Department of Radiology (J.S.N., L.N., B.C.A., J.T.D., A.D., R.G., D.M., C.M.M., V.P., G.R.S.), Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Medical Physics Graduate Program (J.B.S., E.S., T.R.), and Departments of Biomedical Engineering, Electrical and Computer Engineering, and Physics (E.S.), Duke University Medical Center, Box 3808, Durham, NC 27710; Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, NC (A.E., B.Z.); and Department of Radiology, Stanford University School of Medicine, Stanford, Calif (B.N.P., D.P.F.).
Radiol Imaging Cancer. 2019 Sep 27;1(1):e190027. doi: 10.1148/rycan.2019190027. eCollection 2019 Sep.
To create and validate a systematic observer performance platform for evaluation of simulated liver lesions at pediatric CT and to test this paradigm to measure the effect of radiation dose reduction on detection performance and reader confidence.
Thirty normal pediatric (from patients aged 0-10 years) contrast material-enhanced, de-identified abdominal CT scans obtained from July 1, 2012, through July 1, 2016, were retrospectively collected from the clinical database. The study was exempt from institutional review board approval. Zero to three simulated, low-contrast liver lesions (≤6 mm) were digitally inserted by using software, and noise was added to simulate reductions in volume CT dose index (representing radiation dose estimation) of 25% and 50%. Pediatric, abdominal, and resident radiologists (three of each) reviewed 90 data sets in three sessions using an online interface, marking each lesion location and rating confidence (scale, 0-100). Statistical analysis was performed by using software.
Mixed-effects models revealed a significant decrease in detection sensitivity as radiation dose decreased ( < .001). The mean confidence of the full-dose and 25% dose reduction examinations was significantly higher than that of the 50% dose reduction examinations ( = .011 and .012, respectively) but not different from one another ( = .866). Dose was not a significant predictor of time to complete each case, and subspecialty was not a significant predictor of sensitivity or false-positive results.
Sensitivity for lesion detection significantly decreased as dose decreased; however, confidence did not change between the full-dose and 25% reduced-dose scans. This suggests that readers are unaware of this decrease in performance, which should be accounted for in clinical dose reduction efforts. Abdomen/GI, CT, Liver, Observer Performance, Pediatrics, Perception Image© RSNA, 2019.
创建和验证用于评估儿科 CT 模拟肝脏病变的系统观测者性能平台，并测试该方法以衡量降低辐射剂量对检测性能和观察者信心的影响。
本回顾性研究于 2012 年 7 月 1 日至 2016 年 7 月 1 日从临床数据库中收集了 30 例经证实为正常的儿科（年龄 0-10 岁）增强对比剂腹部 CT 扫描。该研究获得了机构审查委员会的豁免批准。使用软件在 0-3 个模拟的低对比度肝脏病变（≤6mm）中插入数字病变，并添加噪声来模拟体剂量 CT 指数（代表辐射剂量估计）降低 25%和 50%。由三位儿科、腹部和住院医师放射科医生（各 3 位）在三个会话中使用在线界面审查了 90 个数据集，标记每个病变位置并进行信心评分（0-100 分）。通过使用软件进行统计分析。
混合效应模型显示，随着辐射剂量的降低，检测敏感性显著下降（<0.001）。全剂量和 25%剂量降低检查的平均置信度显著高于 50%剂量降低检查（分别为<.011 和<.012），但彼此之间无显著差异（=.866）。剂量不是完成每个病例时间的显著预测因子，亚专业也不是敏感性或假阳性结果的显著预测因子。
随着剂量的降低，病变检测的敏感性显著降低；然而，在全剂量和 25%降低剂量扫描之间，信心没有变化。这表明，观察者没有意识到性能的这种下降，在临床剂量降低工作中应考虑到这一点。腹部/胃肠道，CT，肝脏，观测者性能，儿科，感知成像©RSNA，2019。
