Gestational trophoblastic neoplasm of the uterus: MR assessment.

Magnetic resonance (MR) imaging characteristics of uterine gestational trophoblastic neoplasia were prospectively studied in nine women (aged 21-58 years). MR imaging was done at the time of initial clinical diagnosis, after each of the first two cycles of chemotherapy, and 6-9 months after initiation of chemotherapy. Sagittal and transverse MR images of the pelvis were generated with a 0.35-T superconducting magnet and the double spin-echo technique with short and long repetition times (TRs). The neoplasm distorted the MR appearance of uterine zonal structures (myometrium, endometrium, and junctional zone) and demonstrated hypervascular masses of heterogeneous signal intensity. Favorable response to chemotherapy was determined by a decrease in serum beta-subunit human chorionic gonadotropin (HCG) concentrations, and was accompanied by MR findings of regression of vascular abnormalities, development of intralesional hemorrhage, and return of normal appearance of uterine zones. The return of uterine zonal anatomy on MR images antedated definitive decrease in uterine volume. All eight patients imaged 6-9 months after initial imaging showed normal uterine volume and zonal anatomy.