CEREBRAL HEMODYNAMICS AND METABOLISM OF SEVERE DIFFUSE BRAIN INJURY MEASURED BY PET

Cerebral hemodynamics and metabolism in three patients with severe dif fuse brain injury were measured 10 days after onset using PET. In this study, regional cerebral blood flow (rCBF), oxygen extraction fractio n (rOEF), cerebral blood volume (rCBV), cerebral metabolic rate for ox ygen (rCMRO2), cerebral metabolic rate for glucose (rCMRglc) and cereb ral metabolic ratio (rCMRO2/rCMRglc) were measured. The Glasgow Coma S cale scores on admission were 4, 5 and 5, respectively, and CT on admi ssion showed typical findings of diffuse brain injury. As a result, PE T revealed misery perfusion and hyperglycolysis in Patient 1 and match ing low perfusion and low glucose metabolism in Patients 2 and 3. Alth ough Patient 1 died, Patients 2 and 3 had good recoveries. We speculat e that a long-lasting anaerobic state, indicated by a high OEF value a nd low metabolic ratio, is an important undesirable factor related to the outcome.