Providing feedback during balloon angioplasty

Abstract

A system for providing feedback during balloon angioplasty is provided. The system includes one or more processors configured to: receive projection image data representing a balloon in a blood vessel; and output information for comparing a state of expansion of the balloon represented in the projection image data to a simulated state of expansion of the balloon based on a shape of the balloon in the simulated state of expansion (140) and based on a shape of the balloon represented in the projection image data (150) (160, 170).

Description

Technical Field

[0001] This disclosure relates to providing feedback during balloon angioplasty. A system, a computer-implemented method, and a computer program product are disclosed. Background Technology

[0002] Balloon angioplasty, also known as percutaneous transluminal angioplasty (PTA), is a medical procedure in which a balloon is inflated within a blood vessel to expand its lumen, thereby increasing blood flow through the vessel. Balloon angioplasty is performed on blood vessels that have narrowed due to conditions such as atherosclerosis (i.e., the buildup of plaque in the blood vessels). Balloon angioplasty is often performed in combination with a stent. A stent is a device used in balloon angioplasty where a balloon is inflated within a stent, which in turn expands the lumen of the vessel. The stent remains in the vessel to support the lumen in its expanded state, preventing subsequent collapse. Balloon angioplasty can be performed on both arteries and veins. It can be performed on various parts of the anatomical structure, including the heart and brain, and also in peripheral regions such as the legs and kidneys.

[0003] However, during balloon angioplasty, physicians face challenges in determining whether the vessel lumen has been adequately dilated for the procedure to be successful. For example, when treating calcified lesions with balloon angioplasty, calcium deposits within the lesion affect balloon dilation. As the balloon dilates, it ruptures the calcium deposits, pushing them to one side. However, calcium deposits are often asymmetrically distributed around the vessel lumen. This asymmetrical balloon dilation makes it difficult for physicians to assess whether the vessel lumen has been adequately dilated.

[0004] Therefore, improved feedback is needed during balloon angioplasty. Summary of the Invention

[0005] According to one aspect of this disclosure, a system for providing feedback during balloon angioplasty is provided. The system includes one or more processors configured to:

[0006] Receive projection image data representing a balloon in a blood vessel;

[0007] Based on the shape of the balloon in a simulated dilated state within the blood vessel, and based on the shape of the balloon represented in the projected image data, information is output for comparing the dilated state of the balloon represented in the projected image data with the simulated dilated state.

[0008] The output of the information includes the value of an output metric, which represents the difference between the shape of the balloon in the simulated expansion state and the shape of the balloon represented in the projected image data (120).

[0009] Since the information used to compare the balloon's expansion state as represented in the projected image data with the simulated expansion state is determined based on the balloon's shape in the simulated expansion state within the blood vessel, the system provides a reliable assessment of the balloon's expansion state as represented in the projected image data, particularly by means of an objective measure representing the difference between the simulated expansion state and the "current" expansion state of the balloon as represented in the projected image data. Therefore, the system provides reliable feedback on the progress of balloon angioplasty.

[0010] Further aspects, features, and advantages of this disclosure will become apparent from the following description of examples taken with reference to the accompanying drawings. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating an example of a system 100 for providing feedback during balloon angioplasty according to some aspects of this disclosure.

[0012] Figure 2 This is a flowchart illustrating an example of a computer-implemented method for providing feedback during balloon angioplasty according to some aspects of this disclosure.

[0013] Figure 3 This is an example of projected image data 120 of a balloon 130 in a blood vessel, according to some aspects of this disclosure.

[0014] Figure 4 The illustration shows a first example of output information 160, 170 for comparing the balloon expansion state represented in the projected image data with the simulated expansion state, according to some aspects of the present disclosure.

[0015] Figure 5 The illustration shows a second example of output information 160, 170 for comparing the balloon expansion state represented in the projected image data with the simulated expansion state, according to some aspects of the present disclosure.

[0016] Figure 6 The illustration includes balloon 130, which is one aspect of this disclosure. VP The first graphical representation of the virtual projection is a schematic diagram of an example of the generated 140.

[0017] Figure 7 An example of a recommended perspective α1 for visualizing calcium deposits in blood vessels, according to some aspects of this disclosure, is illustrated. Detailed Implementation

[0018] Examples of this disclosure are provided with reference to the following description and accompanying drawings. In this specification, for purposes of explanation, numerous specific details of certain examples are set forth. References to “example,” “implementation,” or similar language in the specification mean that a feature, structure, or characteristic described in connection with that example is included in at least one example. It should also be understood that a feature described with respect to one example may also be used in one example, and for the sake of brevity, not all features are necessarily repeated in every example. For example, features described with respect to a computer-implemented method may be implemented in a corresponding manner in computer program products and systems.

[0019] In the following description, examples of systems for providing feedback during balloon angioplasty are referenced. In some examples, a balloon angioplasty procedure performed on an artery of the heart is referenced. However, it should be understood that arteries and the heart are used only as examples. Generally, the system can be used to provide feedback during a balloon angioplasty procedure performed on any type of blood vessel, and the blood vessel can be in any anatomical region. For example, the system can be used to provide feedback during a balloon angioplasty procedure performed on an artery or vein, and the blood vessel can be in the heart, brain, or peripheral regions such as the leg, kidney, etc.

[0020] Note that the computer-implemented methods disclosed herein can be provided as a non-transitory computer-readable storage medium including computer-readable instructions stored thereon, which, when run by at least one processor, cause the at least one processor to perform the method. In other words, the computer-implemented methods can be implemented in a computer program product. The computer program product can be provided by dedicated hardware or hardware capable of running software associated with appropriate software. When provided by a processor, the functionality of the method features can be provided by a single dedicated processor, a single shared processor, or multiple individual processors (some of which may be shared). The functionality of one or more method features can be provided, for example, by a processor shared within a networked processing architecture such as a client / server architecture, a peer-to-peer architecture, the Internet, or the cloud.

[0021] The explicit use of the terms "processor" or "controller" should not be construed as referring specifically to hardware capable of running software, and may implicitly include, but is not limited to, digital signal processor (DSP) hardware, read-only memory (ROM) for storing software, random access memory (RAM), non-volatile storage devices, etc. Furthermore, examples of this disclosure may take the form of a computer program product accessible from a computer-usable storage medium or a computer-readable storage medium, the computer program product providing program code for use by or in conjunction with a computer or any instruction-running system. For the purposes of this description, a computer-usable storage medium or a computer-readable storage medium can be any means capable of including, storing, communicating, propagating, or transmitting a program for use by or in conjunction with an instruction-running system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system or device or a propagation medium. Examples of computer-readable media include semiconductor or solid-state memory, magnetic tape, removable computer disks, random access memory (RAM), read-only memory (ROM), rigid disks, and optical disks. Current examples of optical discs include CD-ROM (Read-Only Memory), CD-R / W (Read / Write), and Blu-ray. TM and DVD.

[0022] It should also be noted that some operations described as being performed by one or more processors of the system disclosed herein can be implemented using artificial intelligence techniques. Suitable techniques may include machine learning techniques, deep learning techniques, and neural networks. For example, one or more neural networks can be trained in a supervised or, in some cases, unsupervised manner to implement operations performed by one or more processors.

[0023] As mentioned above, there is a need to provide improved feedback during balloon angioplasty.

[0024] Figure 1 This is a schematic diagram illustrating an example of a system 100 for providing feedback during balloon angioplasty according to some aspects of this disclosure. Figure 2 This is a flowchart illustrating an example of a computer-implemented method for providing feedback during balloon angioplasty according to some aspects of this disclosure. Note that it is described as being performed by... Figure 1 The operations performed by one or more processors 110 of the illustrated system 100 can also be performed in Figure 2 Execute in the method illustrated. Similarly, regarding the reference... Figure 2 The methods described can also be described by Figure 1 One or more processors 110 of the illustrated system 100 execute. (Reference) Figure 1 and Figure 2 The system 100 for providing feedback during balloon angioplasty includes one or more processors 110, which are configured to:

[0025] S110 receives projection image data 120 representing the balloon 130 in the blood vessel;

[0026] Based on the shape 140 of the balloon in a simulated expansion state in the blood vessel, and based on the shape 150 of the balloon 130 represented in the projection image data 120, information 160, 170 for comparing the expansion state of the balloon 130 represented in the projection image data 120 with the simulated expansion state is output in S120.

[0027] Since the system 100 determines information 160, 170 for comparing the expansion state of the balloon 130 represented in the projection image data 120 with the simulated expansion state based on the shape 150 of the balloon 130 in a simulated expansion state in the blood vessel, the system 100 provides a reliable assessment of the expansion state of the balloon represented in the projection image data. Therefore, the system 100 provides reliable feedback on the progress of balloon angioplasty.

[0028] The operations performed by one or more processors 110 of system 100 are described in more detail below.

[0029] In operation S110, projected image data 120 is received.

[0030] The projected image data 120 received in operation S110 can be generated by a projection X-ray imaging system. This system can be an energy-spectrum projection X-ray imaging system. The energy-spectrum projection X-ray imaging system generates X-ray attenuation data representing X-ray attenuation within multiple different energy intervals. The X-ray attenuation data generated by the energy-spectrum projection X-ray imaging system can be processed, for example, using various material decomposition algorithms to distinguish media that have similar X-ray attenuation values ​​when measured within a single energy interval and would be indistinguishable in X-ray attenuation data obtained using a conventional projection X-ray imaging system. Therefore, the X-ray attenuation data generated by the energy-spectrum projection X-ray imaging system can be processed to provide projection images with improved material specificity for materials such as blood vessel walls, plaque components, contrast agents, tissues, and bones.

[0031] The projected image data 120 received in operation S110 represents the balloon 130 in the blood vessel.

[0032] Projected image data 120 can represent various types of balloons. By way of examples, the balloon can be a compliant balloon, a non-compliant balloon, an "above-the-line" balloon, a rapid-change balloon, a balloon including serrated lines or blades, etc. Typically, a balloon can be inflated by injecting gas (such as air or liquid) into it. Figure 3 This is an example of projected image data 120 of a balloon 130 in a blood vessel, according to some aspects of this disclosure. Figure 3 In the illustrated example, the projection image data 120 is shown in the form of an X-ray projection image. The balloon 130 is filled with a liquid comprising a contrast agent. The contrast agent enhances the visibility of the balloon in the X-ray projection image. Some balloons also include one or more radiopaque markers for further enhancing their visibility in the X-ray projection image. For example, radiopaque markers may be positioned at the axial end of the balloon.

[0033] exist Figure 3 In the illustrated example, balloon 130 is in a partially inflated state, and the projected shape of the balloon is visible in the X-ray projection image. During angioplasty, the pressure inside balloon 130 increases. This pressure causes the balloon to inflate, thereby exerting dilatational forces on the surrounding medium (such as the vessel wall) and any plaque that may be present within the vessel. When the lumen has been sufficiently dilated, the pressure inside the balloon decreases, and the balloon contracts. In some cases, the balloon inflates and contracts only once to achieve the desired amount of vascular dilation. In other cases, the balloon inflates and contracts multiple times. After the lumen has been dilated, examinations can be performed in which contrast agent is injected into the vascular system and angiographic images are acquired to verify the amount of vascular dilation achieved.

[0034] Continuing with operation S110, the projected image data 120 received in operation S120 can be received from various sources. For example, it can be received from the aforementioned (energy spectral) projection X-ray imaging system. Figure 1 In the illustrated example, projected image data 120 is received from the projection X-ray imaging system 230.

[0035] Typically, the projected image data 120 received in operation S110 can be received by one or more processors 110 via any form of data communication, including wired, wireless, or fiber optic communication. As examples, when using wired data communication, communication can occur via electrical signals transmitted over a cable. When using wireless data communication, communication can occur via RF or infrared signals. When using fiber optic data communication, communication occurs via optical signals transmitted over an optical fiber.

[0036] Now for reference Figure 1The illustrated operation S120 involves outputting information 160 and 170 to compare the balloon 130's expansion state as shown in the projected image data 120 with a simulated expansion state. The output information is based on the balloon's shape 140 in the simulated expansion state within the blood vessel and on the balloon 130's shape 150 as shown in the projected image data 120.

[0037] The simulated expansion state can refer to any expansion state of the balloon. For example, the simulated expansion state can be a partially expanded state or a fully expanded state. In operation S120, various techniques can be used to determine the shape 140 of the balloon in the simulated expansion state. For example, models such as finite element models or machine learning techniques can be used to simulate the shape of the balloon in the expanded state. The interventional physician can also directly input some desired shapes or characteristics that can be taken into account to generate the simulated expansion state.

[0038] In the former case, the shape of the balloon in a simulated dilated state can be determined based on image data representing the blood vessel. For example, volumetric image data representing the blood vessel can be acquired, and this volumetric image data is used to construct a geometric model of the blood vessel. For example, the volumetric image data could be (spectral) CT image data, or coronary computed tomography angiography (CCTA) data, or magnetic resonance imaging (MRI) data, 3D ultrasound image data, intravascular ultrasound (IVUS) image data, or optical coherence tomography (OCT) image data. The volumetric image data can be segmented to provide distinctions between media such as the blood vessel, the vessel wall, and any plaque components that may be present within the vessel. For example, CT image data can be segmented based on (Henness units) attenuation values ​​to differentiate between such media. MRI image data can be similarly used to differentiate such media. The material properties of the vessel wall (e.g., stiffness, elasticity) and any plaque components within the vessel (e.g., plaque, calcified plaque, cholesterol, fibrin, etc.) can then be assigned to the relevant materials. Alternatively, the motion of structures such as the vessel wall can be analyzed in time-lapse CT image data or time-lapse MRI data to extract their corresponding material properties. A geometric model representing the balloon can be constructed similarly. The balloon can be modeled using its known dimensions and known material properties (e.g., its elasticity). Finite element simulations can then be performed using the balloon's geometric model within the vessel's geometry to determine the balloon's shape in a simulated expanded state within the vessel.

[0039] In the latter case, machine learning techniques (such as neural networks) can be used to determine the shape of the balloon in a simulated expansion state. In this case, image data representing the blood vessel can be input into the machine learning model, and in response, the machine learning model predicts the shape of the balloon for a specified (e.g., partially, fully) expansion state. The image data may include the aforementioned projected image data 120 and / or volumetric image data. Training data for training the machine learning model may include image data of the balloon in a blood vessel representing angioplasty, wherein the balloon has been expanded to different expansion states.

[0040] Typically, the simulations described above can be performed before the angioplasty procedure (e.g., during the planning phase), or alternatively, they can be performed during the angioplasty procedure itself.

[0041] In one example, one or more processors 110 are used to determine the shape 140 of the balloon in a simulated inflated state. In this example, the one or more processors 110 are configured to:

[0042] Receive volumetric image data 180 representing blood vessels; and

[0043] A virtual balloon 130 was used to simulate the expansion of a blood vessel using volumetric image data 180. V The shape is configured to provide the shape 140 of the balloon in a simulated expanded state.

[0044] In this example, the shape 140 of the balloon in the simulated expansion state can be determined using the aforementioned model or machine learning techniques. For example, volumetric image data can be generated by various types of volumetric imaging systems, such as (spectral) CT imaging systems, MRI systems, or 3D ultrasound imaging systems. The shape 140 of the balloon in the simulated expansion state can be determined based on various balloon parameters. For example, the shape 140 of the balloon in the simulated expansion state can be determined based on balloon parameters such as balloon size, balloon elasticity, balloon pressure, etc. Balloon parameters can be determined from a database storing balloon parameters for multiple balloon types. Alternatively, the balloon parameters can be provided by the user. In the latter case, one or more processors 110 can receive user input representing one or more balloon parameters for the virtual balloon; and the balloon parameters can be used to perform virtual balloon 130 simulating expansion in a blood vessel. V Shape manipulation.

[0045] In one example, the shape 140 of the balloon in a simulated expanded state in a blood vessel represents the shape of the balloon in a simulated expanded state within a virtual stent in a blood vessel.

[0046] In this example, the shape of the balloon is determined based on the constraints imposed by the stent. Therefore, it provides the balloon shape during the angioplasty procedure performed in conjunction with the stent. The shape of the balloon in a simulated expansion state within a virtual stent in the blood vessel can be determined by including a geometric model of the stent in the simulation described above, or by training a machine learning model using training data that includes image data representing the balloon within the stent in the blood vessel during the angioplasty procedure, wherein the balloon has expanded to different expansion states.

[0047] In one example, a virtual balloon 130 simulates the expansion of a blood vessel. V The operation of shaping the balloon 140 to provide the shape in a simulated inflated state includes:

[0048] Volumetric image data 180 was used to simulate the rupture of calcium deposits 190 within blood vessels; and

[0049] The shape 140 of the balloon in the simulated expansion state was determined based on the simulated rupture of calcium deposits 190.

[0050] The aforementioned volumetric image data 180 can be used to simulate the rupture of calcium deposits. For example, in one example, a virtual balloon 130 simulating dilation in a blood vessel. V Shape manipulation includes:

[0051] Analyze volumetric image data 180 to identify i) the wall 210 of the blood vessel, and ii) one or more plaque components 190, 220 within the blood vessel;

[0052] Mechanical parameters are assigned to i) the wall 210 of the blood vessel, and ii) each of one or more plaque components 190, 220 within the blood vessel; and

[0053] Using the assigned mechanical parameters, the dilated virtual balloon 130 in the blood vessel is determined based on i) the identified wall 210 of the blood vessel and ii) one or more plaque components 190, 220 within the blood vessel. V The shape.

[0054] As described above, when the balloon dilates during angioplasty, it ruptures calcium deposits, pushing them to one side. However, calcium deposits are often asymmetrically distributed around the vascular lumen. Calcium deposits cause asymmetrical balloon dilation. In such cases, it is difficult for physicians to assess whether the vascular lumen has been adequately dilated. By determining the balloon shape 140 in a simulated dilated state based on simulated rupture of calcium deposits 190, this example provides an accurate simulated shape of the balloon after calcium deposit rupture.

[0055] In this example, the operation of analyzing volumetric image data may include assigning a material type to the image region represented in the volumetric image data based on its (Henness units) X-ray attenuation value. One or more plaque components may include plaques, calcified plaques (i.e., calcium deposits), etc. For example, calcium deposits can be distinguished from other plaque components and the vessel wall due to their relatively high (Henness units) X-ray attenuation value. Similarly, other plaque components can be distinguished from the vessel wall based on their relatively high (Henness units) X-ray attenuation values. The assigned mechanical parameters may include elastic values, fracture stress values, etc. The assigned mechanical parameters can be used in the aforementioned finite element simulation to determine the expansion of the virtual balloon 130 in the blood vessel. V The shape of the balloon. The allocated mechanical parameters can also be used to evaluate the stress distribution in calcium deposits related to fracture stress. The stress distribution can be used to determine the balloon's expansion state at which it causes the calcium deposit to rupture.

[0056] Continue to refer to Figure 1 The illustrated operation S120 involves outputting information 160 and 170 to compare the inflation state of the balloon 130 represented in the projected image data 120 with the simulated inflation state. The output information is based on the shape 140 of the balloon in the simulated inflation state in the blood vessel and on the shape 150 of the balloon 130 represented in the projected image data 120.

[0057] In operation S120, information 160, 170 can be output in various forms. For example, the information can be output in the form of a graphical representation, or as text or icons. In operation S120, information can be output in various ways. For example, the information can be output to a display (such as...) Figure 1 The output may be sent to a display 240 (as shown in the illustration), or to a virtual / augmented reality display device, or to a printer, or to a computer-readable storage medium, or to the Internet, or to the cloud, etc.

[0058] In one example, the information 160, 170 output by S120 for comparing the inflation state of the balloon 130 represented in the projected image data 120 with the simulated inflation state includes:

[0059] The first graphic representation of the output balloon is 140, where the balloon is in a simulated inflated state; and

[0060] The output balloon 130 is represented by a second graphic representation 150, wherein the balloon is in its expanded state as shown in the projected image data 120.

[0061] refer to Figure 4 and Figure 5 Describe this example. Figure 4The illustration shows a first example of output information 160, 170 for comparing the balloon expansion state represented in the projected image data with the simulated expansion state, according to some aspects of the present disclosure. Figure 5 The illustration shows a second example of output information 160, 170 for comparing the balloon expansion state represented in the projected image data with the simulated expansion state, according to some aspects of the present disclosure. Figure 5 The example shown in the figure represents a ratio Figure 4 The stage shown in the diagram is the later balloon dilation stage.

[0062] exist Figure 4 and Figure 5 In the illustrated example, the first graphic representation 140 of the balloon includes the outline of the balloon's projected shape 140 corresponding to a simulated dilated state within a blood vessel. This outline can be determined using image processing techniques, as described in more detail below. Figure 4 and Figure 5 In the illustrated example, the second graphic representation 150 of the balloon 130 includes a contour corresponding to the shape 150 of the balloon in the projected image data 120. This contour can be determined by segmenting the projected image data. Various segmentation techniques can be used for this purpose, such as, for example, model-based segmentation, watermark-based segmentation, region growing, level sets, graph cutting, and neural networks.

[0063] exist Figure 4 and Figure 5 In the illustrated example, the graphic representation of the balloon is displayed as a superimposition on the projected image data 120. However, it should be noted that the graphic representation can alternatively be displayed in different ways. For example, the outline of the balloon's shape can be displayed without being superimposed on the projected image data 120, or the outline of the balloon's shape 140 in the simulated inflated state can simply be superimposed on the projected image data 120. Instead of... Figure 4 and Figure 5 The illustrations show balloons registered to each other, and the first graphic representation 140 of the balloon and the second graphic representation 150 of the balloon 130 can be displayed in different ways. For example, they can be displayed side by side.

[0064] In one example, one or more processors 110 are configured to output one or more additional graphical representations of the balloon, wherein the balloon is in one or more additional simulated expansion states. As mentioned above, a simulated expansion state can refer to any expansion state of the balloon. For example, a simulated expansion state can be a partially expanded state or a fully expanded state. The graphical representation can show the progressive expansion of the balloon in a series of simulated expansion states. Such a graphical representation allows the physician to confirm that the shape of the balloon expands as expected at multiple time points during the angioplasty procedure.

[0065] In one example, the first graphical representation 140 of the balloon represents a blood vessel and a calcium deposit 190, and the operation S120 of outputting information 160, 170 for comparing the expansion state of the balloon 130 represented in the projected image data 120 with a simulated expansion state includes outputting an indication of the location of the simulated rupture of the calcium deposit. This example can be used in conjunction with an example simulating the rupture of the calcium deposit 190 within a blood vessel. In this example, for example, the location of the simulated rupture of the calcium deposit can be indicated by highlighting the first or second graphical representation with color or markers.

[0066] In one example, operation S120, which outputs information 160, 170 for comparing the expansion state of balloon 130 represented in projected image data 120 with a simulated expansion state, includes outputting a value of a metric quantifying the simulated rupture of calcium deposit 190. This example can be used in conjunction with an example simulating the rupture of calcium deposit 190 within a blood vessel. For example, in this example, the metric could represent a change in calcium load, or the total number of fragments generated by the simulated rupture of calcium deposit 190, or the maximum size of the fragments generated by the simulated rupture of calcium deposit 190.

[0067] In one example, the first graphic representation 140 of the balloon represents a blood vessel, and the first graphic representation 140 includes the distinction between the wall 210 of the blood vessel and at least one of one or more plaque components 190, 220.

[0068] In this example, volumetric image data can be used to determine the distinction between the vessel wall 210 and at least one of one or more plaque components 190, 220. For example, if the volumetric image data represents an X-ray attenuation value in (Henle units), that (Henle units) X-ray attenuation value can be used to differentiate these media. For example, the distinction can be provided in a first or second graphical representation by using different colors, different shading, or different markers or icons to depict the vessel wall 210 and at least one of one or more plaque components 190, 220.

[0069] In one example, the balloon in the first graphic representation 140 is registered to the balloon in the second graphic representation 150. This arrangement is... Figure 4 and Figure 5 The diagram shows how registering the balloons together helps in accurately comparing their shapes. Various image processing techniques can be used to perform registration. For example, if the viewing angle of the projection imaging system used to acquire projected image data is known, the known viewing angle can be used to generate a projection of volumetric image data 180 from the same viewing angle. This can be achieved by attaching an optical tracking system to... Figure 1The illustrated projection X-ray imaging system 230 uses a source-detector arrangement and an optical tracking system to track patient landmarks or reference markers placed on the patient to determine the viewing angle. Patient landmarks or reference markers can be used to provide a 3D mesh defining the patient's surface, and thus they provide a correspondence between the coordinate system of the projection X-ray imaging system and the volumetric image data. Alternatively, an iterative technique based on finding the best fit between the volumetric image data and the projection of the projection image data 120 can be used to determine the viewing angle relative to the volumetric image data 180, from which the projection image data is obtained. This technique may include acquiring projection image data from multiple angles relative to the object to constrain the fitting process.

[0070] As disclosed herein, the operation of outputting information 160, 170 for comparing the expansion state of balloon 130 represented in the projected image data 120 with the simulated expansion state includes: outputting the value of a metric 170 that represents the difference between the shape 140 of the balloon in the simulated expansion state and the shape 150 of the balloon 130 represented in the projected image data 120.

[0071] The metrics provided here offer feedback to the physician, enabling the physician to objectively compare the current shape 150 of the balloon 130 with the simulated expansion state and determine when the simulated expansion state of the balloon has been reached. By way of examples, this difference could be a difference in balloon volume, or a difference in balloon surface area, or a (maximum) difference in balloon cross-sectional area, or a (maximum) difference in balloon diameter.

[0072] In one example, projected image data 120 is acquired from multiple perspectives relative to the balloon, and the shape of the balloon represented in the projected image data is established using the projected image data. Therefore, the current balloon shape 150 can be determined with relatively high accuracy.

[0073] Therefore, the difference between the simulated shape 140 and the current shape 150 is evaluated based on projected image data acquired from multiple perspectives. For example, the surface of the bladder can be estimated from the projected image data by fitting a mesh to the projected image data acquired from multiple perspectives. The surface of the mesh can then be fitted to the simulated shape of the bladder obtained from the volumetric image data. This improves the accuracy of the difference evaluated in this example.

[0074] In some examples, the shape 140 of the balloon in a simulated dilated state within a blood vessel can correspond to a planned dilated state. In this case, the metric represents the fraction of the planned dilated state that has been reached, or the remaining dilated amount required before reaching the planned dilated state. This example is shown via labels “67% of planned dilated state” and “97% of planned dilated state”, respectively. Figure 4 and Figure 5 The figure is shown in the upper right part. This metric can be combined with the first and second graphical representations of the balloon in operation S120 (i.e., in...). Figure 4 and Figure 5 The output can be in the manner illustrated in the diagram. Alternatively, the metric can be output instead of these graphical representations. In other words, the text or icon representing the value can be output, for example, to... Figure 1 The illustrated display device 240.

[0075] In a relevant example, the operation of outputting information 160 and 170 in S120 to compare the inflation state of balloon 130 represented in the projected image data 120 with the simulated inflation state includes: outputting an indication that the balloon angioplasty procedure is complete based on the value of a threshold-related metric 170. For example, if the inflation state of balloon 130 represented in the projected image data 120 has exceeded thresholds such as 90%, 95%, and 98%, the system 100 can output an indication that the balloon angioplasty procedure is complete.

[0076] In one example, the first graphic representation 140 includes a balloon 130. VP Virtual projection. An expanded virtual balloon 130 is simulated using volumetric image data 180 through projection. V The shape is used to generate a virtual projection of the balloon, such that the first graphic representation 140 is the balloon 130. VP Represented from the same perspective α1 as the balloon 130 in the second graphic representation 150.

[0077] This example is in Figure 6 The diagram in the middle shows, Figure 6 The illustration includes balloon 130, which is one aspect of this disclosure. VP The first graphical representation of the virtual projection is a schematic diagram of an example of the generated 140. Figure 6 The central volumetric image data 180 represents the left branch of the coronary tree. The left branch of the coronary tree includes multiple vessels 270. 1..i This includes the left anterior descending artery (LAD). Volumetric image data was used to simulate a virtual balloon 130 expanding within the LAD using the aforementioned technique. V The shape. In Figure 6 The lower part illustrates the projected image data 120. The projected image data includes a balloon 130 and also includes multiple blood vessels 270. 1..i This includes the LAD. Projected image data is generated by a projection X-ray imaging system with a viewing angle relative to the balloon. It uses data from a virtual X-ray source 230. S The emitted virtual X-rays will mathematically expand into a virtual spherical balloon of 130. V The shape is projected onto the virtual X-ray detector 230 D Above. This is in Figure 6 The image shows a virtual X-ray (R) pattern. Within the expanded virtual balloon 130... V The ray tracing operation performed on the balloon resulted in 130 VP Virtual projection. One or more blood vessels represented in volumetric image data 180 270 1..i It can also be projected during this operation to provide projected blood vessels 270. P 1..i ,like Figure 6 As shown in the diagram.

[0078] Expanded virtual balloon 130 V The shape is projected so that the first graphic representation of the balloon 130 in 140 is... VP It is represented from the same viewpoint α1 as the balloon 130 in the second graphic representation 150. This operation can be performed based on a known correspondence between the viewpoint used to obtain the projected image data 120 and the reference orientation relative to the volumetric image data. For example, the optical tracking system described above can be used to provide a correspondence between the coordinate system of the projected X-ray imaging system and the volumetric image data.

[0079] In one example, volumetric image data 180 is used to recommend the viewing angle for acquiring projected image data 120. In this example, one or more processors 110 are configured to:

[0080] The recommended viewing angle α1 for acquiring projection image data 120 is determined based on volumetric image data 180; and

[0081] Output the value of the recommended viewpoint α1.

[0082] The recommended perspective can be determined based on various factors. For example, it can be based on one or more of the following: providing balloon 130 in the first graphic representation 140. VP Minimal perspective shortening provides optimal visualization of calcium deposits in blood vessels, maximizes visualization of stenosis asymmetry, and provides the minimum total number of blood vessels superimposed on stenosis in volumetric image data 180. These factors can be modeled and weighted using volumetric image data 180 to determine the recommended perspective.

[0083] Figure 7 An example of a recommended perspective α1 for visualizing calcium deposits in blood vessels, according to some aspects of this disclosure, is illustrated. Figure 7 The illustration shows a view of volumetric image data 180 along an axis of a blood vessel including calcium deposits 190 and non-calcium plaque components 220. The vessel wall 210 surrounds the calcium deposits 190 and non-calcium plaque components 220. The calcium deposits 190 appear as a bright white area due to their relatively higher X-ray attenuation compared to the non-calcium plaques. The vessel lumen 280 is also... Figure 7 The diagram shows the recommended viewing angle α1 optimized based on the distribution of calcium deposit 190 relative to the vessel centerline. The recommended viewing angle α1 can be chosen such that, for at least the portion of the vessel corresponding to the axial extent of the balloon, the calcium deposit 190 is distributed with maximum asymmetry relative to the vessel centerline. Therefore, at the recommended viewing angle, the calcium deposit 190 can be located on one side of the vessel centerline, such as... Figure 7 As shown in the diagram.

[0084] The output value of the recommended viewing angle α1 can be used to acquire the projected image data 120 received in operation S110. For example, after outputting the value of the recommended viewing angle α1, the user can adjust the viewing angle α of the projection imaging system 230 to the recommended viewing angle α1, or one or more processors 110 of the system 100 can automatically adjust the viewing angle α to the recommended viewing angle α1 before acquiring the projected image data 120.

[0085] In one example, one or more processors 110 are configured as follows:

[0086] Outputs an indication of the recommended type of stent for stent implantation in the said blood vessel;

[0087] and / or

[0088] Outputs an indication of recommended values ​​for the size of the stent used for stent implantation in the said blood vessel.

[0089] In this example, the type of stent output can refer to the stent manufacturer or model. The stent size can refer to the stent's length and / or diameter and / or grid size. Recommended stent size types and / or values ​​can be determined from volumetric image data 180. For example, the location of a stenosis in a blood vessel can be identified automatically or based on user input, and a recommended stent diameter can be determined using the diameter of the vessel proximal or distal to the stenosis. The length of the stenosis can be used to determine a recommended stent length. A recommended stent grid size can be determined based on the distribution of calcium deposits(s) along the stenosis(s).

[0090] Typically, the projection image data 120 received in operation S110 may include a single static image representing a balloon 130 in a blood vessel, or it may include a live sequence of images representing a balloon 130 in a blood vessel. In the former case, the output operation S120 is performed on the single static image. Subsequent static images can then be received, and the output is performed again for each subsequent static image. In the latter case, the projection image data 120 includes a live sequence of images representing a balloon 130 in a blood vessel, and output S120 is performed for the current image in the live sequence, and output S120 is repeated for subsequent current images in the live sequence. For example, the live sequence of images may be fluorescence fluoroscopy X-ray images.

[0091] As can be understood, in cases where the projected image data 120 includes a live sequence of images representing a balloon 130 within a blood vessel, the balloon can undergo significant motion. For example, if the blood vessel is located within the heart, the balloon will move in response to the heart's beating. This presents a significant challenge in tracking the progress of angioplasty procedures, as this motion makes it difficult to visualize the balloon's current expansion state as it moves. Several examples of systems are described below that address the challenges posed by such cardiac motion.

[0092] In one example, volumetric image data 180 represents blood vessels at the cardiac phase. In this example, the operation of output S120 for comparing the expansion state of balloon 130 represented in projected image data 120 with the simulated expansion state is selectively performed for the current image from the live sequence, which represents blood vessels at the cardiac phase represented in volumetric image data 180.

[0093] The output is selectively performed on the current image of the blood vessels at the cardiac phase represented in the volumetric image data 180 of the live sequence, limiting the output to images where the balloon is in a similar location. This reduces the influence of cardiac motion on the output, thereby helping to provide a clearer comparison between the balloon's expansion state represented in the projected image data and the simulated expansion state. In this example, the cardiac phase could be, for example, the end of diastole, or the end of systole, or an intermediate cardiac phase between systole and diastole. The cardiac phase can be determined by analyzing the projected image data 120. For example, the cardiac phase can be determined based on the movement of portions of the heart in the projected image data. Alternatively, an electrocardiogram (ECG) signal can be acquired during the acquisition of the projected image data to determine the cardiac phase.

[0094] In another example, the operation of outputting information 160, 170 for comparing the expansion state of the balloon 130 represented in the projected image data 120 with the simulated expansion state includes:

[0095] Register blood vessels at one or more different cardiac phases in the current image of the live sequence to the blood vessels at the cardiac phases represented in the volumetric image data 180; and

[0096] Output information 160 and 170 is generated based on the registered blood vessels.

[0097] In this example, the registration operation has the effect of spatially aligning the balloon in the current image with the balloon in the volumetric image data 180. As in the previous example, this also reduces the influence of cardiac motion on the output, thereby helping to provide a clearer comparison between the balloon's expansion state represented in the projected image data and the simulated expansion state. The cardiac phase can be determined as described in the previous example. In this example, the registration of the vessel can be performed based on the detected location of the balloon in the images in the live sequence. For example, the balloon can be detected in the vessel and registered to the location within the vessel in the volumetric image data 180. As mentioned above, the balloon is visible in the live sequence of images due to the presence of contrast agent within it. Alternatively, the registration of the vessel can be performed based on the detected location of the guidewire within the vessel in the images in the live sequence. In this case, the guidewire can be detected in the vessel and registered to the location within the vessel in the volumetric image data 180. The balloon is typically positioned in the blood vessel by translating it along the guidewire, and the guidewire is visible in the live sequence of images due to its non-transmissive linearity.

[0098] Typically, the registration operation performed in this example can be rigid and / or flexible. In one example, the registration operation can be performed according to the techniques disclosed in document WO2012 / 107857 A1. The operation based on the information 160, 170 output from the registered angiogenesis can, for example, include displaying a first graphical representation and a second graphical representation of the vessels. Additionally or alternatively, it may include a value of a balloon output metric 170 using spatial alignment, which indicates the difference between the shape 140 of the balloon in the simulated inflated state and the shape 150 of the balloon 130 represented in the projected image data 120, as described above.

[0099] In another example, the operation of outputting information 160, 170 for comparing the expansion state of the balloon 130 represented in the projected image data 120 with the simulated expansion state includes:

[0100] Register the blood vessels representing the cardiac phase in volumetric image data 180 to the blood vessels in the current image of the live sequence; and

[0101] Output information 160 and 170 is generated based on the registered blood vessels.

[0102] In this example, the registration operation has the effect of spatially aligning the balloon in the volumetric image data 180 with the balloon in the current image. In this example, the balloon can still move in the current image; however, the balloon in the simulated expansion state also moves accordingly. Therefore, it also reduces the influence of cardiac motion on the output, thereby helping to provide a clearer comparison between the balloon's expansion state represented in the projected image data and the simulated expansion state. As in the previous example, the registration operation can be rigid and / or flexible. The registration operation can be performed according to the techniques disclosed in document WO2012 / 107857 A1. The operation based on the registered angiogenesis output information 160, 170 can also include displaying a first graphical representation and a second graphical representation of the blood vessels. Additionally or alternatively, it can include using the value of a spatially aligned balloon output metric 170, which indicates the difference between the shape 140 of the balloon in the simulated expansion state and the shape 150 of the balloon 130 represented in the projected image data 120, as described above.

[0103] In one example, one or more processors 110 are configured to store a second graphic representation 150 of balloon 130 generated for a current image in a live sequence. In this example, the operation of outputting the second graphic representation 150 of balloon 130 includes: overlapping the stored second graphic representation of balloon 130 with a second graphic representation 150 of balloon 130 generated for a subsequent current image in the live sequence.

[0104] In this example, superimposing the stored second graphic representation of balloon 130 with a second graphic representation 150 of balloon 130 generated for subsequent current images in the live sequence allows for comparison of changes in the actual expansion state of the balloon over time. The stored second graphic representation of balloon 130 can represent its expansion state at any point in time. In one example, the stored second graphic representation of balloon 130 represents its maximum expansion state. As mentioned above, during angioplasty procedures, the physician can inflate and deflate the balloon multiple times, each time inflating it to the same or increased expansion state. Here, it may be useful to return to an earlier maximum expansion state of a reference balloon.

[0105] In one example, the operations that simulate the shape of a virtual balloon expanding in a blood vessel include:

[0106] Analyze the projected image data 120 to identify the type of balloon in the live sequence of images;

[0107] Determine one or more balloon parameters for the type of balloon in the live sequence of the images; and

[0108] The shape of the expanded virtual balloon in the blood vessel is simulated using one or more balloon parameters.

[0109] In this example, the balloon type is determined based on projected image data, and the corresponding balloon parameters are used to simulate the shape of a virtual balloon expanding in a blood vessel. Balloon parameters can be extracted from a database based on the identified balloon type. This example saves time by automatically determining the balloon parameters, as it eliminates the need for manually providing them. Image processing techniques, such as feature detection, can be used to determine the balloon type based on the projected image data. For example, machine learning techniques such as neural networks can also be used to identify the balloon type. As mentioned above, the balloon may include one or more radiopaque markers to enhance its visibility. These markers can also be used to detect the balloon's location and determine its type.

[0110] It should be noted that system 100 may also include one or more of the following: a projection imaging system for providing projection image data 120, such as, for example Figure 1 The illustrated projection X-ray imaging system 230; display, such as Figure 1 The illustrated display 240 is used to display output information 160, 170, other outputs generated by one or more processors 110, etc.; a balloon, for example including Figure 1 The illustrated balloon 130 includes a balloon catheter 250; a hospital bed 260; and a user input device configured to receive user input related to operations performed by one or more processors 110. Figure 1 (Not shown in the image), such as keyboard, mouse, touch screen, etc.

[0111] In one example, a computer-implemented method for providing feedback during balloon angioplasty is provided. The method includes:

[0112] S110 receives projection image data 120 representing the balloon 130 in the blood vessel;

[0113] Based on the shape 140 of the balloon in a simulated expansion state in the blood vessel, and based on the shape 150 of the balloon 130 represented in the projection image data 120, information 160, 170 for comparing the expansion state of the balloon 130 represented in the projection image data 120 with the simulated expansion state is output in S120.

[0114] In one example, a computer program product is provided. The computer program product includes instructions that, when executed by one or more processors, cause the one or more processors to perform a method for providing feedback during balloon angioplasty. The method includes:

[0115] S110 receives projection image data 120 of the balloon 130 in the blood vessel.

[0116] Based on the shape 140 of the balloon in a simulated expansion state in the blood vessel, and based on the shape 150 of the balloon 130 represented in the projection image data 120, information 160, 170 for comparing the expansion state of the balloon 130 represented in the projection image data 120 with the simulated expansion state is output in S120.

[0117] The examples described above should be understood as illustrative of this disclosure, not restrictive. Further examples are also contemplated. For example, the examples described with respect to the system may also be provided in a corresponding manner by a computer-implemented method or by a computer program product or by a computer-readable storage medium. It should be understood that features described with respect to any one example may be used alone or in combination with other described features, and may be used in combination with one or more features of another example, or in combination with other examples. Furthermore, equivalents and modifications not described above may be employed without departing from the scope of the invention as defined in the appended claims. In the claims, the word "comprising" does not exclude other elements or operations, and the words "a" or "an" do not exclude a plurality. Although specific features are recited in dissimilar dependent claims, this does not indicate that combinations of these features cannot be advantageously used. Any reference numerals in the claims should not be construed as limiting their scope.

Claims

1. A system (100) for providing feedback during balloon angioplasty, the system comprising one or more processors (110) configured to: Receive (S110) projection image data (120) representing the balloon (130) in the blood vessel; Based on the shape (140) of the balloon in the simulated expansion state in the blood vessel, and based on the shape (150) of the balloon (130) represented in the projection image data (120), information (160, 170) is output (S120) for comparing the expansion state of the balloon (130) represented in the projection image data (120) with the simulated expansion state. in, The output (S120) of the information (160, 170) includes the value of an output metric (170) that represents the difference between the shape (140) of the balloon in the simulated expansion state and the shape (150) of the balloon (130) represented in the projected image data (120).

2. The system according to claim 1, wherein, The one or more processors (110) are also configured to: Receive volumetric image data (180) representing the blood vessel; and The volumetric image data (180) is used to simulate the expansion of a virtual balloon (130) in the blood vessel. V The shape of the balloon is provided to provide the shape (140) of the balloon in the simulated expansion state.

3. The system according to claim 1 or 2, wherein, The shape (140) of the balloon in the simulated expansion state in the blood vessel represents the shape of the balloon in the simulated expansion state within a virtual stent in the blood vessel.

4. The system according to claim 2, wherein, A virtual balloon (130) simulating the expansion of the blood vessel V The shape of the balloon (140) to provide the shape of the balloon in the simulated expansion state includes: The volumetric image data (180) is used to simulate the rupture of calcium deposits (190) within the blood vessel; and The shape (140) of the balloon in the simulated expansion state (190) is determined based on the simulated rupture of the calcium deposits.

5. The system according to any one of claims 2-4, wherein, A virtual balloon (130) simulating the expansion of the blood vessel V The shapes include: The volumetric image data (180) is analyzed to identify i) the wall (210) of the blood vessel and ii) one or more plaque components (190, 220) within the blood vessel. The mechanical parameters are assigned to i) the wall (210) of the blood vessel, and ii) each of the one or more plaque components (190, 220) within the blood vessel; and Using the assigned mechanical parameters, the dilated virtual balloon (130) in the blood vessel is determined based on i) the identified wall (210) of the blood vessel and ii) the one or more plaque components (190, 220) within the blood vessel. V The shape described above.

6. The system according to any of the preceding claims, wherein, The output (S120) of information (160, 170) for comparing the expansion state of the balloon (130) represented in the projected image data (120) with the simulated expansion state further includes: Output a first graphical representation (140) of the balloon, wherein the balloon is in the simulated inflated state; and Output a second graphic representation (150) of the balloon (130), wherein the balloon is in the expanded state represented in the projected image data (120).

7. The system according to claim 6, wherein, The one or more processors (110) are also configured to output one or more additional graphical representations of the balloon, wherein the balloon is in one or more additional simulated inflated states.

8. The system according to any one of claims 6-7 when dependent on claim 4, wherein, The first graphic representation (140) of the balloon also represents the blood vessel, and wherein the first graphic representation (140) includes the distinction between the wall (210) of the blood vessel and at least one of the one or more plaque components (190, 220).

9. The system according to any one of claims 6-8 when dependent on claim 3, wherein, The first graphic representation (140) includes the balloon (130) VP The virtual projection of the balloon is a virtual projection of the balloon (130) simulated using the volumetric image data (180). V The shape of the balloon (130) is generated by projecting the shape of the first graphic representation (140), thereby making the balloon (130) in the first graphic representation (140) appear as a projection. VP ( ) is represented from the same perspective (α1) as the balloon (130) in the second graphic representation (150).

10. The system according to any of the preceding claims, wherein, The projected image data (120) is acquired from multiple perspectives relative to the balloon, and the shape (150) of the balloon (130) represented in the projected image data (120) is established using the projected image data acquired from the multiple perspectives.

11. The system according to any one of claims 3-10, wherein, The one or more processors (110) are also configured to: The recommended viewing angle (α1) for acquiring the projected image data (120) is determined based on the volumetric image data (180); and Output the value of the recommended perspective (α1).

12. The system according to any of the preceding claims, wherein, The one or more processors (110) are also configured to: Outputs an indication of the recommended type of stent for stent implantation in the said blood vessel; and / or Outputs an indication of recommended values ​​for the size of the stent used for stent implantation in the said blood vessel.

13. The system according to any of the preceding claims, wherein, The projected image data (120) includes a live sequence of images representing the balloon (130) in the blood vessel, and wherein the output is performed for the current image in the live sequence (S120), and the output is repeated for subsequent current images in the live sequence (S120).

14. The system according to claim 13 when dependent on claim 3, wherein, The volumetric image data (180) represents the blood vessels at the cardiac phase; and The output (S120) information (160, 170) for comparing the expansion state of the balloon (130) represented in the projected image data (120) with the simulated expansion state is selectively executed for the current image from the live sequence, the current image representing the blood vessel at the cardiac phase represented in the volumetric image data (180); or The output (S120) of information (160, 170) for comparing the expansion state of the balloon (130) represented in the projected image data (120) with the simulated expansion state includes: Register the blood vessels at one or more different cardiac phases in the current image of the live sequence to the blood vessels at the cardiac phases represented in the volumetric image data (180); and The output information (160, 170) is generated based on the registered blood vessels. or The output (S120) of information (160, 170) for comparing the expansion state of the balloon (130) represented in the projected image data (120) with the simulated expansion state includes: Register the blood vessel at the cardiac phase represented in the volumetric image data (180) to the blood vessel in the current image of the live sequence; and The output information (160, 170) is generated based on the registered blood vessels.

15. The system according to claim 13 or 14 when dependent on claim 3, wherein, The shape of the virtual balloon simulating the expansion in the blood vessel includes: Analyze the projected image data (120) to identify the type of balloon in the live sequence of the images; Determine one or more balloon parameters of the type of balloon in the live sequence of the images; and The shape of the virtual balloon simulating the expansion in the blood vessel is achieved using one or more balloon parameters.

Images