Presented at the Neonatal Society 2011 Autumn Meeting.
Kyriakopoulou V, Vatansever D, Allsop J, Rutherford M
Robert Steiner MRI Unit, Clinical Sciences Centre, Medical Research Council, Hammersmith Hospital, Imperial College London, London, UK
Background: Fetal ventriculomegaly is the most frequent CNS abnormality occurring in 1% of fetuses. The outcome of infants with prenatal isolated ventriculomegaly is variable and the reasons for this variability remain unknown. Our hypothesis is that fetal ventriculomegaly is a marker of altered brain development characterised by relative overgrowth. The main aim of the study is to characterise in detail the brain phenotype of the fetus with isolated ventriculomegaly and compare to fetuses with normal brain appearance. Ethical approval was granted by the Hammersmith Hospital Ethics Committee (ethics No. 97/H0707/105) and informed consent obtained from all pregnant women.
Methods: Fetal brain MRI was performed using a 1.5T scanner in 60 fetuses with normal brain development (mean age 29.5 weeks, age range 22.4-38.9 weeks, 30 males/30 females) and 66 isolated ventriculomegaly cases (age range 22-37.3 weeks, mean 29.7 weeks, 48 males/18 females). Volumetric analysis of the lateral ventricles, supratentorial brain tissue and cortex was performed on 3D reconstructed datasets.
Results: Fetuses with isolated ventriculomegaly had significantly larger lateral ventricle volumes (295%, p<0.0001) as expected. This is the first study to show that total brain tissue volume is 9% larger in fetuses with ventriculomegaly (p=0.00006) compared to normal controls. Cortical volumes were also significantly larger even when correcting for the increase in brain tissue volume (12.5%, p=0.049).
Conclusion: Our results indicate aberrant brain development in the presence of ventriculomegaly supporting the hypothesis of relative overgrowth.
Corresponding author: vk908@imperial.ac.uk