锥束微焦点CT系统对比度灵敏度测量研究

Measurement of Contrast Sensitivity of Micro-CT System

摘要: 对比度灵敏度是描述计算机断层成像（CT）系统分辨图像细节特征能力的参数，其主要受图像统计噪声水平的影响。本文介绍了CT对比度灵敏度的测量方法，并用直径50 mm的均匀有机玻璃圆柱作样品测量225 kV-3D-ICT系统的对比度灵敏度，在X光机电压为160 kV的条件下，得出在0.3 mm×0.3 mm×0.3 mm范围内的对比度灵敏度约为1%。并讨论了系统的稳定性、硬化校正和重建滤波参数对测量结果的影响。

Abstract: Contrast sensitivity describes the ability of the micro-CT system to reproduce object composition, which mainly depends on the noise of the image. The method of measuring the contrast sensitivity was introduced. A phantom with 50 mm diameter was measured on the system 225 kV-3D-micro ICT and it is found the contrast sensitivity is about 1% at the range of 0.3 mm×0.3 mm×0.3 mm. In addition, the system stability, beam hardening and the reconstruction parameter which affect the measurement result were studied.