Morphometric estimation of brain swelling and atrophy.

A morphometric method was presented to estimate brain swelling or atrophy from the geometric characteristics of the pontine cross section. The ratio of the area (A) to the perimeter squared (L2) was termed "area factor" (f) and used as a factor indicating circularity. Normal standards for the net cross-sectional area (Ap) and the area factor (f) of the pons measured on paraffin sections were 3.43 approximately 4.87 cm2 and 0.0684 approximately 0.0740, respectively. Values exceeding these ranges suggested brain edema. The pontine area factors (f) of the control cases under 60 years of age were less spread out than Ap, whereas they exhibited larger individual variations over that age presumably as a result of varying involution of the brain. A close correlation was found between Ap and water content of the cerebral white matter, except in pontine hemorrhage. The correlation was particularly marked in the group of cerebral diseases other than stroke. The longitudinal length of the basis pontis (lp) was essentially the same in the normal brain and even in the stoke group excluding pontine and cerebellar hemorrhage. In severe brain swelling the pontine longitudinal length was rather reduced.