title: A comparison study between the saturation-recovery-T1and CASL MRI methods for quantitative CBF imaging.
abstract: The saturation-recovery (SR)-T1MRI method for quantitatively imaging cerebral blood flow (CBF) change (ΔCBF) concurrently with the blood oxygenation level dependence (BOLD) alteration has been recently developed and validated by simultaneous measurement of relative CBF change using laser Doppler flowmetry (LDF) in rats at 9.4T. In this study, ΔCBF induced by mildly transient hypercapnia and measured by the SR-T1MRI method was rigorously compared with an established perfusion MRI method-continuous arterial spin labeling (CASL) approach in normal and preclinical middle cerebral artery occlusion (MCAo) rat models. The results show an excellent agreement between ΔCBF values measured with these two imaging methods. Moreover, the intrinsic longitudinal relaxation rate (R1int) was experimentally determined in vivo in normal rat brains at 9.4T by comparing two independent measures of the apparent longitudinal relaxation rate (R1app) and CBF measured by the CSAL approach across a wide range of perfusion. In turn, the R1intconstant can be employed to calculate the CBF value based on the R1appmeasurement in healthy brain. This comparison study validates the fundamental relationship for linking brain tissue water R1appand cerebral perfusion, demonstrates the feasibility of imaging and quantifying both CBF and its change using the SR-T1MRI method in vivo.
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA; Diagnostic Radiology Residency Program, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Zhu
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Afshin A
authors.initials: AA
authors.lastname: Divani
authors.affiliation: Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Murphy
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA. Electronic address: wei@cmrr.umn.edu.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D023421:Models, Animal; D010477:Perfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D013113:Spin Labels
chemical_list: D013113:Spin Labels
keywords: CASL MRI; Cerebral blood flow; Middle cerebral artery occlusion; Perfusion; Rat brain; Saturation-recovery-T(1) MRI