title: Spatiotemporal changes in blood-brain barrier permeability, cerebral blood flow, T2 and diffusion following mild traumatic brain injury.
abstract: The blood-brain barrier (BBB) can be impaired following traumatic brain injury (TBI), however the spatiotemporal dynamics of BBB leakage remain incompletely understood. In this study, we evaluated the spatiotemporal evolution of BBB permeability using dynamic contrast-enhanced MRI and measured the volume transfer coefficient (K(trans)), a quantitative measure of contrast agent leakage across the blood and extravascular compartment. Measurements were made in a controlled cortical impact (CCI) model of mild TBI in rats from 1h to 7 days following TBI. The results were compared with cerebral blood flow, T2 and diffusion MRI from the same animal. Spatially, K(trans) changes were localized to superficial cortical layers within a 1mm thickness, which was dramatically different from the changes in cerebral blood flow, T2 and diffusion, which were localized to not only the superficial layers but also to brain regions up to 2.2mm from the cortical surface. Temporally, K(trans) changes peaked at day 3, similar to CBF and ADC changes, but differed from T2 and FA, whose changes peaked on day 2. The pattern of superficial cortical layer localization of K(trans) was consistent with patterns revealed by Evans Blue extravasation. Collectively, these results suggest that BBB disruption, edema formation, blood flow disturbance and diffusion changes are related to different components of the mechanical impact, and may play different roles in determining injury progression and tissue fate processes following TBI.
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, TX 78229, USA; Department of Ophthalmology, University of Texas Health Science Center at San Antonio, TX 78229, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, TX 78229, USA; Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA; Department of Neurology, University of Texas Health Science Center at San Antonio, TX 78229, USA.
authors.forename: Lora
authors.initials: L
authors.lastname: Watts
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, TX 78229, USA.
authors.forename: Justin
authors.initials: J
authors.lastname: Long
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, TX 78229, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, TX 78229, USA.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, TX 78229, USA.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, TX 78229, USA.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Li
authors.affiliation: Research Imaging Institute, University of Texas Health Science Center at San Antonio, TX 78229, USA; Department of Ophthalmology, University of Texas Health Science Center at San Antonio, TX 78229, USA. Electronic address: duongt@uthscsa.edu.
authors.forename: Timothy Q
authors.initials: TQ
authors.lastname: Duong
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology*; D001924:Brain Concussion / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology*; D001929:Brain Edema / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D002199:Capillary Permeability; D002540:Cerebral Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D003287:Contrast Media
keywords: BBB permeability; Diffusion MRI; Dynamic contrast enhanced MRI; Edema; Traumatic brain injury