Winning Abstracts from the 2010 Medical Student Abstract Competition: Ultrasound And MRI In Fetuses With Ventriculomegaly: Can Cortical Development Be Used To Predict Postnatal Outcome?
Author: Yi Li, Harvard Medical School, Class of 2011
Introduction:
Fetal ventriculomegaly (VM) is a condition where the fetal cerebral
ventricles are dilated to greater than or equal to 10mm at the
level of the atrium of the lateral ventricles. Our study aimed to
assess the visualization of cortical maturation by ultrasound (US)
and fetal MRI in fetuses referred for VM, and to investigate
whether sulcal visualization can be used to predict postnatal
developmental outcomes in fetuses with VM. We hypothesized that
delays in ultrasound and MR visualization of sulci with respect to
gestational age will correlate with cognitive and motor
developmental delays in fetuses with VM.
Methods:
318 fetuses referred for VM, with gestational age (GA) ranging from
15.7 to 42 weeks (average 26.3±5.9 weeks), were scanned by
US and MRI. Four to six radiologists rated the visualization of the
interhemispheric, sylvian, calcarine, parieto-occipital, cingulate,
central, superior temporal, precentral, postcentral, inferior
temporal, inferior frontal, insular, parietal, secondary temporal,
secondary frontal, secondary parietal, superior occipital, inferior
occipital, and tertiary frontal sulci by US and MR imaging.
Majority opinion on sulcal visualization was compared amongst
fetuses categorize by central nervous system (CNS) abnormality:
normal, isolated VM, and VM with additional CNS abnormalities.
Infants received postnatal neurodevelopmental testing at 6 months,
1 year, and 2 years of age and were categorized into normal
development, mild developmental delays, and severe developmental
delays. ANOVA was used to assess for correlations amongst
gestational age, ventricular size, delays in sulcal visualization,
and postnatal developmental outcome.
Results:
Sulci were visualized more frequently and at an earlier gestational
ages by MR than by US. Sulcal visualization in fetuses with
isolated VM lagged slightly behind visualization in normal fetuses;
however, this difference was not statistically significant for most
of the sulci. Sulcal visualization in fetuses with both VM and
other CNS anomalies lagged significantly behind visualization in
normal fetuses and fetuses with mild VM for virtually all sulci. In
fetuses with isolated VM, delays in sulcal visualization did not
correlate with live birth or with developmental outcome after
adjusting for ventricular size.
Conclusion:
Visualization of sulci is dependent on the imaging modality and the
GA at which the fetus is imaged. There are minor lags in sulcal
visualization for fetuses with isolated VM, but these do not
correlate with postnatal neurodevelopmental outcome.