Department of Engineering Physics, Tsinghua University, Haidian District, Beijing, China.
Key Laboratory of Particle & Radiation Imaging (Tsinghua University) of Ministry of Education, Haidian District, Beijing, China.
J Xray Sci Technol. 2019;27(3):503-516. doi: 10.3233/XST-180453.
Grating-based X-ray phase-contrast imaging (GPCI) has received growing interests in recent years due to its high capability of visualizing soft tissue. Breast imaging is one of the most promising candidates for the first clinical application of this imaging modality.
In this work, quantitative breast tissue characterization based on GPCI computed tomography (CT) is investigated with a laboratory X-ray tube through a comparison between attenuation-based CT images and phase-contrast CT images.
The Hounsfield units (HU) scale was introduced to phase-contrast images due to its wide application in clinical medicine. In this work, instead of water, plastic cylinders composed of polyethylene terephthalate (PET) was treated as the calibration material. An alternative test-retest reliability (TRR) was presented to evaluate the repeatability of GPCI. Comparison between attenuation-based CT imaging and GPCI CT imaging was operated with the use of statistical analysis methods like histograms and receiver operating characteristic (ROC) curves.
The determined mean TRR related to cylinders is slightly larger in phase-contrast imaging (0.93) than that in attenuation-based imaging (0.89). With respect to distinguishing breast tissues, the AUC (area under curve) values of ROC curves of phase-contrast images are higher than that of attenuation-based images.
An ex vivo study of GPCI shows that it is a stable imaging modality for visualizing the breast tissue with good repeatability, and that it could be of potential for the diagnosis of breast cancer as well.
基于光栅的 X 射线相衬成像（GPCI）近年来因其能够高清晰地显示软组织而受到越来越多的关注。乳腺成像是该成像模式首次临床应用最有前途的候选者之一。
本研究通过对比衰减 CT 图像和相衬 CT 图像，利用实验室 X 射线管对基于 GPCI 的乳腺组织定量特征进行了研究。
由于其在临床医学中的广泛应用，Hounsfield 单位（HU）标度被引入到相衬图像中。在这项工作中，代替水，由聚对苯二甲酸乙二醇酯（PET）制成的塑料圆柱被用作校准材料。提出了一种替代测试-再测试可靠性（TRR）来评估 GPCI 的重复性。使用直方图和接收器操作特性（ROC）曲线等统计分析方法对衰减 CT 成像和 GPCI CT 成像进行了比较。
相对于衰减成像（0.89），相衬成像中确定的与圆柱相关的平均 TRR 稍大（0.93）。在区分乳腺组织方面，相衬图像的 ROC 曲线的 AUC（曲线下面积）值高于衰减图像的 AUC 值。
GPCI 的离体研究表明，它是一种用于可视化乳腺组织的稳定成像方式，具有良好的可重复性，并且可能对乳腺癌的诊断具有潜在的应用价值。
