PRENATAL-DIAGNOSIS OF FETAL CORPUS-CALLOSUM AGENESIS BY ULTRASONOGRAPHY AND MAGNETIC-RESONANCE-IMAGING

Corpus callosum agenesis (CCA) was evaluated by ultrasound examination and magnetic resonance imaging (MRI) in 14 cases. Ultrasonography was able to suspect CCA by indirect signs but a definitive diagnosis of C CA was achieved in only four cases. MRI was able to diagnose complete CCA in 13 cases and showed absence of the posterior portion of the cor pus callosum in one case. Additional neurological abnormalities includ ing heterotopia, gyration anomaly, asymmetry of the cerebral hemispher es, and Dandy-Walker variant were documented in five cases, as well as an ocular anomaly which was present in one case, by MRI examination. Prenatal counselling for fetal agenesis of the corpus callosum is diff icult as the prognosis is uncertain. The association with other cerebr al abnormalities increases the likelihood of a poor outcome and ultras onographic assessment of the fetal brain is limited. We found MRI to b e a safe and useful additional procedure to complement ultrasonographi c diagnosis or suspicion of CCA. (C) 1998 John Wiley & Sons, Ltd.