Diffusion Weighted Imaging

Moving beyond single-shot echo planar imaging for diffusion weighted imaging in the prostate.

Traditionally, diffusion weighted imaging (DWI) has been accomplished utilizing single-shot echo planar imaging (SS-EPI) techniques. The long echo trains in SS-EPI lead to geometric and pile-up artifacts in the settings of main magnetic field inhomogeneities. DWI is a critical component of prostate MRI exams, but SS-EPI in prostate imaging often suffers due to field inhomogenieties caused by rectal gas and metal implants such as hip replacements. As such, we are working on moving beyond SS-EPI for prostate DWI. One pathway we are exploring is the incorporation of multi-shot echo planar imaging techniques to decrease the length of the EPI echo train and thereby reducing the sensitivity to field inhomogeneity artifacts. Another pathway we are investigating is replacing EPI based DWI, with a diffusion-prepped sequence utilizing a 3D fast spin echo readout that largely removes the issues of field inhomogeneity.