Objective: To evaluate the accuracy of BI-RADS mammogram reports in Songklanagarind Hospital.

Materials and methods: A retrospective study of 2,064 mammogram reports was conducted and these were compared to the matching pathological reports. The reports were issued between January and December, 2005.

Results: There were 828 mammograms for breast cancer screening and 1,236 cases for diagnosis of breast diseases. The negative mammogram group (Breast Imaging Reporting and Database System; BI-RADS 1-3) showed negative predictive values of 83.3-93.2% while the positive mammogram group (BI-RADS 4, 5) showed positive predictive values of 31.9% and 93.1%, respectively. There were 5 cases reported as BI-RADS 1, 2 but the pathological reports showed malignancy. We found the cases in this group had dense breast tissue which could explain the false negative results.

Conclusion: BI-RADS reporting in Songklanagarind Hospital has the same accuracy as other institutions. We should be careful of misdiagnoses due to dense breast tissue.

Key words: BI-RADS, breast cancer, mammogram, ultrasound