Form the Departments of Radiology (A.C.P., A.I.J., S.K.P., C.H.N., M.N., H.P.C., M.A.H., K.E.M.) and Biostatistics (T.M.), University of Michigan Health System, 1500 E Medical Center Dr, Med Inn Building C414, Ann Arbor, MI 48109.
Radiology. 2020 Dec;297(3):534-542. doi: 10.1148/radiol.2020192805. Epub 2020 Oct 6.
Background Digital breast tomosynthesis (DBT) helps reduce recall rates and improve cancer detection compared with two-dimensional (2D) mammography but has a longer interpretation time. Purpose To evaluate the effect of DBT slab thickness and overlap on reader performance and interpretation time in the absence of 1-mm slices. Materials and Methods In this retrospective HIPAA-compliant multireader study of DBT examinations performed between August 2013 and July 2017, four fellowship-trained breast imaging radiologists blinded to final histologic findings interpreted DBT examinations by using a standard protocol (10-mm slabs with 5-mm overlap, 1-mm slices, synthetic 2D mammogram) and an experimental protocol (6-mm slabs with 3-mm overlap, synthetic 2D mammogram) with a crossover design. Among the 122 DBT examinations, 74 mammographic findings had final histologic findings, including 31 masses (26 malignant), 20 groups of calcifications (12 malignant), 18 architectural distortions (15 malignant), and five asymmetries (two malignant). Durations of reader interpretations were recorded. Comparisons were made by using receiver operating characteristic curves for diagnostic performance and paired tests for continuous variables. Results Among 122 women, mean age was 58.6 years ± 10.1 (standard deviation). For detection of malignancy, areas under the receiver operating characteristic curves were similar between protocols (range, 0.83-0.94 vs 0.84-0.92; ≥ .63). Mean DBT interpretation time was shorter with the experimental protocol for three of four readers (reader 1, 5.6 minutes ± 1.7 vs 4.7 minutes ± 1.4 [ < .001]; reader 2, 2.8 minutes ± 1.1 vs 2.3 minutes ± 1.0 [ = .001]; reader 3, 3.6 minutes ± 1.4 vs 3.3 minutes ± 1.3 [ = .17]; reader 4, 4.3 minutes ± 1.0 vs 3.8 minutes ± 1.1 [ ≤ .001]), with 72% reduction in both mean number of images and mean file size ( < .001 for both). Conclusion A digital breast tomosynthesis reconstruction protocol that uses 6-mm slabs with 3-mm overlap, without 1-mm slices, had similar diagnostic performance compared with the standard protocol and led to a reduced interpretation time for three of four readers. © RSNA, 2020 See also the editorial by Chang in this issue.
背景 与二维（2D）乳房 X 线摄影相比，数字乳腺断层合成术（DBT）有助于降低召回率并提高癌症检出率，但解读时间更长。目的 在没有 1 毫米切片的情况下，评估 DBT 平板厚度和重叠对读者表现和解读时间的影响。材料与方法 本研究为回顾性 HIPAA 合规性多读者研究，纳入 2013 年 8 月至 2017 年 7 月间进行的 DBT 检查，4 名接受过乳房成像放射学奖学金培训的读者使用标准方案（10 毫米平板，5 毫米重叠，1 毫米切片，合成 2D 乳房 X 线摄影）和实验方案（6 毫米平板，3 毫米重叠，合成 2D 乳房 X 线摄影）进行 DBT 检查，两种方案均采用交叉设计。在 122 次 DBT 检查中，74 次乳腺检查结果有最终的组织学发现，包括 31 个肿块（26 个恶性）、20 个钙化组（12 个恶性）、18 个结构扭曲（15 个恶性）和 5 个不对称（2 个恶性）。记录读者解读的持续时间。使用诊断性能的受试者工作特征曲线和连续变量的配对 t 检验进行比较。结果 在 122 名女性中，平均年龄为 58.6 岁±10.1（标准差）。对于恶性肿瘤的检测，两种方案的受试者工作特征曲线下面积相似（范围，0.83-0.94 与 0.84-0.92；≥0.63）。对于四位读者中的三位，使用实验方案的 DBT 解读时间更短（读者 1，5.6 分钟±1.7 与 4.7 分钟±1.4[<0.001]；读者 2，2.8 分钟±1.1 与 2.3 分钟±1.0[=0.001]；读者 3，3.6 分钟±1.4 与 3.3 分钟±1.3[=0.17]；读者 4，4.3 分钟±1.0 与 3.8 分钟±1.1[≤0.001]），平均图像数量和平均文件大小均减少 72%（两者均<0.001）。结论 与标准方案相比，使用无 1 毫米切片的 6 毫米平板，3 毫米重叠的数字乳腺断层合成术重建方案具有相似的诊断性能，并使四位读者中的三位的解读时间缩短。
