title: Longitudinal MR imaging study in the prediction of ischemic susceptibility after cerebral hypoperfusion in rats: Influence of aging and hypertension.
abstract: Our previous study has shown that aging and hypertension may alter apparent diffusion coefficient (ADC) and cerebral blood flow (CBF) and increase ischemic susceptibility in the non-ischemic rat brain. The present study wishes to further investigate whether aging and hypertension may influence cerebral diffusion/perfusion and increase ischemic susceptibility in the ischemic brain. Brain magnetic resonance (MR) imaging was examined 1day before and 1 and 7days after bilateral common carotid artery occlusion. Young and middle-aged normotensive Wistar-Kyoto rats and young and middle-aged spontaneously hypertensive rats (SHRs) were studied. Infarction occurred mainly in the parietal cortex and was larger in middle-aged SHRs than the other three groups (P<0.05). In pre-operation, ADC was higher and CBF was lower in middle-aged/hypertensive rats than young/normotensive rats (P<0.05). The ADC was higher in the parietal cortex of the rats with infarction at 7days when compared to the rats without infarction [receiver operating characteristic curve (ROC), P=0.001; binary logistic regression (BLR), P=0.006]. However, there was no difference in the hippocampus and thalamus. At day 1 post-operation, CBF reduced and ADC/CBF ratio elevated significantly in the parietal cortex of the rats with infarction when compared to the rats without infarction (CBF: ROC, P=0.002; BLR, P=0.017. ADC/CBF ratio: ROC, P=0.001; BLR, P=0.018). Our results demonstrated that pre-operation ADC and post-operation CBF and ADC/CBF ratio can be used as good MR markers in the prediction of ischemic susceptibility after cerebral hypoperfusion.
authors.affiliation: Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: J-T
authors.initials: JT
authors.lastname: Lee
authors.affiliation: Department of Medical Imaging and Radiological Sciences and Healthy Aging Research Center, Chang Gung University, Taiwan.
authors.forename: H-L
authors.initials: HL
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, Chiayi Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taiwan.
authors.forename: J-T
authors.initials: JT
authors.lastname: Yang
authors.affiliation: Department of Neurosurgery, Taipei Medical University, Shuang Ho Hospital, Taiwan.
authors.forename: S-T
authors.initials: ST
authors.lastname: Yang
authors.affiliation: Clinical Informatics and Medical Statistics Research Center, Chang Gung University, Taiwan.
authors.forename: J-R
authors.initials: JR
authors.lastname: Lin
authors.affiliation: Stroke Section, Department of Neurology and Stroke Center, Chang Gung Memorial Hospital, Linkou Medical Center, Chang Gung University College of Medicine, Taiwan. Electronic address: thlee@adm.cgmh.org.tw.
authors.forename: T-H
authors.initials: TH
authors.lastname: Lee
mesh_terms: D000375:Aging; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D020520:Brain Infarction / Q000209:etiology; D002545:Brain Ischemia / Q000175:diagnosis*; D002560:Cerebrovascular Circulation / Q000235:genetics / Q000502:physiology*; D004195:Disease Models, Animal; D004198:Disease Susceptibility; D006339:Heart Rate / Q000502:physiology; D006973:Hypertension / Q000503:physiopathology*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
keywords: 2-VO; ADC; ANOVA; AUC; BLR; CBF; CCA; EPI; MR; ROI; SD; SHR; WKY; Wistar-Kyoto; aging; analysis of variance; apparent diffusion coefficient; area under the curve; binary logistic regression; carotid artery; cerebral blood flow; cerebral hypoperfusion; common carotid arteries; diffusion-weighted MRI; echo-planar imaging; hypertension; magnetic resonance; perfusion-weighted MRI; region of interest; spontaneously hypertensive rat; standard deviation; two-vessel occlusion