Department of Radiology, University of Yamanashi, 1110 Shimokawato, Chuo, Yamanashi 400-3898, Japan.
Jpn J Radiol. 2011 Jul;29(6):405-12. doi: 10.1007/s11604-011-0571-0. Epub 2011 Jul 24.
The aim of this study was to determine a standard deviation (SD) that most reduces the radiation dose without sacrificing the diagnostic accuracy of thin-section computed tomography (CT) for clinical use.
A total of 120 patients were examined by multidetector CT. They were assigned to one of four SD groups: 8, 9, 11, and 12. Each SD group consisted of 30 patients. The CT images of the same patients with SD10 that had formerly been examined were used for comparison. Two radiologists independently evaluated the degrees of image noise and diagnostic acceptability of the pulmonary diseases using a point score grading system. We compared the scores between each SD and the SD10 group.
Generally, image noise was significantly more prominent in the higher-SD groups. The mean score of diagnostic acceptability was significantly lower in the SD12 group (4.2 ± 1.6) than in the SD10 group (4.6 ± 1.1) group (P < 0.001), whereas no difference was present between the SD8 (4.9 ± 0.7), SD9 (4.8 ± 1.0), and SD11 (4.4 ± 1.5) groups and the SD10 group (4.7 ± 1.1, 4.6 ± 1.4, 4.6 ± 1.1, respectively).
Thin-section CT with SD12 is not acceptable. SD11 seems to be the setting with the lowest radiation dose while providing acceptable imaging quality for pulmonary thin-section CT.
本研究旨在确定一个标准差（SD），在不牺牲临床用薄层计算机断层扫描（CT）诊断准确性的情况下，最大限度地降低辐射剂量。
共对 120 例患者进行多排 CT 检查。将他们分为四组 SD 组之一：8、9、11 和 12。每组 30 例患者。使用先前检查过的 SD10 的同一患者的 CT 图像进行比较。两名放射科医生使用评分分级系统独立评估图像噪声程度和肺部疾病的诊断可接受性。我们比较了每个 SD 与 SD10 组之间的评分。
通常，图像噪声在较高 SD 组中更为明显。SD12 组（4.2 ± 1.6）的诊断可接受性平均评分明显低于 SD10 组（4.6 ± 1.1）（P < 0.001），而 SD8（4.9 ± 0.7）、SD9（4.8 ± 1.0）和 SD11（4.4 ± 1.5）组与 SD10 组之间无差异（4.7 ± 1.1、4.6 ± 1.4、4.6 ± 1.1）。
SD12 的薄层 CT 不可接受。SD11 似乎是在提供可接受的肺部薄层 CT 成像质量的同时，辐射剂量最低的设置。
