Development of Multi-parametric, High Field Magnetic Resonance Imaging Techniques for Improved Characterization of Prostate Cancer

At 3T, issues such as the J-modulation changes for citrate resonance at higher field, more severe magnetic susceptibility induced magnetic field inhomogeneities, and increased chemical shift mis-registration make robust acquisition and analysis of multi-parametric prostate MR data challenging. In this work, 3T prostate MR coils were developed and MR imaging sequences were optimized for acquisition of high-resolution anatomical images of the prostate. A new MLEV-Point RESolved Spectroscopy (MLEV-PRESS) sequence was developed to allow acquisition of up-right citrate resonance at 3T. High resolution (0.157cc) MR spectroscopic imaging (MRSI) data were acquired at 3T and the theoretical 2-fold increase in SNR over 1.5T was demonstrated. To reduce the scan time of MRSI to allow acquisition of other MR modality during one clinical exam, a new, fast and robust MRSI acquisition utilizing flyback echo-planar readout trajectories was also developed. High quality data were demonstrated within half of the scan time required for conventional MRSI acquisition. For acquisition of prostate MR data based on movement of water and tissue micro-environment to reflect morphological changes in prostate cancer, single-shot fast spin-echo diffusion tensor imaging (SSFSE-DTI) sequence and magnetization prepared sequence with multi-slice spiral imaging for were optimized for prostate DTI and T2 relaxation parameter mapping. Significantly different diffusion and T2 relaxation parameters were observed in regions of prostate cancer as compared to normal prostate peripheral zone.