Radiology, Vol 135, 747-750, Copyright © 1980 by Radiological Society of North America
The ultrastructural basis of periventricular edema: preliminary studies
AE James Jr, WJ Flor, GR Novak, JL Ribas, JL Parker and WL Sickel
The pathophysiology of periventricular lucency (PVL) on CT in primates was
evaluated by transmission (TEM) and scanning electron microscopy (SEM). At
100 days after Silastic-induced hydrocephalus, six primate brains showed
loss of cilia and ependymal cells over the ventricular surface and abnormal
small supraependymal cells. TEM demonstrated communicating pathways between
the ventricular lumen and brain parenchyma and the extracellular space was
markedly increased. At 1000 days, ependymal changes in two brains were
noted at greater distances from the ventricular angle. This study suggests
that CT periventricular lucency in patients with hydrocephalus is due to
the increased extracellular space. The lack of recognition of PVL by
computed tomography in chronic normal pressure hydrocephalus may be due to
change in distribution and resolution limits.
