Development of Efficient Dynamic Magnetic Resonance Imaging Methods with Application to Breast Cancer Detection and Diagnosis

Abstract : This fellowship research project focuses on improving the temporal and spatial resolution in dynamic contrast-enhanced magnetic resonance imaging (MRI) of the breast. Dynamic contrast-enhanced MRI has been investigated as a possible means for non- invasive determination of the benign or malignant status of a breast tumor due to the differential rate of enhancement following injection of a contrast agent (1-9). In order to capitalize on the time of greatest differentiation between malignant and benign lesions, a sequence of images of the breast must be acquired during the first 1 or 2 minutes following contrast injection (10,11), leading to a requirement for high temporal resolution. In addition, high spatial resolution in 3 dimensions is imperative to allow the visualization of very small tumors with complete coverage of the breast. High signal-to-noise ratio (SNR) is necessary so that noise does not interfere with the differentiation between the malignant and benign enhancement rates. However, with conventional MRI techniques, since each of the dynamic images is collected independently, the requirements for increasing the temporal and spatial resolutions are conflicting. For example, if N encodings are collected for each image where TR is the time to collect one encoding and Ak is the spatial frequency step between encodings, the spatial resolution will be N1Ak' but the temporal resolution will be limited to NTR which may not be acceptable for large N.