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OBJECT Recently, concern has been raised that hyperventilation following severe traumatic brain injury (TBI) could lead to cerebral ischemia. In acute ischemic stroke, in which the baseline metabolic rate is normal, reduction in cerebral blood flow (CBF) below a threshold of 18 to 20 ml/100 g/min is associated with energy failure. In severe TBI, however,(More)
Stenosis or occlusion of the major arteries of the head and neck may cause hemodynamic impairment of the distal cerebral circulation. Hemodynamic factors may play an important role in the pathogenesis of ischemic stroke for patients with cerebrovascular disease. Several neuroimaging methods are currently available for the indirect assessment of the(More)
To test the hypothesis that regional cerebral blood flow (rCBF) is normally regulated by regional metabolic activity, rCBF and the regional cerebral metabolic rate for oxygen (rCMRO2) were compared in selected human subjects. In normal subjects and patients with chronic, stable diseases of brain, rCBF correlated well with rCMRO2. In one individual with mild(More)
The presence or degree of haemodynamic impairment due to occlusive cerebrovascular disease is often inferred from measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), oxygen extraction fraction (OEF) and the cerebral rate for oxygen metabolism (CMRO2). However, the relationship of these variables, in particular CBV, to regional cerebral(More)
We conducted a multi-stage, genome-wide association study of bladder cancer with a primary scan of 591,637 SNPs in 3,532 affected individuals (cases) and 5,120 controls of European descent from five studies followed by a replication strategy, which included 8,382 cases and 48,275 controls from 16 studies. In a combined analysis, we identified three new(More)
Regional cerebral blood flow (rCBF) and regional cerebral metabolic rate of oxygen (rCMRO2) were measured by positron emission tomography (PET) in four patients with subarachnoid hemorrhage and hemiparesis due to cerebral vasospasm. With resolution of the vasospasm, two patients recovered and two remained hemiparetic. Contralateral to the hemiparesis, rCBF(More)
The technique of positron emission tomography was used to measure cerebral blood volume (CBV) in 10 normal right-handed human volunteers following inhalation of trace quantities of cyclotron-produced, 11C-labeled carbon monoxide. In scans obtained 4 cm above the orbitomeatal line, CBV was 4.3 ml per 100 gm of tissue, whereas in scans obtained 8 cm above the(More)
Positron emission tomography (PET) was used to investigate the regional hemodynamic and metabolic changes that accompany focal reductions in cerebral blood flow to ischemic but uninfarcted regions of the brain. Studies were performed on 7 patients chosen from a larger group of subjects with transient ischemic attacks and normal computed tomographic(More)
The St. Louis Carotid Occlusion Study demonstrated that ipsilateral increased O2 extraction fraction (OEF) (Stage II hemodynamic failure) measured by positron emission tomography (PET) is a powerful independent risk factor for subsequent stroke in patients with symptomatic complete carotid artery (CA) occlusion. The ipsilateral ischemic stroke rate at 2(More)
Emission computed tomography (CT) is a nuclear medicine visualization technique that yields an image of the distribution of a previously administered radionuclide in any desired transverse section of the body. Emission CT allows the safe, quantitative, three-dimensional measurement of regional radionuclide distribution in tissue. This approach is analogous(More)