P30.03: Value of fetal magnetic resonance imaging in fetuses diagnosed prenatally with CNS abnormalities in ultrasound

Abstract

We evaluated whether fetal magnetic resonance imaging (MRI) could provide useful clinical information to diagnose the CNS abnormalities prenatally and assessed whether fetal MRI could affect the obstetric counseling with the parents or the plan of management. A retrospective study of all cases of prenatally detected CNS abnormalities was performed in 20 patients in Kangnam St. Mary's Hospital, the Catholic University of Korea, from May 2002 to December 2006. Associated abnormalities, pregnancy outcome and infant follow-up were recorded. Indications of fetal MRI included Dandy walker malformation (n = 4), ventriculomegaly combined with additional CNS anomaly (n = 3), megacisterna magna (n = 3), macrocephaly (n = 3), isolated ventriculomegaly (n = 2), arachnoid cyst (n = 2), agenesis of corpus callosum (n = 1), arnold-chiari malformation (n = 1), and spinal open neural tube defect (n = 1). The results of MRI were in agreement with ultrasound in 13 cases. Among those MRI provided more additional information in eight cases, incorrect diagnosis in one case with ventriculomegaly which was proven to be an agenesis of corpus callosum. In one case with Arnold-chiari malformation, ultrasound provided more clinical information than MRI. MRI changed the diagnosis in seven cases. Among those there was an error in the diagnosis of one fetus with isolated marked ventriculomegaly, which had been diagnosed as an ACC. Five parents decided to terminate their pregnancies because of ACC, Dandy-walker malformation, severe ventriculomegaly, Arnold-chiari malformation, and meningomyelocele. Fetal MRI is a useful complementary examination when prenatal ultrasound is inadequate or doubtful. MRI is also valuable in the evaluation of the fetal anatomy for planning delivery and management.