in order to reconstruct the second 3D image data set from this using computed tomography.

[0007] Although this issue is described with respect to visual aids in implanting vascular grafts in AAA, similar situations may arise in other medical interventions, particularly interventions into hollow organs. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide visual assistance to medical personnel at a relatively low cost when performing medical intervention on a patient's hollow organ.

[0009] The technical problem is solved by a method for providing visual assistance during medical interventions on a patient's hollow organ, a system for providing visual assistance during medical interventions on a patient's hollow organ, and a computer program product with instructions. The invention is based on the idea of ​​registering a reference volume of a preoperative reference image with a corresponding reconstructed image obtained by means of tomosynthesis. In this case, the reference volume is determined based on planning information and tomosynthesis is performed accordingly.

[0010] According to one aspect of the invention, a method is provided for providing visual assistance during an intervention on a hollow organ of a patient, in particular by providing visual assistance by fluoroscopy, in particular for providing visual assistance to medical personnel. Reference data are obtained, for example, by at least one computing unit, which reference data contain a preoperative reference illustration of the hollow organ, in particular a three-dimensional reference illustration. For example, during the intervention, an X-ray projection image of the hollow organ is generated, in particular by controlling an X-ray imaging device by at least one computing unit. For example, superimposed information is determined by at least one computing unit based on the reference data. The superimposed image is displayed by means of a display device, for example, which is controlled by at least one computing unit. The superimposed image corresponds to the X-ray projection image superimposed with the superimposed information.

[0011] The reference data further comprises planning information relating to at least one corresponding state of at least one characteristic feature of the hollow organ in the reference representation. A reference volume in the reference representation is determined based on the planning information, in particular based on the corresponding state of the at least one characteristic feature. A reconstruction of a patient volume corresponding to the reference volume is generated by means of a tomosynthesis method, in particular during an interventional procedure, based on the reference volume in the reference representation, in particular by controlling an X-ray imaging device by at least one computing unit. Registration data are generated, in particular by at least one computing unit, in such a way that the reference volume is registered with the reconstruction. In order to generate a superimposed image, the superimposed information is superimposed on the X-ray projection image based on the registration data.

[0012] The reference data can be obtained by at least one computing unit, for example by providing the reference data on a computer-readable storage medium.

[0013] The medical intervention can be, for example, a diagnostic intervention and / or a therapeutic intervention. In particular, it can be an intervention for implanting a vascular graft, also known as a vascular prosthesis or intravascular stent, for example, an intervention for treating an abdominal aortic aneurysm (AAA). In the latter case, the hollow organ is the patient's abdominal aorta. However, the medical intervention itself or other surgical measures, etc., are not part of the method according to the invention.

[0014] The reference representation is in particular a three-dimensional representation of at least the hollow organ determined by an imaging method before a medical intervention, ie preoperatively, or at least a corresponding preoperative three-dimensional model of the hollow organ. The reference representation can be, for example, a three-dimensional computed tomography reconstruction, CT reconstruction.

[0015] The X-ray projection image and the reconstruction of the volume corresponding to the reference volume and the reference representation are not necessarily generated by means of the same X-ray imaging device, even if the reference representation is also generated by using X-ray imaging. The reference representation can be generated, for example, by means of a CT system, while the X-ray imaging device for generating the X-ray projection images and performing the tomosynthesis method can be a C-arm X-ray system, for example a C-arm X-ray angiography system.

[0016] Here and below, the term "position" can be understood to include a corresponding position, in particular a three-dimensional position, and a corresponding orientation, in particular a three-dimensional orientation. The planning information contains information related to the position of at least one characterizing feature. The planning information contains information related to the corresponding position of the characterizing feature for each characterizing feature of at least one characterizing feature. The reference data can also include planning information related to at least one corresponding size and / or shape of at least one characterizing feature in the reference illustration. The reference volume can also be determined based on the size and / or shape of at least one characterizing feature. The planning information can also include, for example, segmentation of a hollow organ.

[0017] The characteristic feature of a hollow organ can be an anatomical feature. If the hollow organ is a blood vessel, the characteristic feature is, for example, a structure at the vascular wall of the hollow organ, a vascular outlet, i.e., a location where a blood vessel on the vascular wall intersects with another blood vessel, or a vascular bifurcation point, etc. The characteristic feature of a hollow organ can also be a geometric feature. If the hollow organ is a blood vessel, the characteristic feature is, for example, a geometric body that surrounds or partially surrounds the hollow organ, a so-called center line, i.e., a line that extends centrally through the blood vessel. If the blood vessel is regarded as a tube with an approximately circular cross section, the center line, for example, always extends through the corresponding center of the circle. The cross-sectional area of ​​the blood vessel can also be a characteristic feature of a hollow organ.

[0018] In the tomosynthesis method, in particular, a sequence of further X-ray projection images is generated, wherein each X-ray projection image of the sequence at least partially represents the hollow organ according to a respectively predefined different projection direction. Based on the X-ray projection images of the sequence, a three-dimensional reconstruction of a volume region of the patient, referred to as the tomosynthesis volume, can then be generated, for example by inverse Radon transformation.

[0019] Thus, tomosynthesis methods have in common with CT methods, wherein, in CT methods, the projection direction always passes through a recording angle range of at least 180°, while in tomosynthesis methods, the recording angle range through which the projection direction passes is less than 180°. This smaller recording angle range results in a smaller thickness of the tomosynthesis volume than in CT methods. The tomosynthesis volume corresponds to a volume bounded by two mutually parallel planes, which volume can also be referred to as a plane slice, wherein the thickness of the plane slice corresponds to the distance between the two parallel planes.

[0020] The larger the recording angle range through which the projection direction passes, the greater the layer thickness. The layer thickness can be, for example, of the order of magnitude of 1 cm to at least 10 cm, for example not more than 20 cm.

[0021] The slice thickness of the tomosynthesis volume is determined by the recording angle range, while the condition of the tomosynthesis volume is given by the position of the isocenter of the X-ray imaging device and a reference recording direction corresponding to the central reference angle of the recording angle range. The parallel planes defining the tomosynthesis volume are in particular perpendicular to the reference recording direction, and the center of the tomosynthesis volume is located at the isocenter of the X-ray imaging device.

[0022] According to the invention, a reference volume is determined from the reference representation using planning information. The reference volume is defined, in particular, like the tomosynthesis volume, as a planar slice. If the conditions and slice thicknesses of the reference volume are known, the tomosynthesis method can be performed, in particular by correspondingly selecting or setting the corresponding acquisition angle ranges, reference acquisition directions and isocenters, in such a way that the resulting tomosynthesis volume is a volume of the patient that corresponds to the reference volume.

[0023] In particular, it is not necessary to precisely register the reference image or reference volume with the X-ray imaging device or the patient in advance. Nevertheless, it may be advantageous to perform a corresponding rough registration or pre-registration in order to reduce the computational effort required to generate the registration data or to increase the reliability of the optimization process that may be involved.

[0024] The reference volume is then registered with the reconstruction using known registration methods, in particular 3D / 3D registration methods, to generate registration data. The registration data therefore specify in particular how the individual voxels of the reconstruction must be transformed, i.e. in particular rotated and / or shifted, in order to transform them to the corresponding voxels of the reference volume, or vice versa. The registration data can therefore be used to correspondingly transform the overlay information, which also comes from the reference data, so that it is adapted to the X-ray projection image. Therefore, superimposing the overlay information on the X-ray projection image according to the registration data can be understood in particular to mean that the overlay information is transformed according to the registration data and the transformed overlay information is superimposed on the X-ray projection image, or that the X-ray projection image is transformed according to the registration data and the overlay information is superimposed on the transformed X-ray projection image.

[0025] The superimposed information can include a two-dimensional representation of a hollow organ or other organ of the patient, which is obtained from the three-dimensional reference representation. Alternatively or additionally, the superimposed information can also contain a two-dimensional representation of characteristic features or other planning information.

[0026] Thus, during interventions in hollow organs, medical personnel can be visually assisted by the method according to the invention by superimposed images, wherein a very precise registration of the superimposed information with the X-ray projection images is achieved without the need for a complete CT reconstruction and / or the use of contrast agents for registration.

[0027] According to at least one embodiment, the reference volume is determined as a planar layer. To determine the reference volume, it is necessary to determine the layer thickness of the planar layer and the position of the planar layer in the reference representation, in other words relative to the reference representation.

[0028] As described above, a volume corresponding to the reference volume can thus be reconstructed by tomosynthesis in a certain range of acquisition angles. The specific determination of the slice conditions and the slice thicknesses depends in particular on the hollow organ and the intervention to be performed.

[0029] In some embodiments wherein the hollow organ is a tube, in particular a blood vessel, the at least one characterizing feature comprises a centerline.

[0030] In some embodiments, the reference volume is defined such that the center of the reference volume is located on the center line. The center of the reference volume is in particular a point that is at the same distance from two parallel planes of the planar slices.

[0031] This ensures that the relevant region of the hollow organ is located as far as possible in the reference volume and is included in the reconstruction.

[0032] According to at least one embodiment, the at least one characterizing feature comprises a first blood vessel outlet site on the blood vessel. In addition, the at least one characterizing feature may further comprise a second blood vessel outlet site on the blood vessel.

[0033] According to at least one embodiment, the reference volume is determined in such a way that it at least partially encompasses the first vessel outlet site or the second vessel outlet site, preferably at least partially the first vessel outlet site and the second vessel outlet site, respectively.

[0034] This ensures that the relevant region of the hollow organ is located as far as possible in the reference volume and is included in the reconstruction.

[0035] In particular if the hollow organ is the abdominal aorta and the intervention involves implanting a vascular graft in the abdominal aorta, the reference volume can be determined, for example, such that the reference volume at least partially contains the first and second vessel exit sites, respectively, and the center of the reference volume lies on the center line.

[0036] According to at least one embodiment, a parameter set for performing the tomosynthesis method is determined based on the reference volume, in particular based on the conditions of the plane slices and the slice thicknesses. The tomosynthesis method is then performed based on the parameter set.

[0037] According to at least one embodiment, the parameter set comprises an acquisition angle range and the acquisition angle range is determined as a function of the slice thickness, in particular using a known relationship between the acquisition angle range and the tomosynthesis slice thickness.

[0038] This makes it possible for the slice thickness of the reconstructed volume to be made consistent with the slice thickness of the reference volume.

[0039] According to at least one embodiment, the parameter set comprises a reference recording direction corresponding to a predefined reference angle of the recording angle range, and the reference recording direction is determined depending on the conditions, in particular the orientation, of a plane layer of the reference volume, in particular relative to the reference representation.

[0040] This makes it possible for the orientation of the reconstructed volume relative to the patient or the hollow organ to correspond to the orientation of the reference volume relative to the reference representation of the hollow organ.

[0041] According to at least one embodiment, the parameter set comprises an isocenter position, in particular an isocenter position of an X-ray imaging device or a tomosynthesis method, and the isocenter position is determined depending on the conditions, in particular the position, of a plane layer of a reference representation, in particular relative to the reference representation.

[0042] This makes it possible for the position of the reconstructed volume relative to the patient or the hollow organ to correspond to the position of the reference volume relative to the reference representation of the hollow organ.

[0043] According to at least one embodiment, a sequence of further X-ray projection images is generated to perform the tomography method, wherein each X-ray projection image of the sequence at least partially represents the hollow organ according to a respectively differently predefined projection direction. The projection directions of the X-ray projection images of the sequence are characterized by respective angles within a range of recording angles in a plane, wherein the reference recording direction lies in the plane. The reconstruction is generated based on the X-ray projection images of the sequence.

[0044] The reconstruction is based on the other X-ray projection images of the sequence using a known reconstruction algorithm for tomosynthesis, for example based on inverse Radon transformation. The total number of other X-ray projection images of the sequence can be in the order of 10 to several dozen, for example in the range of [10,50].

[0045] The tomosynthesis method is performed in particular without the use of contrast agents. Therefore, the sequence of further X-ray projection images is produced without contrast agents or without significant amounts of contrast agents in the hollow organ.

[0046] This allows a 3D / 3D registration of the reconstruction with the reference volume and thus a high degree of precision in the superposition of the superposition information, while nevertheless requiring significantly less effort for the registration than alternative methods such as intraoperative CT reconstruction.

[0047] The sequence corresponds in particular to a temporal sequence or a temporally ordered sequence of further X-ray projection images, wherein the total number of further X-ray projection images of the sequence is predefined. Each further X-ray projection image of the sequence at least partially represents at least one hollow organ according to a respectively differently predefined projection direction, which can be understood in particular in that the respective individual projection directions are predefined for all other X-ray projection images in the sequence and are respectively different from one another for all other X-ray projection images of the sequence. Thus, the projection directions of two different further X-ray projection images of the sequence are always different from one another.

[0048] The reference angle can be, for example, zero, so that the shooting angle range is in particular [-α / 2, α / 2], α<180°. The shooting angle range can also be defined as [0, α], α<180°, where the reference angle is α / 2. Angle α can also be understood as the maximum angle difference in the shooting angle range.

[0049] According to at least one embodiment, the maximum angular difference of the recording angle ranges is less than 180°, in particular less than or equal to 90°, for example less than or equal to 60°, for example less than or equal to 45°.

[0050] This results in, among other things, a significantly lower outlay compared to methods such as intraoperative CT reconstruction.

[0051] According to at least one embodiment, a preregistration of the reference representation with the patient is performed before the tomosynthesis method is carried out, in particular during an intervention.

[0052] The reliability of the registration of the reference volume with the reconstruction can thereby be improved.Algorithms known per se can be used for the pre-registration.

[0053] According to at least one embodiment, a first reference X-ray projection image of the hollow organ is generated to perform a pre-registration, and the reference representation is registered with the first reference X-ray projection image.

[0054] This makes preregistration particularly easy to implement.

[0055] According to at least one embodiment, a second reference X-ray projection image of the hollow organ is generated for pre-registration, wherein the projection direction used to generate the first reference X-ray projection image and the projection direction used to generate the second reference X-ray projection image are different from each other. The reference illustration is registered with the first additional X-ray projection image and the second reference X-ray projection image.

[0056] This makes it possible to improve the accuracy of the pre-registration and thus increase the reliability of the registration of the reference volume with the reconstruction.

[0057] According to another aspect of the invention, a system for providing visual assistance during a medical intervention on a hollow organ of a patient is provided. The system has an X-ray imaging device, which is configured to generate an X-ray projection image of the hollow organ, in particular controlled by at least one computing unit of the system. The at least one computing unit is configured to obtain reference data containing a reference representation of the hollow organ, determine superposition information based on the reference data, and generate a superposition image corresponding to the X-ray projection image superimposed with the superposition information.

[0058] The reference data comprises planning information relating to the condition of at least one characteristic feature of the hollow organ in the reference representation. The at least one computing unit is configured to determine a reference volume in the reference representation based on the planning information. The at least one computing unit is configured to control the X-ray imaging device to perform a tomosynthesis method and to generate a reconstruction of a volume of the patient corresponding to the reference volume based on a result or an intermediate result of the tomosynthesis method. The at least one computing unit is configured to generate registration data and to register the reference volume with the reconstruction for this purpose and to superimpose the superposition information on the X-ray projection images based on the registration data.

[0059] The result or intermediate results of the tomosynthesis method can be output, for example, as described above, via a sequence of further X-ray projection images.

[0060] The X-ray imaging device has, in particular, an X-ray source, an X-ray detector and a drive device for positioning the X-ray source and the X-ray detector relative to the hollow organ in accordance with different projection directions.

[0061] The at least one computing unit is configured in particular to control the drive and the x-ray source in order to generate x-ray projection images and to perform a tomosynthesis method. The at least one computing unit is configured to acquire corresponding detector signals from the x-ray detector and to generate x-ray projection images or a sequence of further x-ray projection images as a function of these detector signals.

[0062] A computing unit can be understood in particular as a data processing device containing a processing circuit. A computing unit can in particular process data for performing computing operations. The computing operations may also include operations for performing search accesses to data structures, such as a lookup table LUT (English: "look-up table").

[0063] The computing unit may include, in particular, one or more computers, one or more microcontrollers and / or one or more integrated circuits, for example, one or more application-specific integrated circuits ASIC (English: “application-specific integrated circuit”) and / or one or more field-programmable gate arrays FPGA and / or one or more single-chip systems SOC (English: “system on a chip”). The computing unit may also include one or more processors, for example, one or more microprocessors, one or more central processing units CPU (English: “central processing unit”), one or more graphics processing units GPU (English: “graphics processing unit”) and / or one or more signal processors, in particular one or more digital signal processors DSP. The computing unit may also include a physical or virtual complex of a computer or other of the units mentioned.

[0064] In various embodiments, a computing unit includes one or more hardware and / or software interfaces and / or one or more storage units.

[0065] The memory cell can be designed as a volatile data memory, for example a dynamic random access memory DRAM (English: dynamic random access memory) or a static random access memory SRAM (English: static random access memory), or as a non-volatile data memory, for example a read-only memory ROM (English: read-only memory), a programmable read-only memory PROM (English: programmable read-only memory), an erasable programmable read-only memory EPROM (English: erasable programmable read-only memory), an electrically erasable programmable read-only memory EEPROM (English: electrically erasable programmable read-only memory), a flash memory or a flash EEPROM, a ferroelectric random access memory FRAM (English: ferroelectric random access memory), a magnetoresistive random access memory MRAM (English: magnetoresistive random access memory) or a phase change random access memory PCRAM (English: phase-change random access memory).

[0066] The X-ray source and the X-ray detector are always positioned and / or oriented identically, regardless of the respective projection direction. The X-ray source and the X-ray detector can be rigidly connected to one another, for example, by a C-arm or the like. The drive device comprises, for example, one or more motors or transmissions for moving, in particular simultaneously moving, the X-ray source and the X-ray detector in order to set the individual projection directions.

[0067] The X-ray imaging device can be designed in particular as a C-arm X-ray angiography system.

[0068] According to at least one embodiment, the system comprises a display device, and the at least one computing unit is configured to control the display device to display the superimposed image.

[0069] Further embodiments of the system according to the invention are derived directly from different embodiments of the method according to the invention and vice versa. The individual features and the corresponding explanations and advantages associated with the various embodiments of the method according to the invention can in particular be transferred analogously to the corresponding embodiments of the system according to the invention. The system according to the invention is in particular designed or programmed to implement the method according to the invention. The system according to the invention in particular implements the method according to the invention.

[0070] According to another aspect of the invention, a computer program is provided which has instructions which, when executed by a system according to the invention, in particular by at least one computing unit of the system, cause the system to perform a method according to the invention.

[0071] The instructions may be present as program code, for example. The program code may be provided in the form of binary code or assembler and / or programming language, such as source code of C language and / or program script, such as Python, for example.

[0072] According to another aspect of the present invention, there is provided a computer-readable storage medium storing a computer program according to the present invention.

[0073] According to the invention, a computer program and a computer-readable storage medium may be understood to be a computer program product having instructions.

[0074] Further features of the invention emerge from the drawings and the description of the drawings.

[0075] The features and feature combinations mentioned above in the specification and the features and feature combinations mentioned below in the description of the drawings and / or shown in the drawings may be included by the present invention not only in the respectively given combinations, but also in other different combinations. In particular, embodiments and feature combinations that do not have all the features of the originally stated claims may also be included by the present invention. In addition, embodiments and feature combinations that exceed or deviate from the feature combinations set forth in the reference relationship of the claims may also be included by the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The present invention will be explained in more detail below with the aid of specific embodiments and the associated schematic diagrams. In the accompanying drawings, identical or functionally identical elements may be provided with identical reference numerals. It is not necessary to repeat the description of identical or functionally identical elements with respect to different figures when necessary.

[0077] In the attached picture:

[0078] Figure 1 A schematic diagram showing an exemplary embodiment of a system according to the present invention for providing visual assistance during intervention on a hollow organ of a patient;

[0079] Figure 2 A schematic flow chart showing an exemplary embodiment of a method according to the invention for providing visual assistance during an intervention on a hollow organ of a patient;

[0080] Figure 3 A schematic diagram of the abdominal aorta and abdominal aortic vascular graft is shown;

[0081] Figure 4schematically shows a preoperative reference representation of a hollow organ and a reference volume according to another exemplary embodiment of the method according to the invention; and

[0082] Figure 5 A visualization of a step in a tomosynthesis method according to a further exemplary embodiment of the method according to the invention is shown. DETAILED DESCRIPTION

[0083] Figure 1 An exemplary embodiment of a system 1 according to the invention is schematically shown for use in a hollow organ 11 of a patient 5 (see Figure 3 ) provides visual assistance when performing medical intervention. System 1 has an imaging device 2.

[0084] The imaging device 2 can be designed as a C-arm X-ray angiography system, for example. The imaging device 2 has, in particular, an X-ray source 8 and an X-ray detector and a drive device for positioning the X-ray source 8 and the X-ray detector 9 relative to a recording region, so as to position the patient 5 or the hollow organ 11 according to different projection directions. The recording region can correspond, for example, to a region on a patient couch, which can be recorded by means of the X-ray source 8 and the X-ray detector 9.

[0085] The projection direction can be determined, for example, by a connection between the X-ray source 8 and the X-ray detector 9 and a reference direction, for example Figure 1 The X-ray source 8 and the X-ray detector 9 can be driven by a drive device such as Figure 1 The rotation direction 10 is shown in FIG. 1 and the rotation direction 10 is shown in FIG. Figure 1 In particular, the rotation axis is perpendicular to the plane of the drawing.

[0086] In addition, the system 1 has at least one computing unit 3, which can control the X-ray source 8 to emit X-rays on the one hand, and on the other hand enable the X-ray detector 9 to receive corresponding detector signals or detector data, which correspond to the projection image corresponding to the current projection direction. The at least one computing unit 3 can also control the drive device to set different projection directions. The system 1 can, for example, have a display device 4, which can also be controlled by the at least one computing unit 3.

[0087] The method according to the invention can be carried out with the aid of the system 1 . Figure 2 A schematic flow chart showing an exemplary embodiment of such a method is shown.

[0088] In step 200, at least one computing unit 3 can receive reference data comprising a reference representation 19 of the hollow organ 11 (see Figure 4The reference data also include at least one feature 14, 15a, 15b of the hollow organ 11 (see Figure 3 In step 210, at least one computing unit 3 determines a reference volume 6' (see FIG. 19 ) in reference diagram 19 based on the planning information. Figure 4 ).

[0089] In step 220, for example, a preregistration of the reference image 19 with the patient 5 can be performed. Starting from the preregistration, in step 230, at least one computing unit 3 controls the X-ray imaging device 2 to perform a tomosynthesis method and to generate a reconstruction 6 of a volume of the patient 5 corresponding to the reference volume 6′ based on the result of the tomosynthesis method (see Figure 5 ). In step 240 , the at least one computing unit 3 generates registration data. For this purpose, the at least one computing unit 3 registers the reference volume 6 ′ with the reconstruction 6 .

[0090] In step 250, the X-ray imaging device 2 generates an X-ray projection image of the hollow organ 11 under the control of at least one computing unit 3, and the at least one computing unit 3 determines the superposition information based on the reference data. The at least one computing unit 3 generates a superposition image, which corresponds to the X-ray projection image superimposed with the superposition information according to the registration data. The at least one computing unit 3 can, for example, control the display device 4 so that the display device displays the superposition image.

[0091] like Figure 3 Schematically shown, hollow organ 11 can be, for example, the abdominal aorta of patient 5. The medical intervention can be used, for example, to implant a vascular graft 13 in the region of an abdominal aortic aneurysm 12 between the bifurcation of the abdominal aorta into the two iliac arteries 17a, 17b and the vascular outlets 15a, 15b of the renal arteries 16a, 16b. Figure 4 A corresponding reference representation 19 is shown, for example a segmentation of the abdominal aorta based on CT reconstruction. Characteristic features in this case can be given, for example, by the center line 14 and the two vessel outlets 15a and 15b of the abdominal aorta.

[0092] The reference volume 6' is determined in particular as a plane layer with a determined layer thickness. The plane layer is determined in particular such that it includes or covers the cross section of the vessel outlets 15a, 15b and the abdominal aorta. The reference volume 6' can be determined in particular such that the center 7' of the reference volume 6' is located on a line 14 extending centrally through the vessel 11.

[0093] Accordingly, a parameter set for performing a tomosynthesis method can be determined based on the determination of the reference volume 6'. The parameter set contains a shooting angle range, which is determined according to the layer thickness of the plane layer of the reference volume 6'. In addition, the parameter set also includes, for example, a reference shooting direction 18, which is also referred to as a tomosynthesis vector and determines the center point of rotation in the tomosynthesis method corresponding to a preset reference angle of the shooting angle range, which is determined according to the orientation of the plane layer of the reference volume 6' relative to the reference illustration 19. The parameter set can also include an isocenter position 7, which is determined according to the position of the plane layer of the reference volume 6' relative to the reference illustration 19 and is set, for example, by positioning the patient 5 relative to the X-ray source 8 and the X-ray detector 9. Pre-registration enables the blood vessel outlets 15a, 15b to be roughly oriented in advance. The tomosynthesis is then performed corresponding to the parameter set, and based on this, as shown in FIG. Figure 5 As shown, a reconstruction 6 of a volume corresponding to a reference volume 6 ′ is produced.

[0094] As described above, in particular with reference to the accompanying drawings, the present invention makes it possible to visually assist medical personnel with reduced effort when performing interventions on a patient's hollow organs.

[0095] In various embodiments, this is achieved in particular by registering a reference volume from a preoperative 3D reference representation with the tomosynthesis volume. In particular, neither the use of contrast agents nor a full 3D run in the sense of a CT method is required for the registration. This is achieved in particular by taking into account planning information for defining the reference volume, which in turn provides the parameters required for tomosynthesis.

[0096] Regardless of the grammatical gender of a particular term, persons with either male or female gender identities are included.

Claims

1. A method for providing visual assistance during medical intervention on a hollow organ (11) of a patient (5), in, The medical intervention is not part of the method, The invention relates to a method for performing an X-ray imaging of a hollow organ (11), wherein reference data of a preoperative reference representation (19) of the hollow organ (11) are obtained, an X-ray projection image of the hollow organ (11) is generated, superimposed information is determined based on the reference data, and the superimposed image is displayed by means of a display device (4), the superimposed image corresponding to the X-ray projection image superimposed with the superimposed information, It is characterized in that - the reference data contain planning information relating to the position of at least one characteristic feature (14, 15a, 15b) of the hollow organ (11) in the reference representation (19); - determining a reference volume (6') in the reference diagram (19) based on the planning information; - generating a reconstruction (6) of a volume of the patient (5) corresponding to the reference volume (6') by means of a tomosynthesis method; - generating registration data by registering a reference volume (6') with said reconstruction (6); and - Superimposing the superimposition information onto the X-ray projection image based on the registration data.

2. The method according to claim 1, wherein: The reference volume (6') is determined as the planar layer (6'), and in order to determine the reference volume (6'), the layer thickness of the planar layer (6') and the condition of the planar layer (6') in the reference illustration (19) are determined.

3. The method according to any one of the preceding claims, wherein: A parameter set for performing a tomosynthesis method is determined based on the reference volume (6'), and the tomosynthesis method is performed according to the parameter set.

4. The method according to claims 2 and 3, wherein: - the parameter set comprises a shooting angle range, and the shooting angle range is determined according to the layer thickness; and / or - the parameter set includes a reference shooting direction (18) corresponding to a preset reference angle of the shooting angle range, and the reference shooting direction (18) is determined according to the condition of the plane layer (6'); and / or The parameter set includes an isocenter position (7), and the isocenter position (7) is determined according to the conditions of a planar layer (6').

5. The method according to claim 4, wherein: In order to perform the tomosynthesis method - generating a sequence of further X-ray projection images, wherein each X-ray projection image of the sequence at least partially represents the hollow organ (11) according to a respectively differently predefined projection direction; - the projection direction of the X-ray projection images of the sequence is characterized by a corresponding angle within a range of recording angles in a plane, wherein a reference recording direction (18) is located in the plane; and - Producing a reconstruction based on a sequence of other X-ray projection images (6).

6. The method according to claim 4 or 5, wherein: The maximum angle difference according to the recording angle range is less than 180° or a maximum of 90° or a maximum of 60° or a maximum of 45°.

7. A method according to any one of the preceding claims, wherein: The hollow organ (11) comprises a blood vessel (11), and the at least one characterizing feature (14, 15a, 15b) comprises a line (14) extending centrally through the blood vessel (11).

8. The method according to claim 7, wherein: The reference volume (6') is determined such that the center (7') of the reference volume (6') lies on a line (14) extending centrally through the blood vessel (11).

9. The method according to any one of the preceding claims, wherein: The hollow organ (11) includes a blood vessel (11), and the at least one characteristic feature (14, 15a, 15b) includes a first blood vessel outlet site (15a) on the blood vessel (11).

10. The method according to claim 9, wherein: At least one characterizing feature (14, 15a, 15b) includes a second vessel outlet site (15b) on the blood vessel (11), and a reference volume (6') is determined such that the reference volume at least partially includes the first vessel outlet site (15a) and the second vessel outlet site (15b), respectively.

11. The method according to any one of the preceding claims, wherein: Before the tomosynthesis method is performed, a pre-registration of the reference image (19) with the patient (5) is performed.

12. The method according to claim 11, wherein: For pre-registration, - generating a first reference X-ray projection image of the hollow organ (11); and - Registering the reference representation (19) with the first reference X-ray projection image.

13. The method according to claim 12, wherein: For pre-registration, - generating a second reference X-ray projection image of the hollow organ (11), wherein a projection direction used to generate the first reference X-ray projection image and a projection direction used to generate the second reference X-ray projection image are different from each other; - Registering the reference representation (19) with the second reference X-ray projection image.

14. A system (1) for providing visual assistance during a medical intervention on a hollow organ (11) of a patient (5), the system (1) comprising an X-ray imaging device (2) configured to generate an X-ray projection image of the hollow organ (11), and at least one computing unit (3) configured to obtain reference data containing a reference representation (19) of the hollow organ (11), determine superposition information based on the reference data, and generate a superposition image, the superposition image corresponding to the X-ray projection image superimposed with the superposition information, It is characterized in that - the reference data contain planning information relating to the position of at least one characteristic feature (14, 15a, 15b) of the hollow organ (11) in the reference representation (19); at least one computing unit (3) is configured to determine a reference volume (6') in the reference representation (19) based on the planning information; at least one computing unit (3) is configured to control the X-ray imaging device (2) to perform a tomosynthesis method and to generate a reconstruction (6) of a volume of the patient (5) corresponding to the reference volume (6') based on the result of the tomosynthesis method; At least one computing unit (3) is configured to generate registration data and, for this purpose, to register the reference volume (6') with the reconstruction (6) and to superimpose the superposition information onto the X-ray projection image as a function of the registration data.

15. A computer program product having instructions which, when executed by a system (1) according to claim 14, cause the system to carry out the method according to one of claims 1 to 13.

Images