CT measurement of the normal ventricular system in premature infants.

In order to develop quantitative criteria for normal lateral ventricular dimensions, 70 cerebral computed tomographic scans of premature infants were reviewed and 31 normal scans were selected as suitable for establishing cerebroventricular indices. In 15 normal premature infants of less than 32 weeks gestational age the mean bifrontal index was 0.28 +/- 0.05, the mean bicaudate index 0.10 +/- 0.02, and the mean bioccipital index 0.19 +/- 0.05. In 16 normal premature infants of more than 32 weeks gestational age the mean bifrontal, bicaudate, and bioccipital indices were 0.26 +/- 0.06, 0.11 +/- 0.03, and 0.17 +/- 0.04, respectively. No statistically significant differences were found in the values of the indices between the two groups, which demonstrates the uniformity of the ventricular size in normal premature infants.