Morphologic basis of MR imaging of benign prostatic hyperplasia.

Fifteen prostates were obtained from patients autopsied at The Johns Hopkins Hospital and imaged fresh in vitro by high resolution magnetic resonance (MR) imaging with a surface coil. Following scanning, the specimens were fixed and sectioned in the same plane as the MR images. The prostate sections, corresponding to the MR images, were examined grossly and histologically for prostate pathology. Tissue characteristics were quantified by morphometric techniques and correlated with MR image intensity. Five prostates were normal and showed two distinct anatomic zones, a central periurethral zone and a peripheral zone. These two zones corresponded to two zones identified on MR of the five normal prostates. In contrast, both the MR images and the pathologic and morphometric studies of nine of the 10 prostates with benign prostatic hyperplasia (BPH) showed three distinct zones: a central region of BPH, a surrounding fibrous capsule, and a peripheral zone. This study suggests that there is a morphologic basis for MR intensity in the prostate.