title: A quantitative MRI method for imaging blood-brain barrier leakage in experimental traumatic brain injury.
abstract: Blood-brain barrier (BBB) disruption is common following traumatic brain injury (TBI). Dynamic contrast enhanced (DCE) MRI can longitudinally measure the transport coefficient Ktrans which reflects BBB permeability. Ktrans measurements however are not widely used in TBI research because it is generally considered to be noisy and possesses low spatial resolution. We improved spatiotemporal resolution and signal sensitivity of Ktrans MRI in rats by using a high-sensitivity surface transceiver coil. To overcome the signal drop off profile of the surface coil, a pre-scan module was used to map the flip angle (B1 field) and magnetization (M0) distributions. A series of T1-weighted gradient echo images were acquired and fitted to the extended Kety model with reversible or irreversible leakage, and the best model was selected using F-statistics. We applied this method to study the rat brain one hour following controlled cortical impact (mild to moderate TBI), and observed clear depiction of the BBB damage around the impact regions, which matched that outlined by Evans Blue extravasation. Unlike the relatively uniform T2 contrast showing cerebral edema, Ktrans shows a pronounced heterogeneous spatial profile in and around the impact regions, displaying a nonlinear relationship with T2. This improved Ktrans MRI method is also compatible with the use of high-sensitivity surface coil and the high-contrast two-coil arterial spin-labeling method for cerebral blood flow measurement, enabling more comprehensive investigation of the pathophysiology in TBI.
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America; Department of Ophthalmology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Justin Alexander
authors.initials: JA
authors.lastname: Long
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America; Department of Cellular and Structure Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America; Department of Neurology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Lora Talley
authors.initials: LT
authors.lastname: Watts
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Li
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America; Department of Ophthalmology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America; Department of Neurology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America; South Texas Veterans Health Care System, Department of Veterans Affairs, San Antonio, Texas, United States of America.
authors.forename: Timothy Q
authors.initials: TQ
authors.lastname: Duong
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001929:Brain Edema / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001930:Brain Injuries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003287:Contrast Media; D006801:Humans; D008279:Magnetic Resonance Imaging; D011859:Radiography; D051381:Rats
chemical_list: D003287:Contrast Media