To evaluate digital breast tomosynthesis (DBT) in the diagnosis of architectural distortion (AD) lesions.

The imaging data of 112 female patients with 126 AD lesions detected by DBT and full-field digital mammography (FFDM) in the Department of Radiology, Shaanxi Provincial Cancer Hospital between August 2018 and October 2019 were collected for a retrospective study. χ² test was used to compare the detection rate of AD between FFDM and DBT. According to the ultrasound BI-RADS grading, the lesions were divided into two groups: ultrasound-related group(BI-RADS 4A and above) and unrelated group(BI-RADS 1-3). The pathological results and the proportion of malignant lesions were compared between two groups by χ² test.

Totally 80 AD lesions were detected by FFDM and 126 by DBT. The detection rate of AD by DBT was significantly higher than that by FFDM [100%(126/126) vs 63.5%(80/126), χ²=56.272, P<0.001]. Among the 126 AD lesions, 45 were malignant lesions, 40 were benign lesions and 41 were high-risk lesions. There was a significant difference in the pathological results between ultrasound-related group (82 lesions) and unrelated group (44 lesions) (χ²=20.502, P<0.001). The proportion of malignant lesions was 48.8% (40/82) in ultrasound-related group, 11.4% (5/44) in unrelated group, indicating a significant difference (χ²=17.461, P<0.001). Among the 46 AD lesions only detected by DBT, the pathological results presented a significant difference between ultrasound-related group (21 lesions) and unrelated group (25 lesions) (χ²=7.672, P=0.022), while there was no significant difference in the proportion of malignant lesions between two groups [33.3% (7/21) vs 12.0% (3/25), χ²=3.053, P=0.081].

The detection rate of AD by DBT was significantly higher than that by FFDM.The AD lesion of BI-RADS 4A and above on ultrasonography shows a higher probability of malignancy.