Coronal measurement of the fetal lateral ventricles: comparison between ultrasonography and magnetic resonance imaging

Objective Cerebral ventricular atrial diameter is routinely measured on fetal ultrasound examination and magnetic resonance imaging (MRI); however, the methods have not been compared prospectively. The aim of this study was to evaluate the agreement between fetal ultrasonograpby and MRI in the measurement of atrial diameter on a coronal slice. Materials and methods Measurements of both lateral ventricles were Performed Prospectively in 106 fetuses using ultrasonography and MRI on the same day. In 39 of these fetuses, MRI was performed following the detection of ventriculomegaly on ultrasound examination. The median gestational age was 32 weeks. The following factors were recorded: the fetal position, the ventricular location (deep or superficial) and the ultrasound approach (transfontanellar or not). The measurements were performed on a coronal slice at the level of the choroid plexuses using both techniques. Results The two techniques yielded results in close agreement, independently of the three factors noted above. Ventricular atrial diameters below 10 mm tended to be slightly overestimated by ultrasonograpby, whereas those above 10 mm tended to be underestimated in comparison to measurements by MRI. Conclusions Coronal measurements of the atrial diameter of both cerebral ventricles, whether deep or superficial, are similar when obtained by ultrasonograpby and MRI. This agreement does not appear to be influenced by the position of the fetal bead or by the ultrasound approach (transfontanellar or otherwise) used. Copyright (c) 2005 ISUOG. Published by John Wiley & Sons, Ltd.