title: MRI mapping of cerebrovascular reactivity via gas inhalation challenges.
abstract: The brain is a spatially heterogeneous and temporally dynamic organ, with different regions requiring different amount of blood supply at different time. Therefore, the ability of the blood vessels to dilate or constrict, known as Cerebral-Vascular-Reactivity (CVR), represents an important domain of vascular function. An imaging marker representing this dynamic property will provide new information of cerebral vessels under normal and diseased conditions such as stroke, dementia, atherosclerosis, small vessel diseases, brain tumor, traumatic brain injury, and multiple sclerosis. In order to perform this type of measurement in humans, it is necessary to deliver a vasoactive stimulus such as CO2 and/or O2 gas mixture while quantitative brain magnetic resonance images (MRI) are being collected. In this work, we presented a MR compatible gas-delivery system and the associated protocol that allow the delivery of special gas mixtures (e.g., O2, CO2, N2, and their combinations) while the subject is lying inside the MRI scanner. This system is relatively simple, economical, and easy to use, and the experimental protocol allows accurate mapping of CVR in both healthy volunteers and patients with neurological disorders. This approach has the potential to be used in broad clinical applications and in better understanding of brain vascular pathophysiology. In the video, we demonstrate how to set up the system inside an MRI suite and how to perform a complete experiment on a human participant.
authors.affiliation: Advanced Imaging Research Center, University of Texas Southwestern Medical Center; hanzhang.lu@utsouthwestern.edu.
authors.forename: Hanzhang
authors.initials: H
authors.lastname: Lu
authors.affiliation: Advanced Imaging Research Center, University of Texas Southwestern Medical Center.
authors.forename: Peiying
authors.initials: P
authors.lastname: Liu
authors.affiliation: Advanced Imaging Research Center, University of Texas Southwestern Medical Center.
authors.forename: Uma
authors.initials: U
authors.lastname: Yezhuvath
authors.affiliation: Advanced Imaging Research Center, University of Texas Southwestern Medical Center.
authors.forename: Yamei
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine.
authors.forename: Olga
authors.initials: O
authors.lastname: Marshall
authors.affiliation: Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Ge
mesh_terms: D000280:Administration, Inhalation; D001921:Brain / Q000098:blood supply*; D001931:Brain Mapping / Q000379:methods*; D002245:Carbon Dioxide / Q000008:administration & dosage; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009584:Nitrogen / Q000008:administration & dosage; D010100:Oxygen / Q000008:administration & dosage; D014662:Vasoconstrictor Agents / Q000008:administration & dosage; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen