A distance-driven deconvolution method for CT image-resolution improvement

• Published in: Journal of the Korean Physical Society Vol. 69; no. 12; pp. 1830 - 1833
• Main Authors: Han, Seokmin, Choi, Kihwan, Yoo, Sang Wook, Yi, Jonghyon
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01.12.2016; Springer Nature B.V; 한국물리학회
• Subjects: Algorithms; Blurring; Computed tomography; Deconvolution; Field of view; High resolution; Image resolution; Kernels; Mathematical and Computational Physics; Medical imaging; Modulation transfer function; Optical communication; Particle and Nuclear Physics; Physics; Physics and Astronomy; Point spread functions; Spatial resolution; Theoretical; X ray sources; X ray tubes; 물리학; CT; PSF; Deconvolution; Resolution
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.69.1830

The purpose of this research is to achieve high spatial resolution in CT (computed tomography) images without hardware modification. The main idea is to consider geometry optics model, which can provide the approximate blurring PSF (point spread function) kernel, which varies according to the distance from the X-ray tube to each point. The FOV (field of view) is divided into several band regions based on the distance from the X-ray source, and each region is deconvolved with a different deconvolution kernel. As the number of subbands increases, the overshoot of the MTF (modulation transfer function) curve increases first. After that, the overshoot begins to decrease while still showing a larger MTF than the normal FBP (filtered backprojection). The case of five subbands seems to show balanced performance between MTF boost and overshoot minimization. It can be seen that, as the number of subbands increases, the noise (STD) can be seen to show a tendency to decrease. The results shows that spatial resolution in CT images can be improved without using high-resolution detectors or focal spot wobbling. The proposed algorithm shows promising results in improving spatial resolution while avoiding excessive noise boost.