DYNAMIC 3-D MR MAMMOGRAPHY USING A RAPID GRADIENT-ECHO SEQUENCE

Up to now, MR mammography is performed by two different methods: 2-D t echniques with high temporal resolution and 3-D techniques with high s patial resolution. This article investigates whether a dynamic examina tion of the breast using a novel 3-D-gradient-echo sequence is feasibl e with sufficient spatial and temporal resolution. MR imaging was perf ormed on a 1.0 Tesla imager using a gradient field strength of 15 mT/m . Phantom measurements were done to evaluate the correlation between s ignal intensity and contrast medium concentration for different sequen ces. Subsequently, 40 patients with 22 histologically verified lesions were examined using the double breast coil and a novel FLASH3D sequen ce (T-R/T-E/fa 9/3/50 degrees). Reading of the films in standardized d ocumentation, multiplanar reconstruction (MPR), calculation and maximu m intensity projection (MIP) of subtraction images as well as signal-t o-time curve calculations in selected ROIs were performed for data eva luation. In the phantom measurements the FLASH3D-9/3/50 degrees sequen ce yielded the best correlation between signal intensity and Gd-DTPA c oncentration. The sequence provided good visualization even of small l esions. The 3-D postprocessing procedures facilitated the detection an d localization of the lesions. Therefore, the new FLASH3D-9/3/50 degre es sequence enables a dynamic 3-D examination of the breast with a suf ficient spatial and temporal resolution.