Ventricular measurement for neonatal cranial ultrasound used to detect ventricular dilatation

Ventricular measurements of cranial ultrasounds in preterm infants shown in the (A1, A2) coronal and (B1, B2) parasagittal plane.
(A1) The two measurements shown in the coronal plane are ventricular index (VI), defined as the distance between the falx (double-fold of dura mater that descends through the interhemispheric fissure in the midline of the brain to separate the cerebral hemispheres) and the anterior horn width (AHW), defined as the diagonal width of the anterior horn measured at its widest point in the coronal plane.
(A2) The measurement shown in the coronal plane is the frontotemporal horn ratio (FTHR) obtained by measuring the widest distance of the frontal horns (1), and temporal horns (3) and dividing the average of these measurements by twice the largest biparietal distance (2).
(B1, B2) In these two ultrasound examples, the thalamo-occipital distance (TOD), defined as the distance between the outermost point of the thalamus at its junction with the choroid plexus and the outermost part of the occipital horn in the parasagittal plane, is demonstrated by the two arrows. The second example demonstrates severe posthemorrhagic ventricular dilation.