Junctional zone of the uterus: correlation of MR imaging and histologic examination of hysterectomy specimens.

High-resolution magnetic resonance (MR) images of 12 hysterectomy specimens were correlated with results of light microscopy, image analysis, and immunohistochemical studies to investigate the histologic counterpart of the low-signal-intensity band, or junctional zone (JZ), that surrounds the bright central uterine stripe. All specimens were imaged with a 1.5-T superconducting magnet within 21/2 hours (on average) after hysterectomy. Comparison of histologic findings with measurements obtained at MR imaging indicates that the JZ represents the innermost layer of the myometrium. A threefold increase in percentage of nuclear area was found in the JZ in comparison with the outer myometrium, reflecting an increase in both size and number of nuclei. No difference in distribution of common components of the extracellular space (collagen, laminin, and fibronectin) was found between the two layers.