Normal adnexa uteri specimens: anatomic basis of MR imaging features.

PURPOSE: To elucidate the anatomic basis for the magnetic resonance (MR) imaging features of normal ovaries and fallopian tubes and causes for varied MR appearances.

MATERIALS AND METHODS: MR imaging of 24 surgical specimens of ovary and adnexa uteri in the fresh state from 15 patients was performed before histopathologic processing. T1-weighted spin-echo and T2-weighted fast spin-echo images were obtained. MR imaging findings related to the zonal anatomy of the ovary, functional cysts, and fallopian tubes were correlated with findings at histopathologic examination.

RESULTS: Ovaries in premenopausal women showed differentiation between the ovarian cortex and the ovarian medulla on T2-weighted images and in histopathologic sections. Ovaries in postmenopausal women were more homogeneous because of replacement of the medulla with stromal proliferation and corpora albicantia. Functional cysts of the ovary had low-signal-intensity rims on T2-weighted images, which corresponded to the theca and stromal reaction around the cyst. The signal intensity of normal fallopian tubes was intermediate on T2-weighted images and that of muscularis was low.

CONCLUSION: Typical patterns of MR appearance of the ovary and functional cysts correlate with the regional histopathologic anatomy of the ovary. T2-weighted imaging of the ovary revealed cyst walls, corpora lutea, and ovarian medulla.