Department of Radiology, Stanford University Medical Center, 300 Pasteur Drive, Room S-072, Stanford, CA 94305-5105, USA.
Eur Radiol. 2010 Mar;20(3):549-57. doi: 10.1007/s00330-009-1596-y. Epub 2009 Sep 16.
The diagnostic performance of radiologists using incremental CAD assistance for lung nodule detection on CT and their temporal variation in performance during CAD evaluation was assessed.
CAD was applied to 20 chest multidetector-row computed tomography (MDCT) scans containing 190 non-calcified > or =3-mm nodules. After free search, three radiologists independently evaluated a maximum of up to 50 CAD detections/patient. Multiple free-response ROC curves were generated for free search and successive CAD evaluation, by incrementally adding CAD detections one at a time to the radiologists' performance.
The sensitivity for free search was 53% (range, 44%-59%) at 1.15 false positives (FP)/patient and increased with CAD to 69% (range, 59-82%) at 1.45 FP/patient. CAD evaluation initially resulted in a sharp rise in sensitivity of 14% with a minimal increase in FP over a time period of 100 s, followed by flattening of the sensitivity increase to only 2%. This transition resulted from a greater prevalence of true positive (TP) versus FP detections at early CAD evaluation and not by a temporal change in readers' performance. The time spent for TP (9.5 s +/- 4.5 s) and false negative (FN) (8.4 s +/- 6.7 s) detections was similar; FP decisions took two- to three-times longer (14.4 s +/- 8.7 s) than true negative (TN) decisions (4.7 s +/- 1.3 s).
When CAD output is ordered by CAD score, an initial period of rapid performance improvement slows significantly over time because of non-uniformity in the distribution of TP CAD output and not to a changing reader performance over time.
评估放射科医师在 CT 上使用增量 CAD 辅助检测肺结节的诊断性能及其在 CAD 评估过程中的性能变化。
将 CAD 应用于 20 例胸部多排螺旋 CT（MDCT）扫描，包含 190 个非钙化>或=3mm 的结节。在自由搜索后，三位放射科医师独立评估了每位患者最多达 50 次的 CAD 检测。通过逐步将 CAD 检测结果添加到放射科医师的表现中，为自由搜索和连续 CAD 评估生成了多个多反应接收者操作特性曲线。
自由搜索的敏感性为 53%（范围为 44%-59%），假阳性（FP）率为 1.15/患者，随着 CAD 的应用增加到 69%（范围为 59%-82%），FP 率为 1.45/患者。CAD 评估最初导致敏感性急剧上升 14%，而在 100 秒的时间段内 FP 仅略有增加，随后敏感性的增加趋于平稳，仅增加 2%。这种转变是由于在早期 CAD 评估中 TP 与 FP 检测的患病率较高，而不是由于读者表现的时间变化所致。TP（9.5 秒+/-4.5 秒）和 FN（8.4 秒+/-6.7 秒）检测的时间相似；FP 决策比 TN 决策（4.7 秒+/-1.3 秒）长 2 到 3 倍（14.4 秒+/-8.7 秒）。
当 CAD 输出按 CAD 评分排序时，由于 TP CAD 输出的分布不均匀，而不是由于读者表现随时间的变化，初始性能快速提高的阶段会显著放缓。
