Malich A, Azhari T, Böhm T, Fleck M, Kaiser W A
Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University Jena, Bachstrasse 18, 07740 Jena, Germany.
Eur J Radiol. 2000 Dec;36(3):170-4. doi: 10.1016/s0720-048x(00)00189-3.
To test the reproducibility of markings on mammography films set by a commercial computer aided detection (CAD) system.
One hundred unilateral mammography examinations (each in CC and MLO) of 100 patients with mammographically detected suspicious foci, which were histopathologically proven to be malignant, were scanned three times with the CAD system, retrospectively. Every fifth patient of the institutional tumor case sampler was enrolled in the study. Only cases with one visible lesion were included in the study. Reproducibility and sensitivity (in both the strict and the broader sense) were determined. Strict sensitivity means the correct set of markers in both images, whereas broader sensitivity means the correct set in at least one of the images. Sixteen of 100 malignancies were indicated by focal suspicious microcalcification clusters, 53 tumors by masses and 31 cases by both signs of breast cancer. The CAD evaluation was divided into only two different markers: one for microcalcifications and one for masses. Thus, 47 (16+31) tumor-induced microcalcifications and 84 (53+31) malignancy-related masses were checked using the CAD system.
Eighteen of 100 unilateral mammography examinations revealed identical patterns in all three scans (18% reproducibility). Eleven of 47 suspicious focal microcalcification clusters and 43/84 masses were correctly marked on both mammographic views in all three CAD scans (strict and broader sensitivity, 23.4 and 51.1%, respectively). Six of 47 microcalcification clusters and 8/84 masses were totally missed in all images by the system (false negative rate, 12.8 and 9.6%, respectively).
Reproducibility is essential for CAD systems. Currently, reproducibility of the used CAD system appears to be insufficient for clinical routine. Improvement of the system characteristics would make such systems valuable as a 'second reader' in clinical examination.
测试商用计算机辅助检测（CAD）系统在乳腺摄影胶片上标记的可重复性。
对100例经乳腺摄影检测出可疑病灶且经组织病理学证实为恶性的患者进行了100次单侧乳腺摄影检查（每次检查包括CC位和MLO位），采用CAD系统对这些检查进行回顾性扫描，共扫描三次。机构肿瘤病例样本库中每第五位患者纳入本研究。本研究仅纳入有一个可见病灶的病例。测定了可重复性和敏感性（严格意义和广义意义上）。严格敏感性是指两张图像中标记均正确，而广义敏感性是指至少一张图像中标记正确。100例恶性肿瘤中，16例由局灶性可疑微钙化簇提示，53例由肿块提示，31例由两种乳腺癌征象提示。CAD评估仅分为两种不同标记：一种用于微钙化，一种用于肿块。因此，使用CAD系统检查了47个（16 + 31）肿瘤诱导的微钙化和84个（53 + 31）与恶性肿瘤相关的肿块。
100次单侧乳腺摄影检查中有18次在所有三次扫描中显示出相同模式（可重复性为18%）。在所有三次CAD扫描中，47个可疑局灶性微钙化簇中有11个以及84个肿块中有43个在两张乳腺造影片上均被正确标记（严格敏感性和广义敏感性分别为23.4%和51.1%）。系统在所有图像中完全遗漏了47个微钙化簇中的6个以及84个肿块中的8个（假阴性率分别为12.8%和9.6%）。
可重复性对CAD系统至关重要。目前，所用CAD系统的可重复性在临床常规应用中似乎不足。系统特性的改善将使此类系统在临床检查中作为“第二阅片者”具有价值。
