title: Assessing intracranial vascular compliance using dynamic arterial spin labeling.
abstract: Vascular compliance (VC) is an important marker for a number of cardiovascular diseases and dementia, which is typically assessed in the central and peripheral arteries indirectly by quantifying pulse wave velocity (PWV), and/or pulse pressure waveform. To date, very few methods are available for the quantification of intracranial VC. In the present study, a novel MRI technique for in-vivo assessment of intracranial VC was introduced, where dynamic arterial spin labeling (ASL) scans were synchronized with the systolic and diastolic phases of the cardiac cycle. VC is defined as the ratio of change in arterial cerebral blood volume (ΔCBV) and change in arterial pressure (ΔBP). Intracranial VC was assessed in different vascular components using the proposed dynamic ASL method. Our results show that VC mainly occurs in large arteries, and gradually decreases in small arteries and arterioles. The comparison of intracranial VC between young and elderly subjects shows that aging is accompanied by a reduction of intracranial VC, in good agreement with the literature. Furthermore, a positive association between intracranial VC and cerebral perfusion measured using pseudo-continuous ASL with 3D GRASE MRI was observed independent of aging effects, suggesting loss of VC is associated with a decline in perfusion. Finally, a significant positive correlation between intracranial and central (aortic arch) VC was observed using an ungated phase-contrast 1D projection PWV technique. The proposed dynamic ASL method offers a promising approach for assessing intracranial VC in a range of cardiovascular diseases and dementia.
authors.affiliation: Laboratory of FMRI Technology (LOFT), Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA. Electronic address: lryan737@gmail.com.
authors.forename: Lirong
authors.initials: L
authors.lastname: Yan
authors.affiliation: Department of Neurology, University of Southern California, Los Angeles, CA, USA.
authors.forename: Collin Y
authors.initials: CY
authors.lastname: Liu
authors.affiliation: Laboratory of FMRI Technology (LOFT), Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Robert X
authors.initials: RX
authors.lastname: Smith
authors.affiliation: Laboratory of FMRI Technology (LOFT), Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Mayank
authors.initials: M
authors.lastname: Jog
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Langham
authors.affiliation: Laboratory of FMRI Technology (LOFT), Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Kate
authors.initials: K
authors.lastname: Krasileva
authors.affiliation: Department of Radiology, Northwestern University, United States.
authors.forename: Yufen
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Neurology, University of Southern California, Los Angeles, CA, USA; Mary S. Easton Center for Alzheimer's Disease Research, University of California Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Ringman
authors.affiliation: Laboratory of FMRI Technology (LOFT), Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Danny J J
authors.initials: DJJ
authors.lastname: Wang
mesh_terms: D000328:Adult; D062186:Arterial Pressure; D001158:Arteries / Q000502:physiology; D001160:Arterioles / Q000502:physiology; D001921:Brain / Q000098:blood supply* / Q000502:physiology*; D003187:Compliance; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D063177:Pulse Wave Analysis; D013113:Spin Labels; D018924:Vascular Capacitance; D055815:Young Adult
chemical_list: D013113:Spin Labels
keywords: Aging; Cardiovascular diseases; Cerebral perfusion; Dynamic arterial spin labeling; Intracranial vascular compliance; Pulse wave velocity