US-12626377-B2 - Systems and methods for image registration

Abstract

Systems and methods for image registration are provided. The method may include obtaining a reference image of an object ( 510 ); the object includes a target volume; determining a registration mask associated with a region of interest (ROI) based on the reference image ( 520 ), the ROI includes at least a portion of the target volume; obtaining a target image of the object ( 530 ); and performing an image registration on the reference image and the target image based on the registration mask ( 540 ).

Inventors

• Hongcheng YANG
• Jonathan Maltz

Assignees

• SHANGHAI UNITED IMAGING HEALTHCARE CO., LTD.

Dates

Publication Date

20260512

Application Date

20230201

Claims (20)

1. 1 . A system for image registration, comprising: at least one storage device storing executable instructions, and at least one processor in communication with the at least one storage device, when executing the executable instructions, causing the system to perform operations including: obtaining a reference image of an object, the reference image including a target volume; determining a registration mask associated with a region of interest (ROI) based on the reference image, the ROI including at least a portion of the target volume, wherein the registration mask is configured to exclude at least a portion of one or more interference structures, and the at least a portion of the one or more interference structures locates in the ROI; obtaining a target image of the object, the target image including the target volume; and performing an image registration on the reference image and the target image based on the registration mask.
2. 2 . The system of claim 1 , wherein the determining the registration mask associated with the ROI based on the reference image includes: generating an intermediate image by removing image information outside the ROI from the reference image; and determining the registration mask associated with the ROI based on the intermediate image.
3. 3 . The system of claim 2 , wherein the determining the registration mask associated with the ROI based on the intermediate image includes: performing a filtering operation on the intermediate image; and determining the registration mask associated with the ROI based on the filtered intermediate image.
4. 4 . The system of claim 1 , wherein the determining the registration mask associated with the ROI based on the reference image includes: determining a preliminary mask including the ROI based on the reference image; identifying the one or more interference structures at least partially located in the ROI in the reference image; determining an auxiliary mask including the one or more interference structures; and determining the registration mask associated with the ROI based on the preliminary mask and the auxiliary mask.
5. 5 . The system of claim 4 , wherein the identifying the one or more interference structures at least partially located in the ROI in the reference image includes: automatically segmenting the one or more interference structures from the reference image based on a preset rule.
6. 6 . The system of claim 5 , wherein the preset rule includes at least one of a structure type, a structure label, or time information associated with the reference image.
7. 7 . The system of claim 4 , wherein the one or more interference structures include at least one of a moving organ or a moving tissue.
8. 8 . The system of claim 7 where the moving organ or moving tissues are determined from cine reference images.
9. 9 . The system of claim 7 where the moving organ or moving tissues are determined from cine target images.
10. 10 . The system of claim 7 where the moving organ or moving tissues are determined from motion characteristics of organs or tissues identified in the target or reference images.
11. 11 . The system of claim 4 , wherein the one or more interference structures include at least one of a heart, a lung, a diaphragm, a bladder, or a rectum.
12. 12 . The system of claim 4 , wherein the determining the registration mask associated with the ROI based on the preliminary mask and the auxiliary mask includes: determining the registration mask by combining the preliminary mask and the auxiliary mask.
13. 13 . The system of claim 4 , wherein the determining the registration mask associated with the ROI based on the preliminary mask and the auxiliary mask includes: determining the registration mask by multiplying the preliminary mask and the auxiliary mask.
14. 14 . The system of claim 1 , wherein the performing the image registration on the reference image and the target image based on the registration mask includes: determining a masked reference image by applying the registration mask on the reference image; determining a masked target image by applying the registration mask on the target image; and determining one or more shift parameters based on the masked reference image and the masked target image.
15. 15 . The system of claim 14 , wherein the determining the one or more shift parameters based on the masked reference image and the masked target image includes: for each of one or more target regions in the masked target image, determining a similarity value between the target region and a corresponding reference region in the masked reference image; and determining the one or more shift parameters based on one or more similarity values corresponding to the one or more target regions.
16. 16 . The system of claim 1 , wherein the reference image and the target image are acquired at a same respiratory phase.
17. 17 . The system of claim 16 , wherein both the reference image and the target image are an average image of a plurality of images acquired within a predetermined interval of a respiratory cycle of the object.
18. 18 . A method for image registration, implemented on a computing device having at least one processor and at least one storage device, the method comprising: obtaining a reference image of an object, the reference image including a target volume; determining a registration mask associated with a region of interest (ROI) based on the reference image, the ROI including at least a portion of the target volume, wherein the registration mask excludes at least a portion of one or more interference structures, and the at least a portion of the one or more interference structures locates in the ROI; obtaining a target image of the object, the target image including the target volume; and performing an image registration on the reference image and the target image based on the registration mask.
19. 19 . The method of claim 18 , wherein the performing the image registration on the reference image and the target image based on the registration mask includes: determining a masked reference image by applying the registration mask on the reference image; determining a masked target image by applying the registration mask on the target image; and determining one or more shift parameters based on the masked reference image and the masked target image.
20. 20 . A non-transitory computer readable medium, comprising at least one set of instructions for image registration, wherein when executed by at least one processor of a computing device, the at least one set of instructions direct the at least one processor to perform operations including: obtaining a reference image of an object, the reference image including a target volume; determining a registration mask associated with a region of interest (ROI) based on the reference image, the ROI including at least a portion of the target volume, wherein the registration mask excludes at least a portion of one or more interference structures, and the at least a portion of the one or more interference structures locates in the ROI; obtaining a target image of the object, the target image including the target volume; and performing an image registration on the reference image and the target image based on the registration mask.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Patent Application No. PCT/CN2020/110257, filed on Aug. 20, 2020, the entire contents of which are hereby incorporated by reference. TECHNICAL FIELD The present disclosure generally relates to image processing, and more particularly, relates to systems and methods for image registration. BACKGROUND Image-guided radiation therapy (IGRT) is a form of radiation therapy that is widely used in clinical treatment for many types of cancers. During a radiation therapy process, a treatment image acquired before or during a radiation treatment often needs to be registered with a planning image generated in advance for planning the radiation treatment, so that the radiation treatment can be accurately delivered to a target volume (e.g., a tumor) of an object (e.g., a patient) according to the treatment plan. However, some interference features (e.g., a moving organ or tissue) may significantly affect a registration result between the treatment image and the planning image, which influences subsequent treatment and/or clinical diagnosis. Thus, it is desirable to develop systems and methods for image registration to remove or reduce the influence of the interference structures, thereby improving registration accuracy. SUMMARY According to an aspect of the present disclosure, a system for image registration is provided. The system may include at least one storage device storing executable instructions and at least one processor in communication with the at least one storage device. When executing the executable instructions, the at least one processor is configured to cause the system to perform operations. The operations may include obtaining a reference image of an object, the reference image including a target volume. The operations may further include determining a registration mask associated with a region of interest (ROI) based on the reference image, the ROI including at least a portion of the target volume. The operations may further include obtaining a target image of the object, the target image including the target volume. The operations may further include performing an image registration on the reference image and the target image based on the registration mask. In some embodiments, to determine the registration mask associated with the ROI based on the reference image, the operations may include generating an intermediate image by removing image information outside the ROI from the reference image; and determining the registration mask associated with the ROI based on the intermediate image. In some embodiments, to determine the registration mask associated with the ROI based on the intermediate image, the operations may include performing a filtering operation on the intermediate image; and determining the registration mask associated with the ROI based on the filtered intermediate image. In some embodiments, to determine the registration mask associated with the ROI based on the reference image, the operations may include determining a preliminary mask including the ROI based on the reference image; identifying one or more interference structures at least partially located in the ROI in the reference image; determining an auxiliary mask including the one or more interference structures; and determining the registration mask associated with the ROI based on the preliminary mask and the auxiliary mask. In some embodiments, to identify the one or more interference structures at least partially located in the ROI in the reference image, the operations may include automatically segmenting the one or more interference structures from the reference image based on a preset rule. In some embodiments, the preset rule includes at least one of a structure type, a structure label, or time information associated with the reference image. In some embodiments, the one or more interference structures may include at least one of a moving organ or a moving tissue. In some embodiments, the moving organ or moving tissues are determined from cine reference images. In some embodiments, the moving organ or moving tissues are determined from cine target images. In some embodiments, the moving organ or moving tissues are determined from motion characteristics of organs or tissues identified in the target or reference images. In some embodiments, the one or more interference structures include at least one of a heart, a lung, a diaphragm, a bladder, or a rectum. In some embodiments, to perform the image registration on the reference image and the target image based on the registration mask, the operations may include determining a masked reference image by applying the registration mask on the reference image; determining a masked target image by applying the registration mask on the target image; and determining one or more shift parameters based on the masked reference image and the masked target image. In some embodiments, to determine t