Normal ventricular size and ventriculo-hemispheric ratio in infants upto 6 months of age by cranial ultrasonography.

Fifty cases each of preterm (greater than 34 weeks), full term and one month to six months age (400 total) were subjected to cranial ultrasonography for determination of ventricular size and ventriculohemispheric ratio. Ventricular size steadily increased from 4.64 +/- 1.84 mm in preterm to 10.72 +/- 2.92 mm in six months old infant. Ventriculohemispheric ratio increased from 0.12 +/- 0.052 in preterm to 0.17 +/- 0.056 in three months of age. Then steady level was maintained at 0.17 +/- 0.064 upto six months of age.