Department of Radiology, Seoul National University Bundang Hospital, Seongnam, Korea.
Aerospace Medical Group, Air Force Education and Training Command, Jinju, Korea.
Korean J Radiol. 2022 Apr;23(4):413-425. doi: 10.3348/kjr.2021.0504. Epub 2022 Jan 27.
We compared appendiceal visualization on 2-mSv CT vs. conventional-dose CT (median 7 mSv) in adolescents and young adults and analyzed the undesirable clinical and diagnostic outcomes that followed appendiceal nonvisualization.
A total of 3074 patients aged 15-44 years (mean ± standard deviation, 28 ± 9 years; 1672 female) from 20 hospitals were randomized to the 2-mSv CT or conventional-dose CT group (1535 vs. 1539) from December 2013 through August 2016. A total of 161 radiologists from 20 institutions prospectively rated appendiceal visualization (grade 0, not identified; grade 1, unsure or partly visualized; and grade 2, clearly and entirely visualized) and the presence of appendicitis in these patients. The final diagnosis was based on CT imaging and surgical, pathologic, and clinical findings. We analyzed undesirable clinical or diagnostic outcomes, such as negative appendectomy, perforated appendicitis, more extensive than simple appendectomy, delay in patient management, or incorrect CT diagnosis, which followed appendiceal nonvisualization (defined as grade 0 or 1) and compared the outcomes between the two groups.
In the 2-mSv CT and conventional-dose CT groups, appendiceal visualization was rated as grade 0 in 41 (2.7%) and 18 (1.2%) patients, respectively; grade 1 in 181 (11.8%) and 81 (5.3%) patients, respectively; and grade 2 in 1304 (85.0%) and 1421 (92.3%) patients, respectively ( < 0.001). Overall, undesirable outcomes were rare in both groups. Compared to the conventional-dose CT group, the 2-mSv CT group had slightly higher rates of perforated appendicitis (1.1% [17] vs. 0.5% [7], = 0.06) and false-negative diagnoses (0.4% [6] vs. 0.0% [0], = 0.01) following appendiceal nonvisualization. Otherwise, these two groups were comparable.
The use of 2-mSv CT instead of conventional-dose CT impairs appendiceal visualization in more patients. However, appendiceal nonvisualization on 2-mSv CT rarely leads to undesirable clinical or diagnostic outcomes.
我们比较了 2 毫西弗 CT 与常规剂量 CT（中位数 7 毫西弗）在青少年和年轻成年人中的阑尾显影效果，并分析了阑尾不显影后出现的不良临床和诊断结局。
2013 年 12 月至 2016 年 8 月，共有 20 家医院的 3074 名年龄在 15-44 岁（平均 ± 标准差，28 ± 9 岁；1672 名女性）的患者被随机分配至 2 毫西弗 CT 组或常规剂量 CT 组（1535 名 vs. 1539 名）。来自 20 家机构的 161 名放射科医生前瞻性地评估了这些患者的阑尾显影（0 级，未识别；1 级，不确定或部分显影；2 级，清晰且完全显影）和阑尾炎的存在。最终诊断基于 CT 成像和手术、病理和临床发现。我们分析了阑尾不显影（定义为 0 级或 1 级）后出现的不良临床或诊断结局，如阴性阑尾切除术、穿孔性阑尾炎、比单纯阑尾切除术更广泛、患者管理延迟或 CT 诊断错误，并比较了两组之间的结局。
在 2 毫西弗 CT 组和常规剂量 CT 组中，分别有 41 名（2.7%）和 18 名（1.2%）患者的阑尾显影为 0 级；181 名（11.8%）和 81 名（5.3%）患者的阑尾显影为 1 级；1304 名（85.0%）和 1421 名（92.3%）患者的阑尾显影为 2 级（<0.001）。总体而言，两组的不良结局都很少见。与常规剂量 CT 组相比，2 毫西弗 CT 组阑尾不显影后穿孔性阑尾炎的发生率略高（1.1%[17] vs. 0.5%[7]，=0.06）和假阴性诊断率（0.4%[6] vs. 0.0%[0]，=0.01）也略高。除此之外，这两组没有其他差异。
使用 2 毫西弗 CT 代替常规剂量 CT 会使更多患者的阑尾显影不佳。然而，2 毫西弗 CT 下的阑尾不显影很少导致不良的临床或诊断结局。
