Detection of microcalcifications in women with dense breasts and hypoechoic focal lesions: comparison of mammography and ultrasound

Purpose: Microcalcifications in the breasts can point to breast cancer. However, there is great morphologic variety, and microcalcifications do not always correlate with malignancy. We conducted a prospective study to compare ultrasound and mammography in the detection of microcalcifications following sonographic diagnosis of a hypoechoic focal lesion in women with dense breast composition.

Materials and methods: A total of 104 lesions potentially associated with microcalcifications (82 malignant and 23 benign lesions) were included in the study. The breast was examined by ultrasound (9 MHz, Aplio XG/500) with additional use of MicroPure imaging for the demonstration and evaluation of microcalcifications. The presence of a focal lesion was verified and microcalcifications were counted at ultrasound and mammography by blinded readers. The sensitivity and specificity were determined, and ROC analysis and AUC analysis were performed.

Results: The women had a median age of 51 years. The average number of microcalcifications detected by sonography (2.12 ± 2.77) and mammography (3.59 ± 6.35) was not significantly different (p > 0.05). Correlation of the techniques was adequate (Pearson's r = 0.616, p < 0.0001; Spearman's rho = 0.654, p < 0.0001). The intraclass correlation coefficient was K = 0.382 ± 0.072 (p < 0.0001), also indicating adequate agreement of both techniques. The sensitivity and specificity were 70%/30% for MicroPure and 45%/55% for mammography. The positive predictive value of mammography was superior to that of MicroPure (88% vs. 78%).

Conclusion: The sonographic detection of microcalcifications with MicroPure imaging in breasts with a hypoechoic focal lesion correlates well with digital mammography.