title: Correlation of early reduction in the apparent diffusion coefficient of water with blood flow reduction during middle cerebral artery occlusion in rats.
abstract: To determine the relationship between reductions in the apparent diffusion coefficient of water (ADC) and in cerebral blood flow (CBF) during focal ischemia, we used diffusion-weighted magnetic resonance (D-MR) imaging and autoradiographic CBF analysis to examine rats subjected to 30 or 90 min of permanent middle cerebral artery (MCA) occlusion. In the 30-min occlusion group (n = 10), the area with substantially reduced ADC (15% or more below the contralateral level [ADC15]) corresponded best to the area with CBF below 25 ml/100 g/min and was significantly smaller than the area with CBF below 50 ml/100 g/min (CBF50), a level associated with reduced protein synthesis and delayed necrosis (40 +/- 13% versus 74 +/- 8% of the ischemic hemisphere; P < 0.0001). In the 90-min occlusion group (n = 6), the ADC15 area corresponded best to the CBF30 to CBF35 area and was again significantly smaller than the CBF50 area (54 +/- 13% versus 73 +/- 20%, P < 0.05). Thus, the area of substantially reduced ADC at 30 and 90 min represents only 53% and 74%, respectively, of the tissue at risk for infarction. These findings indicate a potential limitation in using early D-MR imaging to predict stroke outcome.
authors.affiliation: Department of Neurological Surgery, Veterans Administration Medical Center, San Francisco, CA 94121, USA.
authors.forename: A
authors.initials: A
authors.lastname: Mancuso
authors.forename: H
authors.initials: H
authors.lastname: Karibe
authors.forename: W D
authors.initials: WD
authors.lastname: Rooney
authors.forename: G J
authors.initials: GJ
authors.lastname: Zarow
authors.forename: S H
authors.initials: SH
authors.lastname: Graham
authors.forename: M W
authors.initials: MW
authors.lastname: Weiner
authors.forename: P R
authors.initials: PR
authors.lastname: Weinstein
mesh_terms: D000818:Animals; D001345:Autoradiography; D001834:Body Water / Q000502:physiology*; D002536:Cerebral Arteries / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003250:Constriction; D004058:Diffusion; D002546:Ischemic Attack, Transient / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley