A quantitative MRI method for imaging blood-brain barrier leakage in experimental traumatic brain injury

• Published in: PloS one Vol. 9; no. 12; p. e114173
• Main Authors: Li, Wei, Long, Justin Alexander, Watts, Lora Talley, Jiang, Zhao, Shen, Qiang, Li, Yunxia, Duong, Timothy Q
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 05.12.2014; Public Library of Science (PLoS)
• Subjects: Animals; Biology and Life Sciences; Blood flow; Blood-brain barrier; Blood-Brain Barrier - diagnostic imaging; Blood-Brain Barrier - physiopathology; Brain; Brain Edema - diagnostic imaging; Brain Edema - physiopathology; Brain injuries; Brain Injuries - diagnostic imaging; Brain Injuries - physiopathology; Cerebral blood flow; Contrast Media; Cortex; Edema; Extravasation; Flow measurement; Head injuries; Humans; Image acquisition; Impact damage; Leakage; Magnetic Resonance Imaging; Magnetization; Membrane permeability; Methods; Neuroimaging; Permeability; Radiography; Rats; Research and Analysis Methods; Sensitivity; Spatial discrimination; Spatial resolution; Spin labeling; Transceivers; Traumatic brain injury; United States > US; Texas
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0114173

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.