Brain Temperature Measured Using Proton MR Spectroscopy Detects Cerebral Hemodynamic Impairment in Patients With Unilateral Chronic Major Cerebral Artery Steno-Occlusive Disease

Abstract

Background and Purpose-Brain temperature is determined by the balance between heat produced by cerebral energy turnover and heat removed by cerebral blood flow. The purpose of the present study was to investigate whether brain temperature measured noninvasively using proton MR spectroscopy can detect cerebral hemodynamic impairment in patients with unilateral chronic internal carotid or middle cerebral artery occlusive disease when compared with positron emission tomography. Methods-Brain temperature, cerebral blood flow, and metabolism were measured using proton MR spectroscopy and 15 O-positron emission tomography, respectively, in 21 normal subjects and 37 patients. Positron emission tomography images were coregistered with MR images and resliced automatically using image analysis software. Regions of interest placed in both cerebral hemispheres on MR images were automatically superimposed in these resliced positron emission tomography images. Results-A significant correlation was observed between brain temperature difference (affected hemisphere-contralateral hemisphere) and both cerebral blood volume and oxygen extraction fraction ratio (affected hemisphere/contralateral hemisphere; rϭ0. 607; Pϭ0.0004 and rϭ0.631; Pϭ0.0002). With abnormally elevated cerebral blood volume or oxygen extraction fraction ratio defined as higher than the mean ϩ2 SDs obtained from normal subjects, brain temperature difference provided 86% or 92% sensitivity and 87% or 84% specificity with 80% or 73% positive and 91% or 95% negative predictive values for detecting abnormally elevated cerebral blood volume or oxygen extraction fraction ratios, respectively. Conclusions-Brain temperature measured using proton MR spectroscopy can detect cerebral hemodynamic impairment in patients with unilateral chronic major cerebral artery steno-occlusive disease. (Stroke. 2009;40:3012-3016.)

Postoperative Changes in Cerebral Metabolites Associated with Cognitive Improvement and Impairment after Carotid Endarterectomy: A 3T Proton MR Spectroscopy Study

“…Second, the cerebral hemisphere ipsilateral to the ICA stenosis often exhibits brain atrophy even when massive cortical infarction is not detected on MR imaging in the cerebral hemisphere. 36 In that situation, the proportion of CSF occupying the region of interest for measurement of cerebral metabolites by using MR spectroscopy is higher, thereby reducing the accuracy of metabolic ratios measured by MR spectroscopy. 36 Finally, a single-voxel region of interest for measurement of metabolites was placed on the section through the centrum semiovale.…”

“…36 In that situation, the proportion of CSF occupying the region of interest for measurement of cerebral metabolites by using MR spectroscopy is higher, thereby reducing the accuracy of metabolic ratios measured by MR spectroscopy. 36 Finally, a single-voxel region of interest for measurement of metabolites was placed on the section through the centrum semiovale. The value in the single-voxel region of interest does not always reflect the metabolic condition in the whole cerebral hemisphere.…”

Relation between brain temperature and white matter damage in subacute carbon monoxide poisoning

“…In these results, the lower BT might reflect a remarkably low metabolism in the brain and the main regulation system for BT might be independent of that of body temperature. Furthermore, another previous study has reported a good significant correlation between BT and CMRO 2 in patients with chronic ischemia3. Considering the large discrepancy between the abnormal high BT and normal body temperature in previous studies, it is natural to think that the basic mechanism to regulate BT might be different from that for body temperature, at least when the brain is in an abnormal state like low perfusion, low metabolism, and/or hypoxia after strong damage like SAH, ischemia, and CO poisoning38212223.…”

“…High OEF defined as misery perfusion, which indicates CBF reduction and maintained CMRO 2 , was also identified by means of PET in the acute phase after CO exposure7. Various reports from patient studies suggested that high BT could be associated with abnormal cerebral perfusion and metabolism, such as misery perfusion1234. In fact, as seen in a previous report8, an abnormally high BT was observed in all patients with subacute CO-poisoning.…”

“…It has already been reported that BT elevation occurred in patients presenting abnormal cerebral hemodynamics such as acute stroke, chronic ischemia, and moyamoya disease234. Especially, patients who showed BT elevation commonly might have an accompanying condition called ‘misery perfusion’56.…”