Assessing Diagnostic Performance Using the Transverse Plane Plus Coronal Plane Compared With the Transverse Plane Alone in Screening Automated Breast Ultrasound

Objectives The coronal plane is the unique display mode of automated breast (AB) ultrasound (US), which has valuable features of showing the entire breast anatomy and providing additional diagnostic value for breast lesions. However, whether adding the coronal plane could improve the diagnostic performance in screening breast cancer remains uncertain. This study aimed to evaluate the value of adding the coronal plane in interpretation for AB US screening. Methods In this retrospective study, AB US images from 644 women (396 in the no‐finding group, 143 with benign lesions, and 105 with malignant lesions) aged 40–70 years were collected between January 2016 and October 2020. Four novice radiologists (with 1–5 years of experience with breast US) and four experienced radiologists (with >5 years of experience with breast US) were assigned to read all AB US images in the transverse plane plus coronal plane (T + C planes) and transverse plane (T plane) alone in separate reading sessions. Diagnostic performance, lesion conspicuity, and reading time were compared using analysis of variance. Results The mean reading time of all radiologists was significantly shorter in the T + C planes reading mode than in the T plane alone (115 ± 32 vs 128 ± 31 s, respectively; P < .05), and cancers had a higher conspicuity (odds ratio, 1.76; 95% confidence interval [CI], 1.00–3.08; P = .04). No significant differences were noted in the two reading modes (T + C planes vs T plane) in the sensitivity (82% [95% CI, 74–89%] vs 81% [95% CI, 74–88%], respectively; P = .68) and specificity (68% [95% CI, 62–75%] vs 70% [95% CI, 64–75%], respectively; P = .39) when Breast Imaging‐Reporting and Data System (BI‐RADS) 3 was set as the threshold. There were also no significant differences in the two reading modes (T + C planes vs T plane) in the sensitivity (70% [95% CI, 64–76%] vs 69% [95% CI, 63–75%], respectively; P = .39) and specificity (91% [95% CI, 87–96%] vs 91% [95% CI, 88–95%], respectively; P = .90) when BI‐RADS 4 was set as the threshold. In addition, the mean areas under the receiver operating characteristic curves of all radiologists in the two reading modes (T + C planes vs T plane) were not significantly different (0.84 [95% CI, 0.79–0.89] vs 0.83 [95% CI, 0.78–0.89], respectively; P = .61). Conclusions Adding a coronal plane in the AB US screening setting saved the reading time and improved the conspicuity of breast cancers but not the diagnostic performance.