MR ductography: comparison with conventional ductography as a diagnostic method in patients with nipple discharge.

Nipple discharge is a common symptom that mostly results from benign conditions. The most significant cause is carcinoma, which accounts for 1%-45% of cases. Therefore, identification of intraductal lesions is important. Conventional ductography, the recommended method of identifying lesions, is invasive and has inherent limitations. Magnetic resonance (MR) ductography is performed with heavily T2-weighted sequences; it is noninvasive and requires neither radiation nor contrast media. Like conventional ductography, MR ductography shows the dilated ducts as tubular structures with high signal intensity. Intraductal lesions appear as a signal defect, duct wall irregularity, or ductal obstruction. No specific conventional ductographic or MR ductographic finding allows differentiation between benign and malignant disease, and neither technique can demonstrate the extent of disease. MR mammography with intravenous injection of contrast material reveals the extent of disease, and a dynamic study may help distinguish between malignant and benign lesions. Fusion imaging with MR ductography and MR mammography demonstrates not only the presence of an intraductal abnormality but also the extent of the lesion on one image, thus clearly showing the relationship between the dilated duct and the intraductal lesion. Copyright RSNA, 2007.