Saito Hirokazu, Noda Kana, Ogasawara Koji, Atsuji Shutaro, Takaoka Hiroko, Kajihara Hiroo, Nasu Jiro, Kitaoka Mitsuhiko, Morishita Shoji, Matsushita Ikuo, Katahira Kazuhiro
Department of Gastroenterology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan.
Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan.
Radiol Case Rep. 2018 Feb 23;13(2):437-443. doi: 10.1016/j.radcr.2018.01.028. eCollection 2018 Apr.
Contrast-enhanced computed tomography using iodinated contrast media is useful for diagnosis of gastrointestinal diseases. However, contrast-induced nephropathy remains problematic for kidney diseases patients. Although current guidelines recommended the use of a minimal dose of contrast media necessary to obtain adequate images for diagnosis, obtaining adequate images with sufficient contrast enhancement is difficult with conventional computed tomography using reduced contrast media. Dual-layer spectral detector computed tomography enables the simultaneous acquisition of low- and high-energy data and the reconstruction of virtual monochromatic images ranging from 40 to 200 keV, retrospectively. Low-energy virtual monochromatic images can enhance the contrast of images, thereby facilitating reduced contrast media. In case 1, abdominal computed tomography angiography at 50 keV using 40% of the conventional dose of contrast media revealed the artery that was the source of diverticular bleeding in the ascending colon. In case 2, ischemia of the transverse colon was diagnosed by contrast-enhanced computed tomography and iodine-selective imaging using 40% of the conventional dose of contrast media. In case 3, advanced esophagogastric junctional cancer was staged and preoperative abdominal computed tomography angiography could be obtained with 30% of the conventional dose of contrast media. However, the texture of virtual monochromatic images may be a limitation at low energy.
使用碘化造影剂的对比增强计算机断层扫描对胃肠道疾病的诊断很有用。然而，对比剂肾病对肾脏疾病患者来说仍然是个问题。尽管当前指南推荐使用获得足够诊断图像所需的最小剂量造影剂，但使用减少剂量造影剂的传统计算机断层扫描很难获得具有足够对比增强的足够图像。双层光谱探测器计算机断层扫描能够同时采集低能和高能数据，并能回顾性重建40至200keV范围内的虚拟单色图像。低能虚拟单色图像可以增强图像的对比度，从而有助于减少造影剂的使用。在病例1中，使用40%常规剂量造影剂的50keV腹部计算机断层扫描血管造影显示了升结肠中憩室出血的动脉来源。在病例2中，使用40%常规剂量造影剂的对比增强计算机断层扫描和碘选择性成像诊断出横结肠缺血。在病例3中，对进展期食管胃交界癌进行了分期，并且术前腹部计算机断层扫描血管造影可以使用30%常规剂量的造影剂获得。然而，低能量时虚拟单色图像的纹理可能是一个限制因素。
