Double regularization medical CT image blind restoration reconstruction based on proximal alternating direction method of multipliers

Jingyu Zhang,Yuan Zhang,Jianfu Teng,Yunshan Sun

doi:10.1186/s13640-017-0218-x

Abstract

To solve the problem of CT image degradation, a double regularization CT image blind restoration reconstruction method was proposed. The objective function including both a clear image and point spread function was established. To avoid the over-smoothing phenomenon and protect the detail, the objective function includes two constraint regularization terms. They are total variation (TV) and wavelet sparsity respectively. The objective function was solved by the alternating direction multiplier method (ADMM), and the optimal solution was obtained. Firstly, the CT image blind restoration reconstruction was decomposed into two sub-problems: reconstructed image estimation and point spread function estimation. Furthermore, each sub-problem can be solved by the proximal alternating direction method of multipliers. Finally, the CT image blind restoration reconstruction was realized. The experimental results show that the proposed algorithm takes into account the degradation effect of projection data, and the proposed algorithm is superior to other existing algorithms in the subjective visual effect. At the same time, in the aspect of objective evaluation, the proposed algorithm improves the objective image quality metrics such as peak signal-to-noise ratio (PSNR), structural similarity index metric (SSIM), and universal image quality index (UIQI).

Highlights

Computer tomography (CT) is that X-ray beam is used to scan some certain thickness parts of the body
Each projection data was used by FBP, SART, total variation (TV) regularization, and the algorithm proposed for image reconstruction
All the reconstruction methods are simulated at the same degradation condition

Summary

Introduction

Computer tomography (CT) is that X-ray beam is used to scan some certain thickness parts of the body. X-ray through the detection layer is received by the detector. In the imaging and transmission process, CT image will be affected by many factors, such as electronic radiation detection effect of defocus blur, detector number and spacing, frame geometry, Medical CT image blind restoration algorithm use only CT degradation image of the CT system to estimate the point spread function. Jiang et al [3] firstly proposed the concept of medical CT blind restoration. They used the expectation maximization strategy to estimate point spread function and image restoration.

Methods

Results

Discussion

Conclusion