Registration method and device applied to liver ablation postoperative evaluation

Abstract

According to the registration method and device applied to liver ablation postoperative evaluation, wrong matching of an ablation area and a tumor can be prevented, external contraction of the ablation area is quantified, internal contraction of the ablation area is compensated, an image before a microwave ablation operation is aligned with an image after the microwave ablation operation, and the ablation boundary can be evaluated. The method comprises the following steps: (1) acquiring 3D images before and after a microwave ablation operation as a moving image and a fixed image; performing optimization, regularization and alternate updating to quantify the systolic field outside the ablation region and estimate a respiratory motion field; the BHE is solved to calculate a steady-state temperature field based on the position and power of the ablation needle, the TWE is solved to obtain a steady-state contraction field based on the steady-state temperature field and an ablation area external contraction field, the steady-state contraction field and the ablation area external contraction field are combined, and a total tissue contraction field is obtained; and (4) performing sequential correction of respiratory movement on the moving image, and compensating tissue contraction to obtain a compensated image.

Description

technical field [0001] The invention relates to the technical field of medical image processing, and in particular, to a registration method applied to evaluation after liver ablation, and a registration device applied to evaluation after liver ablation. Background technique [0002] The traditional registration method (LogDemons) aims to find a differential homeomorphic transformation, It aligns the moving image (m) with the fixed image (f). This spatial transformation φ is encoded by an exponential differential homeomorphic velocity field v. φ=exp(v). Typically, v is optimized by minimizing the energy function: [0003] [0004] [0005] where similarity criteria measure f, similarity. R d (v) is through the Gaussian kernel σ v A regularity criterion for smoothing v to ensure the diffeomorphism of the velocity field v. Differential homeomorphism is only applicable to homologous tissues that have consistent gray levels in the two images and can establish...

AI Technical Summary

Problems solved by technology

However, in the evaluation of the ablation boundary, the tumor becomes inconsistent with the gray scale of the ablation zone due to the gray scale change caused by the cytotoxic temperature, and the traditional registration method cannot correctly align the ablation zone and the tumor because they are not homogeneous tissues

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