Magnetic resonance imaging of brain tissue displacement and brain tissue water contents during progressive brain compression. An experimental study in dogs.

Continuous recording of vital physiologic parameters and magnetic resonance imaging (MRI) was performed during continuous expansion of extradural rubber balloons in spontaneously ventilated anesthetized dogs. Initial physiologic changes appeared when the pontine cistern was compressed while respiratory arrest was regularly paralleled by marked tentorial and tonsillar herniation. Local increase in brain tissue water progressed during brain compression and was most marked in white matter of the brain. This was related to the regional decrease in cerebral perfusion pressure. The correlation between the morphologic and physiologic course of events during brain compression has a predictive value.