The Detector System Design for the Grating-based Phase Contrast Imaging CT Prototype

TL;DR

This paper presents a detailed design of a detector system for a grating-based phase contrast CT prototype, enhancing soft tissue imaging contrast by leveraging phase-sensitive X-ray methods.

Contribution

The paper introduces a novel detector system design with 43 silicon photodiode modules, high resolution, and integrated electronics for phase contrast CT imaging.

Findings

Detector resolution up to 14.6 bits

Integral nonlinearity below 0.1% for all pixels

Successful system integration and data transmission

Abstract

In the hard X rays domain, the phase shift of the wave passing through the soft materials like tissues is typically three orders of magnitude larger than the absorption. Therefore the phase-sensitive X-ray imaging methods can obtain substantially increased contrast over conventional absorption-based imaging. In this paper, we present a detector system design for the computed tomography(CT) prototype which based on the grating-based phase contrast imaging(GBPCI) method. This system consists of 43 Hamamatsu silicon photodiode S12058(X) modules including 16512 pixels. Each module can provide 384(16*24) pixels, which the minimum pixel size is 0.75mm*1mm. The front-end readout electronics(FEE) of each module complete the analog-to-digital conversion, the digital processing, and the data transmission. All digitized data from 43 detector module are transmitted to the control system through the data collection boards. The test result shows that the efficient resolution of the detector system is up to 14.6bit. For all pixels, the integral nonlinearity is no more than 0.1%.