Objective: Evaluation of the diagnostic quality of high-resolution B-mode sonography for the detection of microcalcifications and calcification-associated focal findings in patients with BI-RADS lesions of subtype 4a.
Patients and methods: 40 patients underwent X-ray mammography and 13-MHz B-mode sonography. The following parameters were examined: with X-ray mammography: extent of microcalcification and visibility of associated focal areas; with ultrasound: sensitivity of microcalcification findings, quality of presentation, extent of microcalcification, visibility of associated focal areas and feasibility of ultrasound-assisted biopsy.
Results: X-ray mammography showed a mean extent of microcalcification of 28 8 21 mm. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) and accuracy of microcalcification-associated focal findings were 61.5, 57.9, 50, 45.8 and 47.5%. B-mode sonography achieved a sensitivity of 100%. Sonographically, the mean extent of microcalcification was 7 +/- 3 mm and thus significantly smaller (p < 0.01). Sensitivity, specificity, PPV, NPV and accuracy were 14.3, 84.2, 50, 47.1 and 47.5%. Ultrasound-assisted biopsy appeared feasible in 22 patients (55%).
Conclusion: High-frequency B-mode sonography allows a highly sensitive confirmation of microcalcifications in the case of BI-RADS 4a lesions and seems to allow ultrasound-assisted biopsy in about half the patients.