The value of dynamic contrast enhanced breast MRI in mammographically detected BI-RADS 5 microcalcifications.

Aims: To evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (MRI) in the diagnosis of BI-RADS-5 type of microcalcifications of the breast, to compare the size of the microcalcification lesions using mammography (MG) and MRI, and to determine the value of MRI in surgery for microcalcifications. The study also determines the morphology of microcalcification lesions, assesses kinetic curves and compare MRI features of ductal carcinoma in situ (DCIS) for different histopathological grades.

Methods: Our group consisted of 32 patients with mammographically detected BI-RADS 5 microcalcifications. The MRI was done in this group of women which was later followed by stereotactic vaccum-assisted biopsy (SVAB). Surgery was performed on all patients with a biopsy that resulted in a diagnosis of breast cancer or atypical ductal hyperplasia (ADH).

Results: Of our group of 32 patients, there were 35 mammograhically detected microcalcification lesions, 32 DCIS, one ADH and two benign findings according to the final histology. The microcalcification lesions were larger using MRI than in MG in 10 women. We diagnosed DCIS multifocality in 6 women and bilateral carcinoma in one woman. As with kinetic curve assessment, we found in 67 % of DCIS a rapid rise, 27 % a moderate and in 6 % a slow initial rise. With the pattern of enhancement in the delayed phase, we found in 30 % of DCIS a washout pattern, 67 % a plateau and in 3 % a persistent pattern. Noted difference between high and low grade DCIS was confirmed.

Conclusions: MRI sensitivity in the detection of DCIS was 94 % in our group of patients and was the sole evidence for detection of multifocality and bilateral incidence of carcinoma. In 26 % of women the outcome of MRI was the most important for converting breast conserving surgery to mastectomy.