Over the last few years there has been dramatic advances in using various MRI's in detecting PC, locating the tumor and sizing it and also identifying extra capsular extension and lymph node cancers.
The following paper by Dr Barentsz, one of the top MRI radiologists in the world, gives a good description of the latest techniques and thier accuracy in spotting PC. The more accurate the initial staging, the more favorable the outcome.
www.prostate-cancer.org/education/Localdis/Barentsz_MRI_in_PC
JohnT