The assessment of the biometric parameters with fetal MR imaging in fetuses with mild-isolated ventriculomegaly

Abstract

Objective: To evaluate the biometric parameters of fetal brain in mild-isolated ventriculomegaly (VM) by using fetal brain magnetic resonance (MR) imaging.Materials and methods: In this retrospective study, we reviewed the fetal brain biometry in 36 fetuses with mild-isolated VM and 34 fetuses who had no central nervous system abnormality by using MR imaging. All of the images were interpreted by two radiologists. The evaluated parameters of both groups were tegmento-vermian angle, anteroposterior and superoinferior diameter of vermis, length of the corpus callosum, fronto-occipital diameter, laterolateral diameter of the cerebellum, cerebral and calvarial biparietal diameter, width of interhemispheric distance, third ventricle, and cisterna magna. Results: The mean gestational age was not significantly different between the normal group and mild-isolated VM group 24.73 (SD ± 0.60) and 24.52 (SD ± 0.64), respectively (p=0.595). No statistically significant difference was found in biometric parameters between the groups (p > 0.05). The anteroposterior and superoinferior diameter of the vermis, length of the corpus callosum, fronto-occipital diameter, cerebellar laterolateral diameter, cerebral and calvarial biparietal diameter increased and tegmento-vermian angle decreased with gestational age. Interhemispheric distance and third ventricle diameter were stable in both groups, and the width of cisterna magna also was stable in the normal group, while tended to be increased in the mild-isolated VM group. Conclusion: Intracranial anatomy should be evaluated carefully in fetuses with VM to rule out associated abnormalities although no differences in biometric values between normal and isolated VM groups in our study. Further studies are required to reach more accurate results.