Evaluation of fat saturation technique for T2-weighted endorectal coil MRI of the prostate.

The use of fat suppression has been found to improve tissue contrast and artifact control for performance of body coil MR imaging of the pelvis. The objective of this study was to evaluate whether use of fat suppression confers similar advantages when endorectal coil MR examinations are performed for staging of prostate cancer. Sixty consecutive patients were evaluated with conventional T1-weighted (TR 600, TE 20) and conventional and fat saturation proton density-/T2-weighted (TR 2500, TE 35/80) sequences. Thirteen of 60 patients underwent subsequent radical prostatectomy and constituted the study group for which conventional and fat suppressed long TR images were directly compared by three reviewers. Criteria assessed included the relative ability of each sequence to demonstrate zonal distinction, periprostatic venous plexus, fibromuscular stroma, capsule definition, seminal vesicle architecture, tumor conspicuity, capsular penetration and/or seminal vesicle tumor invasion, artifact control, and overall image quality. There was no statistically significant improvement in factors relating to image quality with use of fat saturation. In addition, depiction of the anatomic and pathologic features listed above was not significantly improved for fat-suppressed as compared with conventional endorectal coil images. It is concluded that fat saturation does not result in significant improvement over conventional T2-weighted images in endorectal MR imaging of the prostate.