Long-range angiography method and system

Abstract

The embodiment of the invention discloses a long-range blood vessel imaging method and system.The method is applied to C-shaped arm imaging equipment, the C-shaped arm imaging equipment comprises a C-shaped arm, and a ray emitter and a ray detector are arranged at the two ends of the C-shaped arm respectively; the method comprises the following steps: injecting a contrast agent into a blood vessel of a target object; projection data are obtained in a spiral scanning mode through a ray emitter and a ray detector at the two ends of the C-shaped arm; and generating an angiography image based on the projection data.

Description

Technical Field

[0001] The present specification relates to the field of medical technology, and in particular to a long-range vascular imaging method and system. Background Art

[0002] Digital Subtraction Angiography (DSA) is a medical imaging technology that can be used to evaluate and diagnose lesions or abnormalities in the vascular system. DSA uses the principle of X-ray imaging to inject contrast agents (e.g., iodide) into the patient's body and then use X-ray equipment to continuously collect images. The collected images can be used to detect and diagnose various vascular diseases, such as arterial stenosis, thrombosis, aneurysms, etc., to help doctors better determine the location, severity and blood flow of lesions to guide subsequent treatment plans.

[0003] Therefore, some embodiments of the present specification provide a vascular imaging method and system. Summary of the invention

[0004] One of the embodiments of the present specification provides a vascular imaging method, which is applied to a C-arm imaging device, wherein a ray emitter and a ray detector are respectively provided at both ends of the C-arm; the vascular imaging method comprises: injecting a contrast agent into the blood vessels of a target object; acquiring projection data by spiral scanning through the ray emitters and ray detectors at both ends of the C-arm; and generating a vascular angiography image based on the projection data.

[0005] In some embodiments, the projection data is acquired by spiral scanning through the ray emitters and ray detectors at both ends of the C-arm, including: moving the C-arm along a first direction while controlling the ray emitter to rotate around the first direction, receiving the rays emitted by the ray emitter through the ray detector, and acquiring the projection data.

[0006] In some embodiments, the projection data is acquired by spiral scanning using the ray emitters and ray detectors at both ends of the C-arm, including: moving the C-arm from a scanning starting point along a first direction, controlling the ray emitter to rotate around the first direction and controlling the ray emitter to emit rays, receiving the rays emitted by the ray emitter through the ray detector, and acquiring first projection data; controlling the ray emitter to stop emitting rays, and returning the C-arm to the scanning starting point; moving the C-arm from the scanning starting point along a second direction, controlling the ray emitter to rotate around the second direction and controlling the ray emitter to emit rays, receiving the rays emitted by the ray emitter through the ray detector, and acquiring second projection data; wherein the first direction is opposite to the second direction; and determining the projection data based on the first projection data and the second projection data.

[0007] In some embodiments, the projection data is acquired by spiral scanning using the ray emitter and the ray detector at both ends of the C-arm, including: moving the C-arm along a first direction, while controlling the ray emitter to perform a first rotation around the first direction and controlling the ray emitter to emit rays, receiving the rays emitted by the ray emitter through the ray detector, and acquiring first projection data; when the first rotation reaches a preset angle, stopping the first rotation; moving the C-arm along the first direction, while controlling the ray emitter to perform a second rotation around the first direction and controlling the ray emitter to emit rays, receiving the rays emitted by the ray emitter through the ray detector, and acquiring second projection data; wherein the rotation direction of the second rotation is opposite to the rotation direction of the first rotation; determining the projection data based on the first projection data and the second projection data.

[0008] In some embodiments, the C-arm is connected to a frame, and the C-arm is driven to move by the frame. The rotation of the C-arm is achieved by at least one of the following methods: the connection between the frame and the C-arm remains unchanged, and the C-arm rotates relative to the frame; the connection is relatively stationary with the C-arm, and the frame drives the C-arm to rotate; and the connection is equipped with a slide rail, and the C-arm slides relative to the frame along the slide rail.

[0009] In some embodiments, the connection point between the C-arm and the frame is the center position of the C-arm. Alternatively, the connection point between the C-arm and the frame deviates from the center position of the C-arm, and the ray transmitter and the ray receiver can rotate relative to the C-arm.

[0010] In some embodiments, the injection of contrast agent into the target object's blood vessels is performed simultaneously with or in an interleaved manner with the spiral scanning.

[0011] In some embodiments, generating an angiography image based on the projection data includes performing fast reconstruction based on the projection data to obtain a reconstructed image; performing blood vessel segmentation on the reconstructed image to generate the angiography image; or obtaining auxiliary projection data; generating a two-dimensional image sequence based on the projection data and the auxiliary projection data; and generating the angiography image based on the two-dimensional image sequence.

[0012] One of the embodiments of the present specification provides a vascular imaging system, which includes a C-arm imaging device, which includes a C-arm, and a ray emitter and a ray detector are respectively provided at both ends of the C-arm; the vascular imaging system includes: a contrast agent injection module, which is used to inject contrast agent into the blood vessels of the target object; a scanning module, which is used to acquire projection data in a spiral scanning manner through the ray emitter and the ray detector at both ends of the C-arm; and an image generation module, which is used to generate a vascular angiography image based on the projection data. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0014] Figure 1 is a schematic diagram of an application scenario of an exemplary vascular imaging system according to some embodiments of this specification;

[0015] Figure 2 is an exemplary flow chart of a vascular imaging method according to some embodiments of the present specification;

[0016] Figure 3 is another exemplary flow chart of a vascular imaging method according to some embodiments of the present specification;

[0017] Figure 4 is another exemplary flow chart of a vascular imaging method according to some embodiments of the present specification;

[0018] Figure 5 is a block diagram of an exemplary vascular imaging system according to some embodiments of the present specification;

[0019] Figure 6A-6E is an exemplary schematic diagram of a vascular imaging method according to some embodiments of the present specification. DETAILED DESCRIPTION

[0020] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0021] It should be understood that the "system", "device", "unit" and / or "module" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0022] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0023] Flowcharts are used in this specification to illustrate the operations performed by the system according to the embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Instead, the steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0024] Three-dimensional digital subtraction angiography (3D-DSA) is an advanced digital angiography technology that combines traditional digital subtraction angiography (DSA) with three-dimensional reconstruction technology. 3D-DSA continuously acquires multiple 2D-DSA images and uses computer reconstruction algorithms to convert these images into a three-dimensional vascular model. Compared with traditional 2D-DSA, 3D-DSA can provide more comprehensive and intuitive vascular structure information. With 3D-DSA, doctors can rotate, scale and move the vascular model to observe the vascular system from all angles and perspectives. This helps doctors better evaluate the location, shape, size and distribution of vascular lesions, and then make accurate diagnoses and formulate treatment plans.

[0025] CT angiography (CTA) is widely used in the diagnosis of vascular diseases due to its advantages of large range, rapid scanning, non-invasiveness and easy operation, and provides an important diagnostic basis for vascular variations and vascular diseases. By intravenous injection of contrast agent, CT scanning can reconstruct 3D images of blood vessels in the long axial range, assisting doctors in diagnosing head and neck vascular diseases, cardiovascular diseases and peripheral vascular diseases, and is mainly used in preoperative testing. However, intravenous injection brings non-specific problems to CTA; CTA is a medical imaging diagnostic device. In the diagnosis and treatment process, CTA examinations take a lot of time for acute patients. Therefore, it is urgent to achieve the acquisition of vascular images, diagnosis and treatment in a one-time manner in the treatment place (for example, the catheterization room).

[0026] In practical applications, such as the diagnosis and treatment process of stroke, doctors hope to see a long-range 3D vascular image from the aortic arch to the top of the skull. C-arm X-ray imaging equipment, such as cone beam computed tomography (CBCT), has the functions of two-dimensional angiography and three-dimensional angiography through the method of digital subtraction angiography (DSA). DSA generally uses arterial injection of contrast agent. Taking intracranial angiography as an example, 3D-DSA completes three-dimensional vascular imaging of the hemisphere of the brain with an axial area of ​​about 18 cm after internal carotid artery catheterization. It is used for intraoperative diagnosis of diseases such as aneurysms or vascular stenosis, and postoperative evaluation of the effect of interventional treatment. DSA equipment is the gold standard for the diagnosis of many vascular diseases and is a key imaging device in interventional treatment. However, the total coverage of the projection image of the current DSA equipment is small, and the reconstructed 3D vascular range is small. Multiple intracranial angiography is required for whole-brain vascular imaging, and 3D vascular imaging from the aortic arch to the top of the skull cannot be completed directly.

[0027] The spiral scanning method using a C-arm X-ray imaging system can achieve long-axial range soft tissue imaging. However, the soft tissue contrast resolution of CBCT is not high, the scanning time is long, and its long-range tomographic imaging lacks clinical application value.

[0028] The contrast agent is injected into the artery by a high-pressure syringe and diffuses along the artery with the blood. The continuously injected contrast agent gradually fills the blood vessels and then enters the capillaries and veins. The contrast agent validity period of arterial vascular imaging is limited, and the scanning time of the imaging equipment is limited. The traditional long-axial range spiral scanning scheme does not consider key factors such as the amount of contrast agent used / injection rate, contrast agent diffusion time, etc., and cannot be applied to long-range vascular imaging.

[0029] In view of this, some embodiments of the present specification provide a method and system for intraoperative long-axial range vascular imaging. On a C-arm X-ray imaging system, vascular contrast agent is injected, X-ray projection is performed using a spiral scanning method, and three-dimensional vascular images in the long-axial range are quickly and accurately reconstructed based on the projection data.

[0030] Figure 1 is a schematic diagram of an application scenario of an exemplary vascular imaging system according to some embodiments of the present specification.

[0031] like Figure 1 As shown, the application scenario 100 of the vascular imaging system includes a C-arm imaging device 110 , a processing device 120 , a terminal device 130 , a storage device 140 and a network 150 .

[0032] The C-arm imaging device 110 can be used to scan a target object in a detection area or a scanning area to obtain scanning data of the target object.

[0033] In some embodiments, the C-arm imaging device 110 includes a C-arm 111 , a radiation emitter 112 and a radiation detector 113 respectively disposed at two ends of the C-arm 111 , a frame 114 , and a high-pressure injector 115 .

[0034] In some embodiments, the C-arm is connected to the frame, and the frame can drive the C-arm to move. The connection method may include mechanical joints, electric control, magnetic adsorption, fixed connection, etc., which are not limited in this specification. The above description of the C-arm imaging device is for illustrative purposes only and is not intended to limit the scope of this specification.

[0035] The processing device 120 can be used to process data and / or information obtained from the C-arm imaging device 110, the terminal device 130, the storage device 140 and / or other components of the application scenario 100 of the vascular imaging system, and analyze and / or process the data and / or information. For example, the processing device 120 obtains projection data from the C-arm imaging device 110; based on the projection data, generates a vascular angiography image.

[0036] In some embodiments, the processing device 120 is a single server or a server group. The server group can be centralized or distributed. In some embodiments, the processing device 120 can be local or remote. For example, the processing device 120 can access information and / or data from the C-arm imaging device 110, the terminal device 130 and / or the storage device 140 through the network 150. For another example, the processing device 120 can be directly connected to the C-arm imaging device 110, the terminal device 130 and / or the storage device 140 to access information and / or data. In some embodiments, the processing device 120 is implemented on a cloud platform. For example, the cloud platform includes a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, a cloud-to-cloud cloud, a multi-cloud, etc. or any combination thereof.

[0037] In some embodiments, the processing device 120 and the C-arm imaging device 110 may be integrated into one. In some embodiments, the processing device 120 and the C-arm imaging device 110 may be directly or indirectly connected to jointly implement the methods and / or functions described in this specification.

[0038] The terminal device 130 can communicate and / or connect with the C-arm imaging device 110, the processing device 120 and / or the storage device 140. In some embodiments, the interaction with the user can be achieved through the terminal device 130. In some embodiments, the terminal device 130 may include a mobile device 131, a tablet computer 132, a laptop computer 133, etc. or any combination thereof. In some embodiments, the terminal device 130 (or all or part of its functions) may be integrated in the processing device 120.

[0039] The storage device 140 may store data, instructions, and / or any other information. In some embodiments, the storage device 140 may store data (e.g., projection data, etc.) acquired from the C-arm imaging device 110, the processing device 120, the terminal device 130, and / or the like. In some embodiments, the storage device 140 may store data and / or instructions that the processing device 120 uses to execute or use to complete the exemplary methods described in this specification.

[0040] In some embodiments, the storage device 140 may include one or more storage components, each of which may be an independent device or a part of another device. In some embodiments, the storage device 140 may include a random access memory (RAM), a read-only memory (ROM), a mass storage device, a removable memory, a volatile read-write memory, etc. or any combination thereof. In some embodiments, the storage device 140 may be implemented on a cloud platform. In some embodiments, the storage device 140 may be a part of the C-arm imaging device 110, the processing device 120 and / or the terminal device 130.

[0041] The network 150 may include any suitable network capable of facilitating information and / or data exchange. In some embodiments, at least one component of the application scenario 100 of the vascular imaging system (e.g., the C-arm imaging device 110, the processing device 120, the terminal device 130, the storage device 140) may exchange information and / or data with at least one other component in the application scenario 100 of the vascular imaging system via the network 150. For example, the processing device 120 may obtain projection data, etc. from the C-arm imaging device 110 via the network 150.

[0042] It should be noted that the above description of the application scenario 100 of the vascular imaging system is provided for illustrative purposes only and is not intended to limit the scope of this specification. For those of ordinary skill in the art, various modifications or variations can be made based on the description of this specification. For example, the application scenario 100 of the vascular imaging system can implement similar or different functions on other devices. However, these changes and modifications will not deviate from the scope of this specification.

[0043] Figure 2 FIG. 2 is an exemplary flow chart of an image annotation method 200 according to some embodiments of the present specification. Figure 2 As shown, the method 200 includes the following steps.

[0044] Step 210 , injecting contrast agent into a blood vessel of the target object. In some embodiments, step 210 may be performed by the processing device 120 or the contrast agent injection module 510 .

[0045] The target object refers to the object of detection, for example, the target object may include a patient visiting a doctor, a physical examination guest, a radiotherapy patient, etc. In some embodiments, the target object may include a specific part of the body, such as the head, chest, abdomen, arms, legs, etc. or any combination thereof.

[0046] A contrast agent is a substance used for medical examination and diagnosis, and is usually injected, taken orally, or other ways into the human body. By injecting contrast agents into blood vessels, the contrast of blood vessels in imaging such as X-rays and CT scans can be improved. In some embodiments, the contrast agent includes sodium iodide or iodate. In some embodiments, the contrast agent injection module 510 controls a high-pressure injector to inject contrast agents into the blood vessels of the target object.

[0047] The contrast agent can be injected through a vein or an artery. In some embodiments, the contrast agent injection module 510 can determine the injection position of the contrast agent into the blood vessels of the target object according to the needs. For example, in lower extremity vascular intervention surgery, the contrast agent is injected into the tibial vein or the femoral vein. For another example, when evaluating the condition of the entire vascular system, the contrast agent is injected intravenously, and the contrast agent injected intravenously will be delivered to the entire vascular system, including arteries and veins, thereby providing a comprehensive vascular imaging, not just arterial blood vessels. For another example, in cerebral vascular imaging, the contrast agent is injected at the aortic arch. This is because the contrast agent can quickly reach the brain from the aortic arch; if injected through a vein (for example, a vein in the arm), the contrast agent will flow with the blood to the left heart, then enter the lungs, and then return to the heart, and finally be delivered to the brain, which takes a long time; and intravenous injection imaging usually does not only show arterial blood vessels, but displays images of multiple blood vessels.

[0048] In some embodiments, the contrast agent injection module 510 can determine the speed, concentration, injection duration, injection start / end time, injection interval, etc. of injecting contrast agent into the target object's blood vessels as required to coordinate the scanning process. For example, the contrast agent injection module 510 can start injecting contrast agent into the target object's blood vessels 2 seconds before the start of the scanning process. For another example, the contrast agent injection module 510 can stop injecting contrast agent into the target object's blood vessels 2 seconds before the end of the scanning process. For more examples of injecting contrast agent into the target object's blood vessels, please refer to step 220 and Figure 3 Description.

[0049] Compared with the spiral scanning cone beam computed tomography (CBCT) method, the vascular imaging method proposed in some embodiments of the present specification introduces angiography technology, which can improve vascular contrast and achieve clear imaging of blood vessels at all levels. Compared with the existing three-dimensional digital subtraction angiography (3D-DSA) method, it can expand the axial vascular imaging range. For example, in cerebral vascular imaging, by injecting contrast agent at the aortic arch, a single imaging can be used to obtain vascular imaging of the long axial 3D range from the aortic arch to the top of the skull, which is helpful for surgical evaluation planning and navigation, and reduces the relevant operation time, and reduces the risk of complications caused by catheter invasion of intracranial blood vessels. Compared with the CT angiography (CTA) imaging method, it can avoid the low specificity of intravenous injection, have higher-definition vascular 3D imaging results, and eliminate the need for preoperative CTA examinations, which can greatly reduce the preoperative examination time of acute stroke patients and improve the success rate of rescue.

[0050] Step 220 , the projection data is acquired by spiral scanning through the ray emitters and ray detectors at both ends of the C-arm. In some embodiments, step 220 may be performed by the processing device 120 or the scanning module 520 .

[0051] In some embodiments, the scanning module 520 can perform spiral scanning during the diffusion phase or the filling phase. The diffusion phase refers to the time period during which the contrast agent gradually diffuses or spreads after being injected into a blood vessel. The filling phase refers to the time period during which the contrast agent fully diffuses to the target blood vessel after being injected into a blood vessel, making the target blood vessel clearly visualized.

[0052] Helical scanning refers to scanning while performing a spiral motion. Helical motion is a motion that combines rotation and advancement. By combining rotation and advancement, the object will form a spiral motion. In a spiral scan, the radiation emitter and / or radiation detector moves along one direction (for example, the extension direction of the length of the scanning bed) while rotating around the target object. The spiral scanning method can obtain continuous volume data of the scan area in a single scan process.

[0053] In some embodiments, the spiral scan is implemented based on a C-arm. For example, the scanning module 520 drives the C-arm to move along the length of the scanning bed through the frame. For another example, the scanning module 520 controls the C-arm to rotate around the target object or slide along the arc of the C-arm to rotate the ray emitter and the ray detector at both ends of the C-arm.

[0054] In some embodiments, the connection between the C-arm and the frame is the center of the C-arm. Figure 1 The scanning module 520 makes the center of the C-arm in the moving direction, drives the C-arm to move along the moving direction through the frame, and controls the C-arm to rotate around the moving direction to rotate the ray emitters and ray detectors at both ends.

[0055] Projection data refers to data obtained at different angles or directions, reflecting the absorption and scattering information of the target object's tissue to the radiation. For example, in a brain scan, data reflecting the absorption and scattering information of the brain tissue to the radiation is obtained at multiple angles such as above, below, side and / or oblique angles.

[0056] In some embodiments, during the spiral scanning process, the scanning module 520 causes the ray emitter at one end of the C-arm to emit rays, and causes the ray detector at the other end of the C-arm to receive the rays, and obtains projection data based on the measurement of the received rays by the ray detector.

[0057] In some embodiments, the scanning module 520 can move the C-arm along a first direction while controlling the ray emitter to rotate around the first direction, and receive the rays emitted by the ray emitter through the ray detector to obtain projection data.

[0058] The first direction refers to one of the directions along the length of the scanning bed. For example, the first direction is Fig. 6A One of the positive z-axis direction or the negative z-axis direction.

[0059] The rotation of the radiation emitter around the first direction as the axis may be a clockwise circular motion or a counterclockwise circular motion.

[0060] For example, Fig. 6A As shown, in head and neck vascular imaging, the scanning starting point is the aortic arch, and the scanning module 520 moves the C-arm along the direction from the feet to the head, while controlling the ray emitter to perform counterclockwise circular motion around the direction from the feet to the head as the axis, so that the ray generator at one end of the C-arm performs spiral scanning motion; the ray detector receives the rays emitted by the ray emitter at several positions on the spiral scanning trajectory to obtain projection data.

[0061] In some embodiments, contrast agent injection into the target subject's blood vessels is performed simultaneously with or interleaved with the helical scan.

[0062] Simultaneous means that the injection of contrast agent into the blood vessel and the spiral scan start and / or end at the same time. For example, when the ray emitter at one end of the C-arm starts to rotate and emits radiation, the injection of contrast agent into the blood vessel of the target object starts. For another example, when the ray emitter stops rotating and stops emitting radiation, the injection of contrast agent into the blood vessel of the target object stops.

[0063] Cross-cutting is performed so that contrast agent injection into the blood vessel and spiral scanning start and / or end at different times. For example, contrast agent injection into the blood vessel is performed before spiral scanning starts. For another example, contrast agent injection into the blood vessel is stopped before spiral scanning stops.

[0064] At the moment of starting to inject contrast agent, the contrast agent in the blood vessel may not have diffused yet, the visibility of the blood vessel will not be improved immediately, and the quality of the scanned image will not be improved at this time. Therefore, the scanning module 520 can delay the spiral scanning, that is, wait until the contrast agent reaches a full state before starting the spiral scanning.

[0065] For example, Figure 6B As shown, contrast agent is injected into the blood vessel at 0 seconds, and spiral scanning starts at 2.4 seconds; contrast agent is injected into the blood vessel again at 9.6 seconds, and spiral scanning starts again at 12 seconds. Curve 610 is the injection concentration curve of contrast agent; stage ①, i.e., 2.4 seconds to 9.6 seconds, is the contrast agent filling stage; stage ②, i.e., 9.6 seconds to 12 seconds, is the contrast agent disappearing stage; stage ③, i.e., the period after 12 seconds, is the contrast agent filling stage, and the contrast agent reaches the filling state again.

[0066] During the period when contrast agent injection is stopped, the contrast agent in the blood vessel may not have disappeared, and the filling state may last for a while. Therefore, the scanning module 520 can continue the spiral scanning, that is, wait until the contrast agent is no longer in the filling state before stopping the spiral scanning.

[0067] For example, Figure 6B As shown, the injection of contrast agent into the blood vessel was stopped at 7.2 seconds, and the spiral scanning was stopped at 9.6 seconds; the injection of contrast agent into the blood vessel was stopped again at 16.8 seconds, and the spiral scanning was stopped again at about 18 seconds.

[0068] Cross-vascular injection of contrast agent and spiral scanning helps to accurately control the scanning process during the optimal period of contrast agent filling, obtain the best image quality in the shortest time, improve scanning efficiency and quality, reduce the time patients need to maintain a specific position or be exposed to radiation, thereby improving patient comfort and safety.

[0069] Step 230 , generating an angiography image based on the projection data. In some embodiments, step 230 may be performed by the processing device 120 or the image generation module 530 .

[0070] Angiographic images refer to images that present the structure, position, morphology, etc. of a target object's blood vessels. Angiographic images can assist in the diagnosis and assessment of vascular diseases, abnormal dilatation, stenosis, embolism, etc. In some embodiments, angiographic images can be presented in a three-dimensional manner.

[0071] In some embodiments, the image generation module 530 performs rapid reconstruction based on the projection data to obtain a reconstructed image; and performs blood vessel segmentation on the reconstructed image to generate a blood vessel angiography image.

[0072] In some embodiments, the image generation module 530 can use Circular FDK, Helical FDK, Katsevich and other reconstruction algorithms to quickly reconstruct based on the projection data to obtain a reconstructed image. In some embodiments, the image generation module 530 can also use filtering, back-projection and other methods to quickly reconstruct based on the projection data to obtain a reconstructed image.

[0073] In some embodiments, the image generation module 530 performs blood vessel segmentation on the reconstructed image using one or more methods selected from edge detection, morphological operation, region growing, and active contour model. In some embodiments, the image generation module 530 marks the segmented blood vessels in the reconstructed image (e.g., by drawing the contour of the blood vessels in the reconstructed image) to generate angiography images.

[0074] Based on the projection image and combined with precise reconstruction methods, the three-dimensional reconstruction of blood vessels can be completed quickly, enabling real-time viewing of long-range angiography results during surgery.

[0075] The intraoperative long-axial range vascular imaging method can achieve long-axial range vascular imaging during aortic interventional surgery for aortic dissection or thoracic and abdominal aortic aneurysm, and lower limb vascular interventional surgery, which is beneficial for comprehensive observation of vascular lesions.

[0076] By combining angiography and spiral scanning, as well as rapidly reconstructing images, higher-contrast vascular images within the long-axis range can be achieved in a shorter time, efficiently providing an imaging basis for emergency surgery.

[0077] Figure 3 is another exemplary flow chart of a vascular imaging method according to some embodiments of the present specification. In some embodiments, method 300 can be used to implement step 220 in method 200 to obtain projection data in a spiral scanning manner through the ray emitters and ray detectors at both ends of the C-arm. In some embodiments, method 300 can be executed by processing device 120 or scanning module 520.

[0078] like Figure 3 As shown, the method 300 includes the following steps.

[0079] Step 310, the C-arm is moved from the scanning starting point along the first direction, and at the same time, the ray emitter is controlled to rotate around the first direction and to emit rays, and the rays emitted by the ray emitter are received by the ray detector to obtain first projection data.

[0080] For example, Figure 6B As shown, in stage ①, the contrast agent in the blood vessel is in a filled state, and the C-arm starts from the scanning starting point (e.g., the mouth), moves along the first direction (from the foot to the head), and the ray emitter emits rays and rotates counterclockwise around the first direction. The scanning module 520 receives the rays emitted by the ray emitter through the ray detector to obtain the first projection data.

[0081] The scanning starting point refers to the starting position of the spiral scanning process. The scanning starting point can be represented by the position on the surface and / or inside of the target object, the position of the ray emitter and / or the position of the ray detector. For example, the scanning starting point is the mouth or the aortic arch. For another example, the scanning starting point is when the ray emitter is located directly above the midpoint of the scanning bed and / or the ray detector is located directly below the midpoint of the scanning bed.

[0082] In some embodiments, the scanning module 520 selects an endpoint or a non-endpoint (a point other than an endpoint in the scanning area) of the scanning area as the scanning starting point. For example, an endpoint of the scanning area, the center point of the scanning area, the golden section position in the scanning area, etc. are selected as the scanning starting point. In some embodiments, the scanning starting point can be determined based on the scanning requirements. For example, in a single head and neck vascular imaging, an endpoint of the scanning area, that is, the aortic arch, is used as the scanning starting point. For another example, in a secondary head and neck vascular imaging, the center point of the scanning area (approximately at the mouth) is used as the scanning starting point.

[0083] Step 320, controlling the ray emitter to stop emitting rays and returning the C-arm to the scanning starting point.

[0084] For example, Figure 6B As shown, in stage ②, the contrast agent in the blood vessel is in a dissipating state, and the C-arm and the ray generator return to the scanning starting point. During this process, the ray emitter does not emit rays.

[0085] Step 330, move the C-arm from the scanning starting point along the second direction, control the ray emitter to rotate around the second direction and control the ray emitter to emit rays, receive the rays emitted by the ray emitter through the ray detector, and obtain second projection data; wherein the first direction and the second direction are opposite.

[0086] The second direction refers to the direction opposite to the first direction in the length direction of the scanning bed. Fig. 6A In the example, the first direction is the positive direction of the z-axis, and the second direction is the negative direction of the z-axis.

[0087] For example, Figure 6B As shown, in stage ③, the contrast agent in the blood vessel is filled again, and the C-arm starts from the scanning starting point (e.g., the mouth) and moves along the second direction (head to toe direction), while the ray emitter emits rays and rotates clockwise around the second direction. The scanning module 520 receives the rays emitted by the ray emitter through the ray detector to obtain the second projection data.

[0088] It is worth noting that the scanning starting points of the first projection data and the second projection data are the same, so the first projection data and the second projection data can together constitute continuous spiral trajectory projection data.

[0089] The bidirectional spiral scanning trajectory with the non-endpoint as the scanning starting point can avoid the problem of wasted scanning time caused by the inability of the C-arm of the existing C-arm X-ray imaging system to rotate multiple circles continuously, or the problem of dose waste and poor reconstruction effect caused by the non-continuous spiral trajectory. It can make full use of the diffusion time of the contrast agent and ensure the contrast of the key areas.

[0090] In some embodiments, the scanning module 520 obtains the first projection data and the second projection data by other methods. In some embodiments, the scanning module 520 obtains the first projection data by moving the C-arm along the first direction, controlling the ray emitter to make a first rotation around the first direction and controlling the ray emitter to emit rays, and receiving the rays emitted by the ray emitter through the ray detector; when the first rotation reaches a preset angle, the first rotation is stopped; the C-arm is moved along the first direction, controlling the ray emitter to make a second rotation around the first direction and controlling the ray emitter to emit rays, and receiving the rays emitted by the ray emitter through the ray detector, and obtaining the second projection data; wherein the rotation direction of the second rotation is opposite to the rotation direction of the first rotation.

[0091] For example, Fig. 6E As shown, in stage ④, the ray generator emits rays, and the ray generator starts from the scanning starting point, rotates clockwise / counterclockwise to make a circular motion, and moves in the positive direction of the z-axis at the same time; the ray emitted by the ray emitter is received by the ray detector to obtain the first projection data. The high-pressure injector is controlled to inject the contrast agent before the start of stage ④, and stops injecting the contrast agent before the end of stage ④.

[0092] When the ray generator rotates to a preset angle, it stops emitting rays, and stops circular motion and positive motion in the z-axis direction. The preset angle may be the maximum angle at which the C-arm can rotate, such as 200 degrees, 400 degrees, etc. The preset angle may also be a preferred angle determined based on experience, such as 180 degrees, 360 degrees, etc.

[0093] In stage ⑤, the ray generator emits rays. Starting from the end point of the rotation in stage ④, the ray generator makes a circular motion in the opposite direction of stage ④, while continuing to move in the positive direction of the z-axis. The ray detector receives the rays emitted by the ray emitter to obtain the second projection data. The high-pressure injector is controlled to inject the contrast agent before the start of stage ⑤, and stops injecting the contrast agent before the end of stage ⑤.

[0094] It is worth noting that the scanning end point of stage ④ is the same as the scanning start point of stage ⑤. Therefore, the first projection data obtained in stage ④ and the second projection data obtained in stage ⑤ can also jointly constitute continuous spiral trajectory projection data.

[0095] Step 340: Determine projection data based on the first projection data and the second projection data.

[0096] In some embodiments, the scanning module 520 may obtain the projection data by splicing the first projection data and the second projection data.

[0097] In some embodiments, the scanning module 520 may divide the scanning range into a plurality of sub-ranges, determine a local scanning starting point of each sub-range (eg, the midpoint of the sub-range), and perform a local scanning operation on each sub-range. Figure 6B or Fig. 6E The steps shown in the figure obtain multiple sets of local projection data, each set of local projection data includes local first projection data and local second projection data. The scanning module 520 can obtain projection data by splicing multiple sets of local projection data.

[0098] The existing C-arm has a limited continuous rotation angle, and the C-arm needs to be reset between two or more scans. By pausing contrast agent injection between scans, the amount of contrast agent used can be reduced; by injecting contrast agent in advance before each scan, the scanning period and the contrast agent filling period can be overlapped, which can maximize the use of contrast agent filling time and obtain long-range continuous spiral scanning contrast images under the condition of limited C-arm rotation angle.

[0099] In some embodiments, the rotation of the C-arm is achieved by relative rotation between the C-arm and the frame. Figure 1 As shown, the frame and the connection remain unchanged, and the C-arm rotates around the first direction.

[0100] It is worth noting that Figure 1 In the embodiment, the C-arm is in the head position, that is, the plane where the C-arm is located is parallel to the first direction. The scanning process of this design is simple to control, but the scanning depth is limited by the radius of the C-arm, that is, the maximum depth of the scanning range is the radius of the C-arm.

[0101] In some embodiments, the rotation of the C-arm is achieved by the frame driving the C-arm to rotate. Figure 6CAs shown, the connection and the C-arm are relatively stationary, and the frame drives the C-arm to rotate. The dotted one-way arrow on the left is the movement trajectory of the frame driving the C-arm to move along the first direction, and the dotted circular arrow is the movement trajectory of the connection rotating around the first direction when the frame drives the C-arm to rotate.

[0102] In some embodiments, the rotation of the C-arm can be achieved by relative sliding between the C-arm and the frame. In some embodiments, a slide rail is installed at the connection between the frame and the C-arm, for example, Fig.6D The C-arm can slide on the slide rail to move relative to the frame. Fig.6D As shown, the C-arm slides on the slide rail 640, and the C-arm moves along the arc of the C-arm, driving the ray generator at one end of the C-arm to make a circular motion around the center line, thereby realizing spiral scanning.

[0103] It is worth noting that Fig.6D The C-arm is in a vertical position, that is, the plane where the C-arm is located is perpendicular to the longitudinal center axis of the target object. The C-arm can move along a first direction driven by the frame to enable the spiral scan to cover a larger axial range (for example, the range of the patient's entire body).

[0104] In some embodiments, the connection between the C-arm and the frame is offset from the center of the C-arm, and the radiation transmitter and the radiation receiver can rotate relative to the C-arm. Figure 6C As shown, the connection is below the center of the C-arm, and the ray transmitter and the ray receiver can rotate relative to the C-arm, and the axis of relative rotation is the line connecting the center of the ray transmitter and the center of the ray receiver.

[0105] It is worth noting that Figure 6C The middle C-arm is in a lateral position, that is, the plane where the C-arm is located forms an angle less than 90 degrees with the first direction. Figure 6C In the embodiment, the connection between the gantry and the C-arm makes a circular motion around the first direction and moves in the first direction. The connection between the gantry and the C-arm is at the side of the scanning bed. The rotation trajectory of the connection between the gantry and the C-arm is as follows: Figure 6C As shown by the dotted circular arrow in the figure, this rotation method allows the C-arm and the frame to bypass the scanning bed and the target object, solving the problem of insufficient depth when the C-arm is in the head position and achieving a longer range of spiral scanning.

[0106] Since the position of the rotation point is not the center of the C-arm when the C-arm rotates, the relative position of the ray emitter and the ray detector will be reversed during the rotation process, for example, Figure 6C The vertical dashed line shown in will be aligned with the first direction ( Figure 6CThe central axis (dashed line) is not on the same plane (do not intersect), and the direction of the projection image will be inconsistent. This phenomenon can be avoided by the relative rotation of the ray emitter and ray receiver with the C-arm to ensure the consistency of the direction of the projection image.

[0107] Figure 4 is another exemplary flow chart of a vascular imaging method according to some embodiments of the present specification.

[0108] In some embodiments, if the angiography image generated in step 230 does not meet the preset conditions and / or clinical needs, the angiography image needs to be regenerated. The preset conditions include that the contrast between the blood vessels and the surrounding tissues in the angiography image is higher than a preset threshold, such as 5%, and the threshold can be manually adjusted when viewing the image; based on the angiography image, the target blood vessels can be segmented, etc. Clinical needs include that the doctor believes that the angiography image has clearly displayed the vascular structure, etc.

[0109] In some embodiments, the image generation module 530 may regenerate the angiography image by the method 400. In some embodiments, the method 400 may be performed by the processing device 120 or the image generation module 530.

[0110] like Figure 4 As shown, method 400 includes the following steps.

[0111] Step 410: Acquire auxiliary projection data.

[0112] Auxiliary projection data refers to the projection data of the target object collected without contrast agent injection. The auxiliary projection data can reflect the preliminary information of the target object, but due to the lack of contrast agent enhancement effect, the contrast of blood vessels is low.

[0113] In some embodiments, the processing device 120 acquires the auxiliary projection data by a method that is the same as and / or similar to step 220 .

[0114] Step 420: Generate a two-dimensional image sequence based on the projection data and the auxiliary projection data.

[0115] In some embodiments, the processing device 120 generates a two-dimensional image sequence by performing digital subtraction on the projection data and the auxiliary projection data.

[0116] Digital subtraction refers to an image processing method that subtracts auxiliary projection data from projection data. Due to the presence of contrast agents, the vascular structure in the projection data becomes more obvious, while the tissues and / or organs surrounding the blood vessels in the projection data are the same or similar to those in the auxiliary projection data. Therefore, through mathematical operations, by subtracting the auxiliary projection data from the projection data, an image showing only the blood vessels filled with contrast agents can be obtained.

[0117] The two-dimensional image sequence is a collection of multiple two-dimensional images, which are two-dimensional vascular subtraction images of the target object at multiple positions and / or angles.

[0118] In some embodiments, the processing device 120 may perform digital subtraction of each projection data from the corresponding auxiliary projection data to obtain a two-dimensional vascular subtraction image corresponding to the projection data, and compose these two-dimensional angiography images into a two-dimensional image sequence.

[0119] Step 430 , generating an angiography image based on the two-dimensional image sequence.

[0120] In some embodiments, the image generation module 530 may generate angiography images based on a two-dimensional image sequence by using a reconstruction algorithm (eg, Circular FDK, Helical FDK, Katsevich, etc.), filtering, back-projection, and other methods.

[0121] Step 230 does not require rescanning to obtain auxiliary projection data, which can reduce the radiation exposure of the target object, reduce the scanning time, shorten the preoperative examination time, and improve the success rate of rescue. Method 400 is used as a backup solution when the angiography image generated by step 230 is of poor quality, and can provide a reliable imaging basis for surgery.

[0122] Figure 5 is a block diagram of an exemplary vascular imaging system according to some embodiments of the present specification.

[0123] like Figure 5 As shown, in some embodiments, the vascular imaging system 500 may include a contrast agent injection module 510 , a scanning module 520 , and an image generation module 530 .

[0124] The contrast agent injection module 510 can be used to inject contrast agent into the blood vessels of the target object. For more information about contrast agent injection, please refer to step 210 and its related description.

[0125] The scanning module 520 can be used to acquire projection data in a spiral scanning manner through the ray emitters and ray detectors at both ends of the C-arm when the contrast agent in the blood vessels of the target object is filled. For more information about the acquisition of projection data, please refer to step 220 and its related description.

[0126] The image generation module 530 may be used to generate an angiography image based on the projection data. For more information about the generation of angiography images, please refer to step 230 and its related description.

[0127] It should be understood that Figure 5The system and its modules shown can be implemented in various ways. For example, by hardware, software, or a combination of software and hardware. The system and its modules of this specification can be implemented not only by hardware circuits such as very large scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, but also by software implemented by, for example, various types of processors, and can also be implemented by a combination of the above hardware circuits and software (e.g., firmware).

[0128] It should be noted that the above description of the system and its modules is only for convenience of description and is not intended to limit the present specification to the embodiments described above. It is understandable that, after understanding the principle of the system, those skilled in the art may arbitrarily combine the modules or form a subsystem to connect with other modules without departing from the principle.

[0129] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this specification. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

[0130] At the same time, this specification uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of this specification can be appropriately combined.

[0131] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this specification, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0132] Similarly, it should be noted that in order to simplify the description disclosed in this specification and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this specification, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the subject matter of this specification are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0133] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0134] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, documents, etc., cited in this specification are hereby incorporated by reference in their entirety. Except for application history documents that are inconsistent with or conflicting with the contents of this specification, documents that limit the broadest scope of the claims of this specification (currently or later attached to this specification) are also excluded. It should be noted that if the descriptions, definitions, and / or use of terms in the materials attached to this specification are inconsistent or conflicting with the contents described in this specification, the descriptions, definitions, and / or use of terms in this specification shall prevail.

[0135] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, as an example and not a limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. A vascular imaging method, the method being applied to a C-arm imaging device, the C-arm imaging device comprising a C-arm, wherein two ends of the C-arm are respectively provided with a ray emitter and a ray detector; the method include: injecting contrast medium into the blood vessels of the target subject; Acquiring projection data by spiral scanning through the ray emitters and ray detectors at both ends of the C-arm; Based on the projection data, an angiographic image is generated.

2. The method according to claim 1, wherein the projection data is acquired by spiral scanning using the ray emitters and ray detectors at both ends of the C-arm. include: The C-arm is moved along a first direction while the ray emitter is controlled to rotate around the first direction, and the ray emitted by the ray emitter is received by the ray detector to acquire the projection data.

3. The method according to claim 2, wherein the projection data is acquired by spiral scanning using the ray emitters and ray detectors at both ends of the C-arm. include: The C-arm is moved along a first direction, and at the same time, the ray emitter is controlled to perform a first rotation around the first direction and to emit rays, and the ray detector receives the rays emitted by the ray emitter to obtain first projection data; When the first rotation reaches a preset angle, stopping the first rotation; The C-arm is moved along a first direction, and at the same time, the ray emitter is controlled to perform a second rotation around the first direction and to emit rays, and the ray detector receives the rays emitted by the ray emitter to obtain second projection data; wherein the rotation direction of the second rotation is opposite to the rotation direction of the first rotation; The projection data is determined based on the first projection data and the second projection data.

4. The method according to claim 1, wherein the projection data is acquired by spiral scanning using the ray emitters and ray detectors at both ends of the C-arm. include: The C-arm is moved from a scanning starting point along a first direction, and at the same time, the ray emitter is controlled to rotate around the first direction and to emit rays, and the ray detector receives the rays emitted by the ray emitter to obtain first projection data; Controlling the ray emitter to stop emitting rays and returning the C-arm to the scanning starting point; The C-arm is moved from the scanning starting point along a second direction, and the ray emitter is controlled to rotate around the second direction and to emit rays, and the ray detector receives the rays emitted by the ray emitter to obtain second projection data; wherein the first direction is opposite to the second direction; The projection data is determined based on the first projection data and the second projection data.

5. The method according to any one of claims 2 to 4, wherein the C-arm is connected to a frame, and the C-arm is driven to move by the frame; the rotation of the C-arm is achieved by at least one of the following methods: The connection between the frame and the C-arm remains unchanged, and the C-arm rotates relative to the frame; The connection part and the C-arm are relatively stationary, and the frame drives the C-arm to rotate; and The connection is provided with a slide rail, and the C-shaped arm slides relative to the frame along the slide rail.

6. According to the method of claim 5, the connection between the C-arm and the frame is the center position of the C-arm; or, the connection between the C-arm and the frame deviates from the center position of the C-arm, and the radiation transmitter and the radiation receiver can rotate relative to the C-arm. 7 . The method according to claim 1 , wherein the injection of contrast agent into the blood vessels of the target object is performed simultaneously with or in an interleaved manner with the spiral scanning.

8. The method according to claim 1, wherein generating an angiographic image based on the projection data, include: Performing rapid reconstruction based on the projection data to obtain a reconstructed image; performing blood vessel segmentation on the reconstructed image to generate the angiography image; Alternatively, obtain auxiliary projection data; generating a two-dimensional image sequence based on the projection data and the auxiliary projection data; Based on the two-dimensional image sequence, the angiography image is generated.

9. A vascular imaging system, comprising a C-arm imaging device, wherein the C-arm imaging device comprises a C-arm, and a ray emitter and a ray detector are respectively arranged at both ends of the C-arm; include: a contrast agent injection module, for injecting contrast agent into a blood vessel of a target subject; A scanning module, used for acquiring projection data in a spiral scanning manner through ray emitters and ray detectors at both ends of the C-arm; An image generation module is used to generate a blood vessel angiography image based on the projection data.

10. The system according to claim 9, wherein the projection data is acquired by spiral scanning through the ray emitters and ray detectors at both ends of the C-arm. include: The C-arm is moved along a first direction while the ray emitter is controlled to rotate around the first direction, and the ray emitted by the ray emitter is received by the ray detector to acquire the projection data.

11. The system according to claim 10, wherein the projection data is acquired by spiral scanning through the ray emitters and ray detectors at both ends of the C-arm. include: The C-arm is moved along a first direction, and at the same time, the ray emitter is controlled to perform a first rotation around the first direction and to emit rays, and the ray detector receives the rays emitted by the ray emitter to obtain first projection data; When the first rotation reaches a preset angle, stopping the first rotation; The C-arm is moved along a first direction, and at the same time, the ray emitter is controlled to perform a second rotation around the first direction and to emit rays, and the ray detector receives the rays emitted by the ray emitter to obtain second projection data; wherein the rotation direction of the second rotation is opposite to the rotation direction of the first rotation; The projection data is determined based on the first projection data and the second projection data.

12. The system according to claim 9, wherein the projection data is acquired by spiral scanning through the ray emitters and ray detectors at both ends of the C-arm. include: The C-arm is moved from a scanning starting point along a first direction, and at the same time, the ray emitter is controlled to rotate around the first direction and to emit rays, and the ray detector receives the rays emitted by the ray emitter to obtain first projection data; Controlling the ray emitter to stop emitting rays and returning the C-arm to the scanning starting point; The C-arm is moved from the scanning starting point along a second direction, and the ray emitter is controlled to rotate around the second direction and to emit rays, and the ray detector receives the rays emitted by the ray emitter to obtain second projection data; wherein the first direction is opposite to the second direction; The projection data is determined based on the first projection data and the second projection data.

Images