[Diagnosis of infraclinical lesions of the breast with dynamic MRI: results of a prospective and multicenter study].

AIM

To determine the accuracy of dynamic contrast-enhanced subfraction MRI to diagnose nonpalpable breast lesions in a prospective multicenter study.

MATERIAL AND METHODS

From June to November 1994, 72 patients had a surgical biopsy for a nonpalpable breast lesion and a preoperative dynamic MR after an informed consent was obtained. MR examinations were performed on 0.5, 1 and 1.5T MR unit. Each center underwent dynamic sequences either in spin or gradient echo in T1 weighted images obtained in less than two minutes before and after injection of Gadolinium-DOTA. The presence/absence of contrast enhancement within two minutes after injection of Gadolinium were considered as positive/negative findings respectively.

RESULTS

These 72 women had mammographic (n = 80) or ultrasonographic lesions (n = 2). Mammograms showed mass (n = 23), asymmetrical density (n = 2), architectural distorsion (n = 8), clustered microcalcifications (n = 47) or was normal (n = 2). Dynamic Breast MR imaging showed early contrast enhancement in 44 malignant lesions (sensitivity: 89.8%) and 13 benign lesions (specificity: 60.6%). Five intraductal carcinoma of comedo (n = 1) or non-comedo (n = 4) type did not demonstrate any early contrast enhancement.

CONCLUSION

This prospective mulcentric study confirms the high sensitivity of dynamic breast MRI whatever the type of MR unit or sequences.