Invest Radiol. 2018 Jan;53(1):26-34. doi: 10.1097/RLI.0000000000000408.
Grating-based phase-contrast computed tomography (gb-PCCT) relies on x-ray refraction instead of absorption to generate high-contrast images in biological soft tissue. The aim of this study was to evaluate the potential of gb-PCCT for the depiction of structural changes in heart disease.
Four human heart specimens from patients with hypertensive disease, ischemic disease, dilated heart disease, and cardiac lipomatosis were examined. The gb-PCCT setup consisted of an x-ray tube (40 kV, 70 mA), grating-interferometer, and detector, and allowed simultaneous acquisition of phase- and absorption-contrast data. With histopathology as the standard of reference, myocardium (MC), fibrotic scar (FS), interstitial fibrosis (IF), and fatty tissue (FT) were visually and quantitatively evaluated. Systematic differences in absorption- and phase-contrast Hounsfield units (HUabs and HUp) were assessed.
Thirteen corresponding cross-sections were included, and MC, FS, IF, and FT were found in 13 (100%), 4 (30.8%), 7 (53.8%), and 13 (100%) cross-sections, respectively. Mean HUp/HUabs were 52.5/54.1, 86.6/69.7, 62.4/62.3, and -38.6/-258.9 for MC, FS, IF, and FT, respectively. An overlap in HUabs was observed for MC and IF (P = 0.84) but not for HUp (P < 0.01). Contrast-to-noise ratios were significantly higher in phase- than in absorption-contrast for MC/FT (35.4 vs 7.8; P < 0.01) and for MC/FS (12.3 vs 0.2; P < 0.01).
Given its superior soft tissue contrast, gb-PCCT is able to depict structural changes in different cardiomyopathies, which can currently not be obtained by x-ray absorption-based imaging methods. If current technical limitations can be overcome, gb-PCCT may evolve as a powerful tool for the anatomical assessment of cardiomyopathy.
基于光栅的相衬计算机断层扫描（gb-PCCT）依赖于 X 射线折射而不是吸收来生成生物软组织中的高对比度图像。本研究旨在评估 gb-PCCT 在心脏病结构性变化描绘中的潜力。
对来自高血压病、缺血性疾病、扩张型心脏病和心脏脂肪瘤病患者的 4 个人类心脏标本进行了检查。gb-PCCT 设备由 X 射线管（40 kV，70 mA）、光栅干涉仪和探测器组成，允许同时采集相衬和吸收衬度数据。以组织病理学为参考标准，对心肌（MC）、纤维化瘢痕（FS）、间质纤维化（IF）和脂肪组织（FT）进行了视觉和定量评估。评估了吸收和相衬 Hounsfield 单位（HUabs 和 HUp）的系统差异。
共纳入 13 个相应的横截面，在 13 个（100%）、4 个（30.8%）、7 个（53.8%）和 13 个（100%）横截面上发现了 MC、FS、IF 和 FT。MC、FS、IF 和 FT 的平均 HUp/HUabs 分别为 52.5/54.1、86.6/69.7、62.4/62.3 和-38.6/-258.9。MC 和 IF 的 HUabs 有重叠（P=0.84），但 HUp 没有重叠（P<0.01）。MC/FT（35.4 比 7.8；P<0.01）和 MC/FS（12.3 比 0.2；P<0.01）的相衬比吸收衬度的对比噪声比显著更高。
鉴于其优越的软组织对比度，gb-PCCT 能够描绘不同心肌病的结构变化，而目前基于 X 射线吸收的成像方法无法获得这些变化。如果能够克服当前的技术限制，gb-PCCT 可能会发展成为评估心肌病的一种强大工具。
