CBCT image reconstruction method based on compressed sensing

Abstract

The invention discloses a CBCT image reconstruction method based on compression sensing. The CBCT data to be reconstructed are iteratively computed by using iterative algorithm. In each iteration of the iterative computation, the pre-trained dual dictionary model is used to reconstruct the image of the iterative result. The dual dictionary model includes: low-precision dictionary, high-precision dictionary; a low precision dictionary is used to sparsely express the current iterative results of the iterative computation. High-precision dictionary is used to reconstruct CBCT images using the results of low-precision dictionary sparse representation. The CBCT image reconstructed by high-precision dictionary is used as the input of the next iterative process until the acquired CBCT image reaches the predetermined accuracy, and the iterative calculation is stopped to obtain the final CBCT reconstructed image. The technical proposal provided by the invention can remarkably reduce the X-ray dose received by a patient during a single CBCT scan in image-guided radiotherapy on the premise of ensuring the clinical application of the CBCT reconstructed image, and reduce the CBCT scan time.

Description

technical field [0001] The invention relates to the technical field of image reconstruction, in particular to a CBCT image reconstruction method based on compressed sensing. Background technique [0002] As an important means of tumor treatment, radiotherapy has entered the era of precise radiotherapy technology of "precise positioning, precise planning, and precise treatment" with the application of computer technology and the development of medical physics, fully demonstrating its ability to kill tumors to the maximum extent and improve tumor control It has the technical advantages of maximally protecting the normal organs around the tumor and reducing the incidence of serious complications. Image-guided radiotherapy (IGRT), as a technical guarantee for precise radiotherapy, collects images or other signals during the current fractionation treatment setup or treatment to guide this radiotherapy and subsequent fractionation treatments. This can be correcting patient positi...

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Problems solved by technology

[0004] However, as CBCT correction has gradually become a routine technique in IGRT, a large number of transmission slices collected for CBCT three-dimensional image reconstruction lead to a certain degree of additional X-ray radiation for patients, especially a significant increase in the radiation dose to normal tissues in patients.

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