Contrast-enhanced dynamic MR imaging of postmolar gestational trophoblastic disease.

Conventional spin-echo (SE) and contrast-enhanced dynamic MR imaging were performed on a 1.5 T superconductive unit for evaluation of myometrial lesions in postmolar gestational trophoblastic disease (GTD) in 10 women. MR imaging was done at the time of the initial examination (n = 10), during (n = 6), and after repeated courses of chemotherapy (n = 10). The T2-weighted SE image revealed an enlarged uterus (n = 7), disappearance of zonal anatomy (n = 6), and heterogeneous signal intensities (n = 8) with prominent flow voids (n = 7). However, these abnormalities remained after repeated courses of chemotherapy, when the S-beta-HCG level returned to the normal range. Myometrial lesions characteristically had marked enhancement with areas of unenhancement on dynamic MR images in patients with highly elevated S-beta-HCG. Areas of contrast enhancement correlated with changes in S-beta-HCG level. The enhancement was reduced with decrease in S-beta-HCG level after repeated courses of chemotherapy. Six of 8 masses seen on T2-weighted images proved to be active trophoblastic lesions and 2 masses proved to be hematoma or necrosis. In 2 patients, abnormal myometrial lesions were detected only on contrast-enhanced dynamic MR imaging. These preliminary data indicate that contrast-enhanced dynamic MR imaging more clearly demonstrates myometrial involvement of postmolar GTD than conventional SE imaging.