Goodenough D J, Levy J R, Kasales C
The George Washington University, Department of Radiology, Washington, DC 20037, USA.
Comput Med Imaging Graph. 1998 May-Jun;22(3):247-55. doi: 10.1016/s0895-6111(98)00020-2.
This paper reports on the development of a new phantom for spiral CT. The phantom meets the increased demands on phantom z-axis uniformity in order that objects from the CT slice, immediately above and below the CT slice of interest, do not contribute perturbing information to the reconstructed CT slice.
The phantom depends on formulation of tissue-like materials that can be cast and produced in both geometric and anthropomorphic shapes with sufficient z-axis length to enable unperturbed CT slices of test objects of interest. These materials are then used to produce a series of test objects of CT image quality including low contrast samples that do not require volume averaging or mixing of solutions, and that can reflect sub-slice thickness test objects and supra-slice thickness test objects.
The overall phantom and its individual test objects provides meaningful tests of spiral CT image quality including slice sensitivity, CT number linearity and tests of high and low contrast resolution. Schematic designs and actual CT scans are shown.
The new spiral phantom appears to meet the increased demands of spiral CT on phantom design, particularly z-axis length, and requirements for low contrast resolution test objects.
本文报告一种新型螺旋CT体模的研制情况。该体模满足了对体模z轴均匀性日益增长的要求，以使感兴趣的CT层面上方和下方CT层面中的物体不会对重建的CT层面造成干扰信息。
该体模依赖于类似组织材料的配方，这些材料可以铸造成几何形状和人体形状，且具有足够的z轴长度，以获取感兴趣测试物体的无干扰CT层面。然后使用这些材料制作一系列CT图像质量测试物体，包括不需要溶液体积平均或混合的低对比度样本，并且能够反映亚层面厚度测试物体和超层面厚度测试物体。
整个体模及其各个测试物体为螺旋CT图像质量提供了有意义的测试，包括层面敏感度、CT值线性以及高、低对比度分辨率测试。展示了示意图设计和实际CT扫描图像。
新型螺旋体模似乎满足了螺旋CT对体模设计日益增长的要求，特别是z轴长度要求，以及对低对比度分辨率测试物体的要求。
