Method and system for compensating coronary artery motion in X-ray images

Abstract

A method and device for compensating coronary artery motion in X-ray images superimposes coronary arteries compensated for heartbeat and respiratory motion on X-ray fluoroscopic images in real time, providing doctors with real-time and accurate coronary artery structural information without contrast agent injection. The method includes: (1) coronary artery heartbeat motion compensation: first matching the ECG signal, and enriching the number of coronary artery structures through interpolation, densely matching to obtain a coronary artery morphological structure consistent with the heartbeat motion state, and compensating for the coronary artery motion caused by the heartbeat; (2) real-time catheter tracking: treating the catheter as a series of connected line segments, combining the catheter shape prior, and using a path search method to track the catheter structure; (3) coronary artery respiratory motion compensation: using dynamic time normalization to match the catheter structure, and designing a screening strategy to further optimize the catheter matching point pairs, calculating the average displacement of the matching point pairs to obtain the catheter translation motion, and compensating for the coronary artery motion caused by respiration.

Description

Technical Field

[0001] The present invention relates to the technical field of medical image processing, and in particular to a method for compensating coronary artery motion in X-ray images, and a device for compensating coronary artery motion in X-ray images, which accurately superimpose the coronary artery structure in an angiography image at the same imaging angle onto an X-ray fluoroscopic image, and can provide doctors with real-time and accurate coronary artery structure information without the injection of contrast agent. Background Art

[0002] Percutaneous coronary intervention (PCI) is an important clinical treatment for coronary artery disease. Doctors perform the procedure under X-ray guidance. X-ray fluoroscopy images have excellent spatial and temporal resolution, allowing them to image bones and surgical instruments, but they cannot directly image blood vessels. Contrast agent is injected into the blood vessels. Because X-rays cannot penetrate the agent, angiographic images accurately reflect the morphology and position of the vessels. Coronary arteries are subject to significant deformation due to the inevitable motion of heartbeat and respiration, necessitating repeated injections of contrast agent to visualize the morphology and position of the coronary arteries during surgery. However, contrast-induced acute kidney injury is a common complication of PCI, and the excessive use of contrast agents increases the cumulative radiation exposure of both patients and physicians. To superimpose angiographic images of the coronary artery structure from the same imaging angle on X-ray fluoroscopy images, and to provide real-time and accurate information on the morphology and position of the coronary arteries while minimizing the use of contrast agent, compensating for coronary artery motion caused by heartbeat and respiration is a crucial step.

[0003] Currently, motion compensation in X-ray image-guided interventional procedures can be broadly categorized into two methods: one involves constructing an association model with a surrogate signal as input and motion as output, and the other involves estimating image deformation for motion compensation. The first method requires the prior assumption of approximately periodic motion, resulting in discrepancies between the actual intraoperative motion pattern and the motion pattern fitted by the association model. Soft cardiac tissue is easily obscured by tissues such as the diaphragm and lungs, and imaging contrast is low. Contrast agent flow causes mismatches in coronary artery imaging regions at different times, making the second method inappropriate for direct coronary artery motion compensation. Some studies have attempted to compensate for the motion of the target anatomy by estimating the motion of a surrogate object that is consistently visible in the image and whose motion is easily estimated. This requires the surrogate and the target anatomy to assume approximately consistent motion. Summary of the Invention

[0004] In order to overcome the defects of the existing technology, the technical problem to be solved by the present invention is to provide a method for compensating coronary artery motion in X-ray images, which superimposes the coronary arteries compensated for heartbeat and respiratory motion on the X-ray fluoroscopic image in real time, and can provide doctors with real-time and accurate coronary artery structure information without the injection of contrast agent.

[0005] The technical solution of the present invention is: a method for compensating coronary artery motion in an X-ray image, the method comprising the following steps:

[0006] (1) Coronary heartbeat motion compensation: First, match the ECG signal and enrich the number of coronary structures through interpolation. Dense matching is used to obtain the coronary morphological structure consistent with the heartbeat motion state to compensate for the coronary motion caused by the heartbeat.

[0007] (2) Real-time catheter tracking: The catheter is considered as a series of connected line segments, and the catheter shape prior is combined to track the catheter structure using a path search method;

[0008] (3) Compensation for coronary respiratory motion: Dynamic time normalization is used to match the catheter structure, and a screening strategy is designed to further optimize the catheter matching point pairs. The average displacement of the matching point pairs is calculated to obtain the catheter translation motion to compensate for the coronary motion caused by respiration.

[0009] The present invention uses coronary heartbeat motion compensation to accurately compensate for coronary heartbeat motion even in the case of irregular heartbeat. Real-time catheter tracking can extract a complete catheter structure without breakage. Coronary respiratory motion compensation compensates for coronary artery motion caused by respiration through catheter translational motion, and finally obtains a coronary artery structure with accurate morphology and position. Therefore, the present invention can superimpose coronary arteries compensated for heartbeat and respiratory motion on X-ray fluoroscopic images in real time, and can provide doctors with real-time and accurate coronary artery structure information without contrast agent injection.

[0010] Also provided is a system for compensating for coronary artery motion in X-ray images, comprising:

[0011] The coronary heartbeat motion compensation module is configured to first match the ECG signal and then interpolate

[0012] Enrich the number of coronary artery structures, densely match to obtain coronary artery morphological structures consistent with the heartbeat motion state, and compensate for the coronary artery motion caused by the heartbeat; to consider the irregularity of the heartbeat, use multi-scale maximized linear cross-correlation to match ECG signals;

[0013] The real-time catheter tracking module is configured to treat the catheter as a series of connected line segments, and uses a path search method to track the catheter structure based on the catheter shape prior.

[0014] The coronary respiratory motion compensation module is configured to use dynamic time normalization to match the catheter structure, and a screening strategy is designed to further optimize the catheter matching point pairs. The average displacement of the matching point pairs is calculated to obtain the catheter translation motion to compensate for the coronary motion caused by respiration. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a flow chart of a method for compensating coronary artery motion in an X-ray image according to the present invention.

[0016] Figure 2is a flow chart of the data preprocessing steps according to the present invention.

[0017] Figure 3 is a flow chart of the coronary heartbeat motion compensation steps according to the present invention.

[0018] Figure 4 is a flow chart of the steps of real-time catheter tracking according to the present invention.

[0019] Figure 5 is a flow chart of the coronary respiratory motion compensation steps according to the present invention. DETAILED DESCRIPTION

[0020] like Figure 1 As shown, the method for compensating coronary artery motion in X-ray images comprises the following steps:

[0021] (1) Coronary heartbeat motion compensation: first match the ECG signal (i.e., electrocardiogram signal), and then

[0022] Interpolation enriches the number of coronary artery structures, and dense matching obtains coronary artery morphological structures consistent with the heartbeat motion state, compensating for the coronary artery motion caused by the heartbeat;

[0023] (2) Real-time catheter tracking: The catheter is considered as a series of connected line segments, and the catheter shape prior is combined to track the catheter structure using a path search method;

[0024] (3) Compensation for coronary respiratory motion: Dynamic time normalization is used to match the catheter structure, and a screening strategy is designed to further optimize the catheter matching point pairs. The average displacement of the matching point pairs is calculated to obtain the catheter translation motion to compensate for the coronary motion caused by respiration.

[0025] The present invention uses coronary heartbeat motion compensation to accurately compensate for coronary heartbeat motion even in the case of irregular heartbeat. Real-time catheter tracking can extract a complete catheter structure without breakage. Coronary respiratory motion compensation compensates for coronary artery motion caused by respiration through catheter translational motion, and finally obtains a coronary artery structure with accurate morphology and position. Therefore, the present invention can superimpose coronary arteries compensated for heartbeat and respiratory motion on X-ray fluoroscopic images in real time, and can provide doctors with real-time and accurate coronary artery structure information without contrast agent injection.

[0026] Preferably, there is a data preprocessing step before step (1) to obtain a dense coronary artery and duct structure sequence from the angiography image sequence.

[0027] Preferably, if Figure 2 As shown in the figure, in the data preprocessing step, a large number of angiographic images are first obtained through video interpolation to ensure a sufficiently dense coronary artery motion state. Then, a dense sequence of coronary artery and ductal structures is obtained through segmentation extraction.

[0028] Preferably, if Figure 3 As shown, in step (1), multi-scale maximization of linear cross-correlation is used to match ECG signals, which can accurately match even when the heartbeat is irregular.

[0029] Preferably, in step (1), the heartbeat motion compensation part aligns the heartbeat motion states of the fluoroscopic image and the angiography image to obtain the heartbeat motion compensated coronary structure.

[0030] Preferably, if Figure 4 As shown, in step (2), the rough center line is first extracted by enhancing the tubular structure, and then endpoint detection and bifurcation point detection are performed to obtain mutually unconnected line segments, and finally the final catheter center line is obtained by path search.

[0031] Preferably, in step (3), the respiratory motion compensation part tracks and matches the catheter structure of the fluoroscopic image and the angiography image, estimates the catheter translation motion to compensate for the coronary artery motion caused by respiration, and finally superimposes the accurate coronary artery structure on the fluoroscopic image.

[0032] Preferably, if Figure 5 As shown, in step (3), the catheter structures corresponding to the fluoroscopic image and the coronary artery compensated for heartbeat motion are first extracted respectively, and then the optimized catheter matching point pairs are obtained using dynamic time normalization and screening strategies. The average displacement of the matching point pairs is calculated to obtain the catheter translation motion, and the coronary artery motion caused by breathing is compensated, thereby obtaining the coronary artery structure compensated for heartbeat and respiratory motion.

[0033] Those skilled in the art will appreciate that all or part of the steps in the above-described method can be accomplished by instructing the relevant hardware through a program. The program can be stored in a computer-readable storage medium. When executed, the program includes the steps of the above-described method. The storage medium can be ROM / RAM, a magnetic disk, an optical disk, a memory card, etc. Therefore, corresponding to the method of the present invention, the present invention also includes a system for compensating for coronary artery motion in X-ray images. The system is generally represented in the form of functional modules corresponding to the steps of the method. The system includes:

[0034] The coronary heartbeat motion compensation module is configured to first match the ECG signal and then interpolate

[0035] Enrich the number of coronary artery structures, densely match to obtain coronary artery morphological structures consistent with the heartbeat motion state, and compensate for the coronary artery motion caused by the heartbeat; to consider the irregularity of the heartbeat, use multi-scale maximized linear cross-correlation to match ECG signals;

[0036] The real-time catheter tracking module is configured to treat the catheter as a series of connected line segments, and uses a path search method to track the catheter structure based on the catheter shape prior.

[0037] The coronary respiratory motion compensation module is configured to use dynamic time normalization to match the catheter structure, and a screening strategy is designed to further optimize the catheter matching point pairs. The average displacement of the matching point pairs is calculated to obtain the catheter translation motion to compensate for the coronary motion caused by respiration.

[0038] Preferably, the system further comprises a data pre-processing module, which is executed before the coronary heartbeat motion compensation module and is configured to obtain a dense coronary artery and duct structure sequence from the angiography image sequence.

[0039] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A method for compensating coronary artery motion in X-ray images, characterized in that: The method comprises the following steps: (1) Coronary heartbeat motion compensation: First, match the ECG signal and enrich the number of coronary structures through interpolation. Dense matching is used to obtain the coronary morphological structure consistent with the heartbeat motion state to compensate for the coronary motion caused by the heartbeat. (2) Real-time catheter tracking: The catheter is considered as a series of connected line segments, and the catheter shape prior is combined to track the catheter structure using a path search method; (3) Compensation for coronary respiratory motion: Dynamic time normalization is used to match the catheter structure, and a screening strategy is designed to further optimize the catheter matching point pairs. The average displacement of the matching point pairs is calculated to obtain the catheter translation motion to compensate for the coronary motion caused by respiration.

2. The method for compensating coronary artery motion in X-ray images according to claim 1, wherein: Before step (1), there is a data preprocessing step to obtain a dense coronary artery and duct structure sequence from the angiography image sequence.

3. The method for compensating coronary artery motion in X-ray images according to claim 2, wherein: In the data preprocessing step, a large number of angiographic images are first obtained through video interpolation to ensure sufficiently dense coronary artery motion states, and then dense coronary artery and ductal structure sequences are obtained through segmentation extraction.

4. The method for compensating coronary artery motion in X-ray images according to claim 3, wherein: In the step (1), the ECG signals are matched using multi-scale maximized linear cross-correlation.

5. The method for compensating coronary artery motion in X-ray images according to claim 4, wherein: In the step (1), the heartbeat motion compensation part aligns the heartbeat motion states of the fluoroscopic image and the angiography image to obtain the heartbeat motion compensated coronary artery structure.

6. The method for compensating coronary artery motion in X-ray images according to claim 5, wherein: In the step (2), the rough center line is first extracted by enhancing the tubular structure, and then endpoint detection and bifurcation point detection are performed to obtain mutually unconnected line segments, and finally the final catheter center line is obtained by path search.

7. The method for compensating coronary artery motion in X-ray images according to claim 6, wherein: In step (3), the respiratory motion compensation part tracks and matches the catheter structure of the fluoroscopic image and the angiographic image, estimates the catheter translational motion to compensate for the coronary artery motion caused by respiration, and finally superimposes the accurate coronary artery structure on the fluoroscopic image.

8. The method for compensating coronary artery motion in X-ray images according to claim 7, wherein: In step (3), the catheter structures corresponding to the fluoroscopic image and the coronary artery compensated for heartbeat motion are first extracted respectively, and then the optimized catheter matching point pairs are obtained using dynamic time normalization and screening strategies. The average displacement of the matching point pairs is calculated to obtain the catheter translation motion, and the coronary artery motion caused by respiration is compensated, thereby obtaining the coronary artery structure compensated for heartbeat and respiratory motion.

9. A system for compensating for coronary artery motion in X-ray images, characterized in that: It includes: The coronary heartbeat motion compensation module is configured to match ECG signals first and then enrich the number of coronary structures through interpolation. Dense matching is used to obtain coronary morphological structures consistent with the heartbeat motion state, compensating for coronary artery motion caused by the heartbeat. To account for irregular heartbeats, multi-scale maximization of linear cross-correlation is used to match ECG signals. The real-time catheter tracking module is configured to treat the catheter as a series of connected line segments, and uses a path search method to track the catheter structure based on the catheter shape prior. The coronary respiratory motion compensation module is configured to use dynamic time normalization to match the catheter structure, and a screening strategy is designed to further optimize the catheter matching point pairs. The average displacement of the matching point pairs is calculated to obtain the catheter translation motion to compensate for the coronary motion caused by respiration.

10. The system for compensating coronary artery motion in X-ray images according to claim 9, wherein: The system also includes a data pre-processing module that is executed before the coronary heartbeat motion compensation module and is configured to obtain a dense coronary artery and ductal structure sequence from the angiography image sequence.

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