To evaluate the d breast tissue coverage of cone-beam breast computed tomography (CBBCT) compared with conventional digital mammography.

CBBCT scans and digital mammography in 96 patients (141 breasts) over the age of 35 were prospectively assessed in the study. CBBCT scans were performed within 1 week after digital mammography. Superior, inferior, medial, lateral, posterior coverage of breast tissue in CBBCT and digital mammography were evaluated, respectively. It wasconsidered as positive if there was a breast coverage. McNemar test was used to assess differences in breast coverage between CBBCT and digital mammography.

Within all the 141 cases, digital mammography covers the superior aspects in 141 cases (100.0%), inferior aspects in 88 cases (62.4%), medial aspects in 52 cases (36.9%), lateral aspects in 60 cases (42.6%), and posterior aspects in 17 cases (12.0%). CBBCT covers the superior aspects in 136 cases (96.4%), the inferior aspects in 136 cases (96.4%), the medial aspects in 129 cases (91.5%), the lateral aspects in 129 cases (91.5%), and the posterior aspects in 129 cases (91.5%). CBBCT had statistically significant better coverage than digital mammography in the inferior, medial, lateral, and posterior aspects (χ² values were 42.48, 67.95, 60.05 and 108.08, respectively; all P values<0.01) regions. No statistically significant difference (χ² value=3.20,P=0.074) was found in the superior aspects.

CBBCT has better breast tissue coverage than conventional digital mammography, especially in posterior aspects of breast tissues.

Mammography; Cone beam computed tomography