MRI is generally useful in detecting prostate cancer, even early stage prostate cancer that is confined to the tegument, which generally appears as a low signal nodule in the normal high signal surrounding area. For the few prostate cancers that start in the metastatic and central regions, it has a signal intensity similar to that of the surrounding normal tissue, and it may be difficult to detect these tumors at this time. In the progressive stage of prostate cancer, the continuity of the prostatic tegument may be disrupted and the low signal mass may protrude into the fatty tissue surrounding the prostate.