THE DUCTAL CARCINOMA IN-SITU IN CONTRAST-ENHANCED DYNAMIC MR MAMMOGRAPHY - MORPHOLOGY AND SIGNAL ENHANCEMENT

Purpose: The detectability with magnetic resonance mammography (MR-M) of non-invasive ductal carcinoma in situ (DCIS), its morphology, and p atterns of contrast enhancement were studied. Material and methods: A total of 849 MR-M examinations were performed in 741 patients using a dynamic, contrast-enhanced FLASH 3D sequence at 1.0 T. Surgical breast biopsies were obtained in 332 cases. Histological work-up confirmed 1 64 carcinomas, including 20 DCIS. Results: Of 20 DCIS, 14 were correct ly diagnosed by MR-M on the basis of focal increase of signal intensit y. In two cases (10%), no increase of signal intensity was observed. I n another three cases (15%), multifocal enhancement lead to a false-ne gative diagnosis. In one case (5%), DCIS was a random finding in a pat ient diagnosed and treated for adjacent phylloides tumour. The sensiti vity of MR-M was 70%. 4 (20%) of the DCIS did not show microcalcificat ions at conventional mammography and were only detected at MR-M. The s ensitivity of conventional mammography also amounted to 70%. However, the combination of both imaging methods increased sensitivity to 90%. Conclusion: Ductal carcinoma in situ is not reliably detectable by MR- mammography alone due to lack of a uniform pattern of enhancement.