A comparative MR and pathological study on fetal CNS disorders

Object: We used MR after sonography to help us in prenatal counseling in 58 complicated pregnancies from 1998 to 2000. Methods: All fetal MR examinations were undertaken with a 1.5-T magnet usin g a body-phased-array coil and an ultrafast imaging technique, half-Fourier sin-le-shot turbo spin-echo (HASTE). Twelve fetuses were found to have maj or anomalies, and in each of these cases either delivery was induced or the pregnancy was terminated. In 6 of the fetuses, with anomalies of the centr al nervous system, postmortem examinations were then performed after they f ailed to survive, and these constitute the patient sample investigated in t he current study. The fetal gestational ages in these 6 cases ranged from 2 4 to 32 weeks. MR imaging demonstrated morphological details of the anomali es. They were: alobar holoprosencephaly in 2, middle interhemispheric fusio n in 1, alobar holoprosencephaly with Dandy-Walker malformations in 1, a Da ndy-Walker variant in 1 and twin-twin transfusion syndrome with hypoxic-isc hemic injury to the brain in 1. Conclusions: Postmortem examinations confirmed the MR diagnoses, and these observations support us in improving our understanding of the pathogenesis of fetal CNS anomalies.