Spatiotemporal fusion of time-resolved angiography datasets

Abstract

Angiographic recordings should be more convincing. To this end, a method for the spatiotemporal fusion of time-resolved angiographic data sets is proposed. From the three-dimensional data sets of angiography recorded at different locations with contrast agent, respective 4D reconstructions (1, 2) are obtained. A common vascular region (11) is determined in the two 4D reconstructions (1, 2). For each contrast agent bolus, a corresponding time point or time curve (23) is determined in the common vascular region (11). Finally, the two 4D reconstructions (1, 2) are synchronized and fused.

Description

Technical Field

[0001] The invention relates to a method for the spatiotemporal fusion of time-resolved angiographic data sets. The invention also relates to a corresponding image processing device and an angiographic device. The invention also relates to a computer program and an electronically readable data carrier. Background Art

[0002] A so-called AVM (arteriovenous malformation) is usually a mass of blood vessels in the patient's brain and can be supplied by several large arteries. An AVF (arteriovenous fistula) should be understood as a "short circuit" between an artery and a vein and is often difficult to locate and find. In addition, due to so-called shunts or shunts, the venous outflow can occur in a combined manner, which means that there is not just one outflow, but several outflows.

[0003] In order to better understand the flow conditions in AVMs with two inflows, the inflows and their influence on the entire vascular system are currently being investigated separately. For example, two separate 3D-DSA images or 4D-DSA images (DSA: Digital Subtraction Angiography) or similar images are acquired. For the first image, contrast agent is added to the first inflow and for the second image, contrast agent is added to the second inflow. The two images are then spatially fused.

[0004] Such a fusion of 3D or 4D-DSA images is shown in the article by K.-K. Chen, “Application of time-resolved 3D digital subtraction angiography to plan cerebral arteriovenous malformation radio surgery”, 26. January 2017, 10.3174 / ajnr.A5074.” Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to improve the display of complex vascular systems.

[0006] According to the invention, this problem is solved by a method for spatiotemporal fusion of time-resolved angiographic data sets, an image processing device and an angiographic device. In addition, a corresponding computer program and a data carrier are provided. Advantageous improvements of the invention are also provided by the invention.

[0007] In order to assess the entire pathology of, for example, an AVM, an image containing all relevant 4D flow information in a combined form (moving 3D images or 3D videos) would help to understand the AVM architecture and thus facilitate treatment planning. For example, 4D flow data can be acquired using X-ray based medical imaging modalities such as X-ray angiography systems or CT scanners. MRI (magnetic resonance imaging) also allows recording of such 4D images. Furthermore, during treatment, a combined visualization of all relevant structures of all 3D and / or 4D images is helpful.

[0008] According to the invention, a method for spatiotemporal fusion of time-resolved angiographic data sets is provided. Thus, two or more time-resolved angiographic data sets are formed, which are fused not only spatially but also temporally.

[0009] First, a first time-resolved 3D angiographic data set of a patient receiving a first contrast agent at a first position is provided. The provision can be achieved by providing it in a storage unit of a computer, via a cloud or the Internet or via other data carriers. Alternatively, the provision can also be done directly by an angiographic unit, which acquires or obtains the patient's respective time-resolved 3D angiographic data set. This initial data set should represent a record of the patient after receiving the contrast agent at the initial position, such as the first inflow of an AVM. Then, the contrast agent is distributed in the AVM or vascular mass starting from the first inflow.

[0010] Likewise, a second time-resolved angiographic 3D data set of the patient is provided in which a second contrast agent is administered at a second location different from the first location. As with providing the first data set, providing the second data set may also be performed in the various ways described above. Administration of the second contrast agent occurs at a second location different from the first location, such as a second inflow to the AVM. This makes it possible to analyze the effects of the two inflows.

[0011] A first 4D reconstruction is then obtained from the first time-resolved three-dimensional angiographic data set. A 4D reconstruction of three spatial dimensions and one temporal dimension is obtained from the three-dimensional images (three spatial dimensions) taken successively. For example, such a 4D reconstruction is a spatial video recording showing the diffusion of a contrast agent in the examined vascular system. Similarly, a second 4D reconstruction is obtained from the second time-resolved 3D angiographic data set. This provides, for example, two video recordings of the entry of two different contrast agents into the vascular system.

[0012] In a further step, a common vascular region represented by the two 4D reconstructions is determined, wherein the vascular region is from the patient or is part of its vascular system. Thus, this common vascular region is determined in the 4D reconstructions and is therefore displayed in both images. For example, if the AVM has two inflows and contrast agent is administered in two different inflows, the common vascular region represents a vascular region that is commonly supplied by both inflows.

[0013] Then, a first time point or a first time curve (or time course) related to the appearance of a first contrast agent bolus of a first contrast agent in a common vascular region is determined from the first 4D reconstruction. The amount of contrast agent injected during the administration of the first contrast agent, i.e. the contrast agent bolus (bolus for short), is transported from a first location to the common vascular region. This transport takes place at a certain speed, wherein the blood flowing in the blood vessels dilutes the contrast agent. Therefore, the contrast agent administered together with the injection appears in the downstream vascular region with a certain time curve (time-contrast curve). The contrast agent concentration gradually increases after the injection and decreases again later in the tomographic imaging. This change in the contrast agent concentration over time at a vascular point or a vascular region is called the appearance of the contrast agent bolus in the (common) vascular region. With respect to this "appearance", a time point or an entire time curve of the contrast agent concentration can be determined. For example, the determined time can be the time when the bolus arrives at the common vascular region.

[0014] Similarly, a second time point or a second time curve associated with the appearance of a second contrast agent bolus of a second contrast agent administration in the common vessel region is determined from the second 4D reconstruction. For example, the time of arrival of the second bolus in the common vessel region can be determined here.

[0015] After this, the first 4D reconstruction and the second 4D reconstruction can be synchronized according to the first and second time points or time curves. For example, if the first and second time points are the time points at which the respective boluses arrive at a common vessel region, the two arrival time points can be used to synchronize the 4D reconstruction or video. Thus, for example, after synchronization, the two contrast agent boluses arrive at the common vessel region at the same time.

[0016] Finally, the two synchronized 4D reconstructions are fused. Fusion means that the 4D reconstructions are correctly superimposed spatially. Since the 4D reconstructions are also synchronized with each other, fusion is equivalent to 4D fusion. This means that in the fused 4D reconstruction or fused video, not only spatial fusion occurs, but also temporal fusion of the individual reconstructions or videos. Therefore, in other words, a method is proposed to fuse two (or more) angiographic 4D datasets in space and time to produce a single temporally synchronized combined 4D dataset.

[0017] For example, due to the underlying hemodynamics, 4D angiographic images can be temporally registered by identifying the vascular sites (i.e. individual voxels or sites of voxels) that are contrast-enhanced in both (all) 4D datasets. The time points at which these common regions are contrast-enhanced are respectively identified in both (all) 4D images, achieving temporal synchronization of the datasets.

[0018] In one embodiment of the method according to the invention, it is provided that the first and second time points correspond to the arrival time points of each contrast agent bolus in the common vascular region. The vascular region can be selected to be larger or smaller. For example, the vascular region can include a group of blood vessels or a single blood vessel. The respective arrival locations are monitored by image processing. For example, when the contrast agent arrives at the vascular region, a blackening can be detected in the vascular region. For example, with regard to the blackening, a single blood vessel can be monitored, or an average value can be formed in a larger vascular region. As described above, the concentration of the contrast agent in the vascular region initially increases continuously and reaches a maximum value. When the contrast agent flows out, the concentration decreases continuously again. For example, if the concentration or blackening exceeds the detection threshold, this can be defined as the arrival time of the contrast agent bolus. In this way, the arrival time can be determined separately for the first contrast agent bolus and the second contrast agent bolus. The first time point and the second time point thus obtained can then be equated for synchronization.

[0019] In an alternative embodiment of the method according to the invention, it is provided that the first and second time points correspond to the time points of the maximum concentration of the respective contrast agent bolus in the common vessel region. Since the contrast agent concentration has a specific time curve, a defined time point representative of the process can be selected from this time curve. In this case, the concentration maximum is used to determine a representative time of the concentration course. Such a maximum value can be reliably determined by image processing.

[0020] In a further alternative of the method according to the invention, it is provided that the first and second time points correspond to the residence time points of the respective centers of gravity of the respective contrast agent boluses in the common vascular region. For example, the centers of gravity of the respective contrast agent boluses can be determined from the time curve of a relatively short contrast agent bolus. For example, the centers of gravity of the respective contrast agent boluses can be defined as the centers of gravity of the respective curve functions of the contrast agent bolus in the specific vascular region. Such centers of gravity can also be determined automatically by a functional analysis of the contrast agent.

[0021] In a further embodiment, the time point at which the cross-correlation of the first and second time curves (in each case with respect to the contrast agent inflow and outflow or only the inflow) has a maximum is used for the synchronization. Thus, instead of directly determining a time point from each individual time curve, the time curves of the two contrast agents are directly influenced by the cross-correlation or the like. The entire time curve of each contrast agent bolus is therefore used for the synchronization. Figuratively speaking, the two time series are superimposed in such a way that they have the greatest possible correspondence. Thus, for each bolus, not only a single time point is used for the synchronization, but the entire time curve is used.

[0022] According to another embodiment, a plurality of vascular sites into which both the first and second contrast agent boluses flow are determined from the 4D reconstruction, and the vascular site into which the respective contrast agent boluses of the two contrast agent administrations first arrive is automatically determined as a common vascular region. The contrast agent of the first contrast agent and the second contrast agent often flows into several common vascular sites. Since the contrast agent becomes increasingly diluted over time, it is advantageous to select the earliest possible time for synchronization. It is therefore advantageous to use a first common vascular site for synchronization, into which the contrast agent of the first contrast agent administration and the second contrast agent administration both flows. In this first common vascular site, the contrast agent can be best identified, in particular resolved, in each case.

[0023] In a further embodiment, it is provided that at least one further 4D reconstruction is synchronized and fused with the first and second 4D reconstruction. For example, not only two video recordings are synchronized and fused, but three or more video recordings are synchronized and fused. The relevant data sets can be acquired by different imaging modalities (angiography systems, CT scanners, etc.). This allows a better analysis of a very complex vascular system.

[0024] Furthermore, in one embodiment it can be provided that the first and second 4D reconstructions are fused with the 3D angiographic data set. In this way, for example, two video recordings from a smaller vessel region can be projected or embedded into the static overall vessel structure. Thus, for example, the attending physician can plan the treatment better if he sees the region to be treated in the context of a larger vessel tree or the entire vessel tree.

[0025] Furthermore, in one embodiment it can be provided that the first and second 4D reconstructions are fused with the 3D tomographic data set. For example, the 3D tomographic data set reflects the patient's anatomy in detail. Thus, the vascular regions shown by the two 4D reconstructions can be precisely inserted into the spatial anatomy of the patient. This type of fused imaging also helps the planning or treating physician to better assess the vascular situation.

[0026] According to the present invention, the above-mentioned problem is also solved by an image processing device for spatiotemporal fusion of time-resolved angiographic data sets, the image processing device having a storage unit, which is designed to provide a first time-resolved 3D angiographic data set of a patient, the patient receiving a first contrast agent administration at a first position, and to provide a second time-resolved 3D angiographic data set of a patient, the patient receiving a second contrast agent administration at a second position different from the first position, and an image processing unit, which is designed to obtain a first 4D reconstruction from the first time-resolved 3D angiographic data set and a second 4D reconstruction from the second time-resolved 3D angiographic data set, determine a common vascular area of ​​the patient represented by the two 4D reconstructions, determine from the first 4D reconstruction a first time point or a time curve associated with the appearance of a first contrast agent bolus of the first contrast agent administration in the common vascular area, determine from the second 4D reconstruction a second time point or a time curve associated with the appearance of a second contrast agent bolus of the second contrast agent administration in the common vascular area, synchronize the first 4D reconstruction and the second 4D reconstruction according to the first and second time points or time curves, and fuse the two synchronized 4D reconstructions.

[0027] Thus, the image processing device is able to synchronize and fuse 4D angiographic reconstructions according to the above method. The advantages and improvements described above in connection with the method of the invention also apply mutatis mutandis to the image processing device. The individual method steps can be considered as functional features of the corresponding units of the image processing device.

[0028] Furthermore, according to the present invention, an angiography apparatus for spatiotemporal fusion of time-resolved angiography data sets is provided, comprising an angiography unit designed to detect a first time-resolved 3D angiography data set in a patient who has received a first contrast agent at a first position, and to detect a second time-resolved 3D angiography data set in a patient who has received a second contrast agent at a second position different from the first position, and an image processing unit designed to obtain a first 4D reconstruction from the first time-resolved 3D angiography data set and a second 4D reconstruction from the second time-resolved 3D angiography data set, determine a common vascular region of the patient represented by the two 4D reconstructions, determine from the first 4D reconstruction a first time point or a time curve associated with the appearance of a first contrast agent bolus of a first contrast agent administration in the common vascular region, determine from the second 4D reconstruction a second time point or a time curve associated with the appearance of a second contrast agent bolus of a second contrast agent administration in the common vascular region, synchronize the first 4D reconstruction and the second 4D reconstruction based on the first and second time points or time curves, and fuse the two synchronized 4D reconstructions.

[0029] The angiography device here can generate a three-dimensional angiography data set or a 3D angiography data set by itself. Of course, the angiography device can also have a storage device for caching the obtained three-dimensional angiography data set. However, this storage unit does not necessarily have to exist.

[0030] With regard to improvements and advantages of the angiography apparatus, what was stated above with regard to the image processing apparatus applies.

[0031] According to another aspect of the invention, a computer program having instructions is provided. When the instructions are executed by at least one image processing device of the above type, the instructions cause the image processing device to perform the method of the present invention. The instructions may be provided as program code. The program code may be provided as binary code or assembler and / or as source code in a programming language, such as C, and / or as a program script, such as Python.

[0032] In addition, an electronically readable data carrier storing the computer program is also provided. The data carrier may be a DVD, a memory stick, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will now be described in more detail with reference to the accompanying drawings, in which:

[0034] Figure 1 Schematic diagram showing the spatiotemporal fusion of two 4D angiography datasets;

[0035] Figure 2 A schematic block diagram showing an embodiment of the method of the present invention;

[0036] Figure 3 A schematic diagram showing an angiographic apparatus of the present invention; and

[0037] Figure 4 The time curve or time contrast curve of the contrast agent in the blood vessel (region) is shown. DETAILED DESCRIPTION

[0038] The embodiments described in more detail below represent preferred embodiments of the present invention. In the accompanying drawings, identical or functionally identical elements may be marked with identical reference symbols. Where appropriate, identical or functionally identical elements may not be repeatedly described with respect to different figures.

[0039] If it is mentioned within the scope of the present disclosure that components of the image processing device or angiography device of the present invention or its image processing unit are configured, constructed, designed or similarly used to perform or realize a specific function, achieve a specific effect or serve a specific purpose, this can be understood as, in addition to the principle or theoretical availability of the component or its applicability for the function, effect or purpose, through appropriate adjustment, programming, physical construction, etc., the component is able to specifically and actually perform or realize the function, achieve the effect or serve the purpose.

[0040] For a specific embodiment, the following steps may be performed:

[0041] a) Two or more contrast-enhanced 3D datasets are recorded for a patient with different contrast agent injection sites (usually different arterial supplies to the diseased vascular area, for example in the patient's brain).

[0042] b) 4D reconstruction of angiographic data sets (eg using a fluid confinement based method as described in DE 10 201 7200 489 A1).

[0043] c) Determine the temporal dynamics (eg, bolus arrival time, maximum darkening time, etc.) of each vessel voxel (or region of vessel voxels) in the reconstructed 4D image.

[0044] d) Identifying vessel voxels with contrast enhancement in two (or more) angiographic 4D images.

[0045] e) Temporally synchronize the 4D images (also referred to herein as 4D reconstructions) based on these common vessel voxels. The bolus arrival time (or other temporal metric, such as maximum darkening time) defines the "anchor time interval" used for temporal synchronization.

[0046] Figure 1 A workflow is shown for illustrating the spatiotemporal fusion of two angiographic 4D datasets or 4D reconstructions 1 and 2, respectively. The first 4D reconstruction is obtained from a first time-resolved 3D angiographic dataset of a patient (who received a first contrast agent at a first location). The second 4D reconstruction is obtained from a second time-resolved 3D angiographic dataset of the patient who received a second contrast agent at a second location different from the first location.

[0047] Figure 1 The 4D reconstructions 1 and 2 are shown in two dimensions. In a first contrast agent administration, on which the first 4D reconstruction 1 is based, contrast agent is injected into a first artery 3 . From this first artery 3 , the contrast agent flows into a first vessel section 4 of a vessel mass 5 .

[0048] In the selected view of the first 4D reconstruction 1, the temporal dynamics of the contrast agent within the vascular structure can be seen. Thus, the contrast agent reaches the first artery 3 approximately 150 milliseconds after injection. Approximately 200-300 milliseconds later, it reaches the finer vascular structures 6. Approximately 400 milliseconds later, the contrast agent is discharged in the venous outflow 7.

[0049] Similarly, the second 4D reconstruction 2 is based on the injection of contrast agent into a second artery 8. From this second artery 8, the blood or contrast agent flows into finer vascular structures 9 and then into the venous outflow 10. The time scale indicates when the contrast agent reaches the corresponding area.

[0050] Since the vascular mass 5 has many arteriovenous malformations and shunts, the contrast medium from the first artery 3 flows into the same vascular site as the contrast medium from the second artery 8. This vascular site can be referred to as a common vascular area 11. Therefore, in this common vascular area 11, the contrast medium enters the first artery 3 in the first contrast medium administration and enters the second artery 8 in the second contrast medium administration. For this reason, this common vascular area 11 is shown in both 4D reconstructions 1 and 2.

[0051] Since the common region 11 is reproduced in both 4D reconstructions 1 and 2, the two 4D reconstructions 1 and 2 can be spatially registered with each other. This means that the two 4D reconstructions 1 and 2 are spatially aligned and represent each other. Such spatial registration results in a spatially registered image 12 representing the vessel segments of the first 4D reconstruction 1 and the second 4D reconstruction 2 in different colors. The vessel parts affected by the two contrast agents appear in a mixed coloration (e.g. purple if the vessel structures of the first contrast agent become red and the vessel structures of the second contrast agent become blue).

[0052] Finally, the two 4D reconstructions 1 and 2 are temporally registered. This results in a temporally registered image 13, which reproduces the fusion of the two synchronized 4D reconstructions 1 and 2 in a simplified manner. In the temporally registered image 13, as in the spatially registered image 12, all vessel segments of the two contrast agent doses or the two 4D reconstructions 1 and 2 can be identified. However, for the fused 4D data set, the contrast agent flow is now synchronized, i.e. synchronized in time. In the present embodiment, the time point is set to the synchronized time of the contrast agent arrival at the common region 11. Thus, the fusion results in a three-dimensional video recording, which is based on two three-dimensional video recordings that are registered with each other in space and time.

[0053] Figure 2A more detailed flow of an example of a method for spatiotemporal fusion of time-resolved angiographic data sets according to the invention is shown in a flow chart. In a first step S1, a first time-resolved 3D angiographic data set of a patient is provided or detected or recorded. For this purpose, the patient received a first contrast agent at a first location. In a further step S2, a second time-resolved 3D angiographic data set of the patient is provided or recorded, wherein the patient received a second contrast agent at a second location different from the first location.

[0054] In step S3, a first 4D reconstruction is obtained from the first time-resolved three-dimensional angiographic data set. Likewise, in step S4, a second 4D reconstruction or a second 4D data set is obtained from the second time-resolved 3D angiographic data set.

[0055] In step S5, a common vascular region represented by the two 4D reconstructions or data sets is determined. This common vascular region of the patient is important for the subsequent spatial and temporal registration of the 4D data sets with one another. For this purpose, in step S6, a first time point or a first time curve associated with the occurrence of a first contrast agent bolus of a first contrast agent in the common vascular region is determined from the first 4D reconstruction. In the same way, a second time point or a second time curve associated with the occurrence of a second contrast agent bolus of a second contrast agent administration in the common vascular region is determined from the second 4D reconstruction.

[0056] In a further step S8, two 4D data sets, i.e. a first 4D reconstruction and a second 4D reconstruction, are synchronized based on the first time point and the second time point or the first time curve and the second time curve. Finally, in step S9, the two synchronized 4D reconstructions are fused. In this way, for example, two temporally consistent 3D video recordings are obtained in a common view.

[0057] Figure 3 An embodiment of an angiography device 14 according to the invention is schematically shown with an angiography unit 15 and an image processing unit 16. The angiography unit can have a C-arm 17 with an X-ray emitter 18 and a corresponding X-ray detector 19. In addition, the angiography unit 15 can have a control unit 20 for controlling the recording operation in order to acquire and detect corresponding time-resolved 3D angiography data sets, respectively, if necessary. Optionally, the angiography device has a storage unit 21 to store the detected time-resolved 3D angiography data sets and to make them available for subsequent image processing.

[0058] The image processing unit 16 of the angiography device 14 can also be implemented as a separate device with a storage unit 21 and / or a data interface, via which the corresponding 3D data set can be provided. In addition, the image processing unit 16 can have a calculation unit 22, with which a 4D reconstruction and a 4D data set are obtained from the 3D data set, respectively. In addition, a common vessel area and a first time point or a time curve of a first contrast agent bolus injection and a second time point or a time curve of a second contrast agent bolus injection in the common vessel area can be determined with the calculation unit 22. Finally, the calculation unit 22 is also designed to synchronize the two 4D reconstructions based on the time points and the time curves, respectively, and to fuse the two synchronized 4D reconstructions and, if appropriate, to display them on a screen 27.

[0059] Some details are described below that may be used to further improve the described methods and apparatus or should be considered where appropriate. A common vascular region may be described by a vascular voxel or a vascular voxel region and may be located on the venous side or the arterial side, depending on the two injection sites and the patient's vascular pathology. Ideally, early enhanced common voxels (or regions of common vascular voxels) are used for temporal registration to minimize inaccuracies, since in late enhanced voxels, contrast enhancement is reduced due to cross-flow of non-enhanced blood and dispersion of the contrast bolus.

[0060] Usually, two (or more) 4D angiographic data sets are already spatially registered or so to speak, because they are usually acquired during the same procedure and the patient has not moved or has hardly moved between the acquisitions. However, if necessary, one or more spatial registrations must be performed before the temporal registration or synchronization. Methods for spatial registration are known from the prior art.

[0061] In a special embodiment - as described above - more than two 4D angiographic data sets may be fused accordingly. In another embodiment, at least two 4D angiographic data sets are fused with at least one 3D angiographic data set (e.g. static CTA or MRA image). In another embodiment, at least two 4D angiographic data sets are fused with at least one 3D tomographic data set (e.g. static CT or MR image).

[0062] The method according to the invention can be used for vascular pathologies both outside and inside the brain. For example, the method can also be used to analyze distal AVMs of the limbs or face.

[0063] In a further embodiment, the time parameters used for the time synchronization of two or more 4D angiography data sets can be varied. The possibilities for these variations range from Figure 4 It can be seen that Figure 4The time curve of the contrast agent concentration in the blood vessel, i.e. the time-contrast curve, is shown. If necessary, a part of the time-contrast curve is also used for synchronization. The X-ray medium concentration is usually proportional to the X-ray attenuation or absorption coefficient μ. For example, the contrast agent is administered at time t=0. Then, a flooding phase occurs at a specified location in the blood vessel tree. The blackening or the absorption coefficient reaches a threshold value 24 at time BAT (bolus arrival time). This threshold value 24 is, for example, a detection threshold. This means that only from the detection threshold value 24 onwards, the contrast agent can be unambiguously detected. After the bolus arrival time BAT, the contrast agent concentration increases, so that the absorption coefficient μ increases according to the time curve 23 to a maximum value or peak value 25. This peak value 25 is reached at the peak time PT. Subsequently, the absorption coefficient of the specific blood vessel site decreases again continuously. The entire time curve 23 of the contrast agent concentration has a center of gravity 26, which is characterized by the center of gravity time CGT.

[0064] Therefore, some time parameters are given that can be used for the time synchronization of two or more 4D angiographic data sets, i.e. relative to two or more contrast agent doses:

[0065] a) Corresponding bolus arrival time

[0066] b) The corresponding peak time PT at the maximum contrast agent concentration

[0067] c) The corresponding center of gravity time CGT 23 of the center of gravity of the corresponding time-contrast curve

[0068] d) Selection of a synchronization point in time at which the normalized cross-correlation of the time-contrast curve 23 reaches a maximum

[0069] e) and other time parameters resulting from the time-contrast curve 23 can also be used for synchronization.

[0070] The above embodiments are based on a method of generating a combined 4D vascular map from multiple 4D images with different contrast agent injection locations. This enables a more complete image of the entire vascular system supplying an organ (e.g., the brain) or a vascular disease (e.g., AVM). In the case of AVM surgery, such spatiotemporally fused 4D images can be used to plan all possible arteriovenous embolization pathways based on a common data set.

Claims

1. A method for spatiotemporal fusion of time-resolved angiography datasets, It is characterized in that - providing (S1) a first time-resolved 3D angiographic dataset of a patient, said patient receiving a first contrast agent administration at a first location, - providing (S2) a second time-resolved 3D angiographic dataset of the patient, the patient receiving a second contrast agent administration at a second location different from the first location, - obtaining (S3) a first 4D reconstruction (1) from the first time-resolved 3D angiographic data set, - obtaining (S4) a second 4D reconstruction (2) from the second time-resolved 3D angiographic data set, - determining (S5) a common vascular region (11) of the patient represented by the two 4D reconstructions, - determining (S6) from the first 4D reconstruction (1) a first time point or a first time curve associated with the appearance of a first contrast agent bolus of a first contrast agent administration in the common vascular region (11), - determining (S7) from the second 4D reconstruction (2) a second time point or a second time curve associated with the appearance of a second contrast agent bolus of a second contrast agent administration in the common vascular region (11), - synchronizing (S8) the first 4D reconstruction (1) and the second 4D reconstruction (2) according to the first time point and the second time point or the first time curve and the second time curve; and - Fusion of two simultaneous 4D reconstructions.

2. The method according to claim 1, characterized in that The first time point and the second time point correspond to the arrival time point (BAT) of each contrast agent bolus in the common vascular region (11), respectively.

3. The method according to claim 1, characterized in that The first time point and the second time point correspond to the time point (PT) of the maximum concentration of each contrast agent bolus in the common blood vessel region (11), respectively.

4. The method according to claim 1, characterized in that The first time point and the second time point correspond to residence time points (CGT) of the respective centers of gravity (26) of the respective contrast agent boluses in the common vascular region (11).

5. The method according to claim 1, characterized in that: The time points at which the cross-correlation of the first time curve and the second time curve has a maximum are used for synchronization ( S8 ).

6. The method according to claim 1, characterized in that A plurality of vascular sites into which both the first contrast agent bolus and the second contrast agent bolus flow are determined from the 4D reconstruction, and the vascular sites first reached by the respective contrast agent boluses of the two contrast agent administrations are automatically determined as common vascular regions (11).

7. The method according to claim 1, characterized in that At least one further 4D reconstruction is synchronized and fused with the first 4D reconstruction and the second 4D reconstruction.

8. The method according to claim 1, characterized in that The first 4D reconstruction and the second 4D reconstruction are fused with the 3D angiography dataset.

9. The method according to claim 1, characterized in that The first 4D reconstruction and the second 4D reconstruction are fused with the three-dimensional tomographic data set.

10. An image processing device for spatiotemporal fusion of time-resolved angiography data sets, Features: - a storage unit (21) designed to o providing (S1) a first time-resolved 3D angiographic dataset of a patient receiving a first contrast agent administration at a first location, and o providing (S2) a second time-resolved 3D angiographic dataset of the patient, the patient receiving a second contrast agent administration at a second location different from the first location, and - an image processing unit (16) designed to o obtaining (S3) a first 4D reconstruction (1) from the first time-resolved 3D angiographic data set and obtaining (S4) a second 4D reconstruction (2) from the second time-resolved 3D angiographic data set, o determining (S5) the common vascular region (11) of the patient represented by the two 4D reconstructions, o determining (S6) from the first 4D reconstruction (1) a first time point or a first time curve associated with the appearance of a first contrast agent bolus of a first contrast agent administration in the common vessel region (11), o determining (S7) from the second 4D reconstruction (2) a second time point or a second time curve associated with the appearance of a second contrast agent bolus of a second contrast agent administration in the common vessel region (11), o synchronizing (S8) the first 4D reconstruction (1) and the second 4D reconstruction (2) according to the first and second time points or time curves, and ○ Fusion of two simultaneous 4D reconstructions.

11. An angiography apparatus for spatiotemporal fusion of time-resolved angiography data sets, Features: - an imaging unit (15) designed to o detecting a first time-resolved 3D contrast data set of a patient receiving a first contrast agent administration at a first location, and o detecting a second time-resolved 3D contrast data set of the patient, the patient receiving a second contrast agent administration at a second location different from the first location, and - an image processing unit (16) designed to o obtaining (S3) a first 4D reconstruction (1) from the first time-resolved 3D angiographic data set and obtaining (S4) a second 4D reconstruction (2) from the second time-resolved 3D angiographic data set, o determining (S5) the common vascular region (11) of the patient represented by the two 4D reconstructions, o determining (S6) from the first 4D reconstruction (1) a first time point or a first time curve associated with the appearance of a first contrast agent bolus of a first contrast agent administration in the common vessel region (11), o determining (S7) from the second 4D reconstruction (2) a second time point or a second time curve associated with the appearance of a second contrast agent bolus of a second contrast agent administration in the common vessel region (11), o synchronizing (S8) the first 4D reconstruction (1) and the second 4D reconstruction (2) according to the first time point and the second time point or the first time curve and the second time curve, and ○ Fusion of two simultaneous 4D reconstructions.

12. A computer program product, comprising a computer program, which, when executed on the image processing apparatus of claim 10, performs the steps of the method of any one of claims 1 to 9.

13. An electronically readable data carrier comprising a computer program product according to claim 12.

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