Microvascular Perfusion Based on Arterial Spin Labeled Perfusion MRI as a Measure of Vascular Risk in Alzheimer's Disease

Issue title: Physiopathology of Vascular Risk Factors in Alzheimer's Disease

Guest editors: Jack de la Torre

Article type: Research Article

Authors: Zhang, Quan^{a; e} | Stafford, Randall B.^{a; b} | Wang, Ze^{a; d} | Arnold, Steven E.^{b; d} | Wolk, David A.^{a; b} | Detre, John A.^{a; b; c; *}

Affiliations: [a] Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, PA, USA | [b] Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA | [c] Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA | [d] Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA | [e] Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China

Correspondence: [*] Correspondence to: John A. Detre, MD, Department of Radiology, University of Pennsylvania, 3 West Gates Building, 3400 Spruce Street, Philadelphia, PA 19041-4283, USA. Tel.: +1 215 349 8465; Fax: +1 215 614 1927; E-mail: detre@mail.med.upenn.edu.

Abstract: There is growing recognition of an interaction between cerebrovascular disease and Alzheimer's disease, but the mechanisms of this interaction remain poorly understood. While macroscopic stroke can clearly produce cognitive deficits and accelerate Alzheimer's disease, the prevalence and implications of microvascular disease in Alzheimer's disease pathogenesis has been harder to define. At present, white matter (WM) lesions, primarily defined as hyperintensities seen on T2-weighted magnetic resonance imaging (MRI), provide the best biomarker of cerebrovascular disease at the microvascular level. However, T2 hyperintensities in WM can also be caused by other mechanisms such as inflammation. Arterial spin labeled (ASL) perfusion MRI provides a noninvasive approach for quantifying cerebral blood flow (CBF). We explored CBF measurements with ASL in AD patients, mild cognitive impairment patients, and an age-matched control group to determine if CBF in gray matter or WM could be correlated with WM lesions, or to stratify patients by microvascular disease severity. In a retrospective sample, we were able to obtain credible measures of WM CBF using ASL MRI and observed trends suggesting that WM CBF may provide a useful biomarker of microvascular disease. Future prospective studies in larger cohorts with optimized ASL MRI protocols will be needed to validate these observations.

Keywords: Alzheimer's disease, arterial spin labeling, cerebral blood flow, magnetic resonance imaging, perfusion, vascular cognitive impairment, white matter lesions

DOI: 10.3233/JAD-2012-120964

Journal: Journal of Alzheimer's Disease, vol. 32, no. 3, pp. 677-687, 2012