Motion compensation high-quality 4D-CBCT image reconstruction method based on bilateral filtering

Abstract

The invention discloses a motion compensation high-quality 4D-CBCT image reconstruction method based on bilateral filtering, and the method comprises the following steps: 1), building a 3D-CBCT motioncompensation reconstruction model based on an SART technology, and reconstructing a high-quality CBCT image of a reference phase (i.e., a 0% phase); 2) constructing an iterative optimization process,estimating a 4D image deformation field (DVF) model between a 0% phase image and other 4D phase images, and further solving an accurate 4D-DVF solution containing reverse sliding motion between the surfaces of the moving organs; and 3) sequentially deforming the high-quality 0% phase images according to the 4D-DVF optimal solution to obtain a final high-quality 4D-CBCT image sequence. Accurate reconstruction of the high-quality 4D-CBCT image can be realized on the basis of not changing the hardware structure of the conventional radiotherapy linear accelerator at present. Therefore, the accuracy of the image guiding and positioning in front of the SBRT (Stereotactic Body Radiation Treatment) is further improved, and the accuracy of the image guiding and positioning in front of the SBRT isfurther improved.

Description

technical field [0001] The invention is applied to precise image-guided radiotherapy during stereotactic radiotherapy (SBRT) for cancerous moving organs (such as lung cancer). Background technique [0002] SBRT treatment for lung cancer, that is, stereotactic body radiation therapy, is currently more and more widely used in the process of image-guided radiation therapy. Its therapeutic effect has been proven to be superior to traditional intensity-modulated radiation therapy (Intensity Modulated Radiation Therapy, IMRT). However, in the process of SBRT treatment, the non-flattening filter beam mode (Flattening Filter Free, FFF) based on the small field (field size less than 5x5 cm) is used to output the beam. The dose rate and intensity of the beam center are much higher than those of the intensity-modulated beam with an equalizing filter, such as figure 1 shown. Therefore, it is of great significance to accurately position the FFF beam in SBRT treatment to ensure that th...

AI Technical Summary

Problems solved by technology

Although the current international mainstream radiotherapy accelerator manufacturers have proposed a 4D-CBCT imaging functional module based on the analytical method, the imaging effect is not good, and the image quality needs to be further improved.

Although the recently launched accelerator CBCT has provided 4D-CBCT imaging function, the imaging method adopted has many artifacts and poor image quality

For some lung cancer scenarios that require precise positioning to guide SBRT treatment, it cannot play a good role in monitoring and guiding

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