P1–291: Simultaneous measurement of blood‐CSF and blood‐brain barrier permeability: A pilot 7T dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) study
Year: 2013
Type: article
Abstract: The blood-cerebrospinal fluid barrier at the choroid plexus (CP) works in concert with the blood-brain barrier to provide a stable microenvironment for proper brain function. While the pivotal role of the CP in maintaining normal cerebrospinal fluid composition is well established, it's influence on blood-brain barrier permeability remains poorly understood. We used DCE-MRI to quantify the in vivo rate of transepithelial water exchange (T ci -1) at the CP and the capillary permeability surface-area product of water (P w S) in the aging human brain. 2D inversion recovery (IR) tFLASH images were acquired on 5 subjects (74± 6 yrs; 3 female/2 male) using a Siemens 7T system. A 180 ° inversion pulse was applied over a 6 mm axial slice every 2.0 s and intensity read out 7 times (153 to 1739 ms). A gadoteridol (0.05 mmol/kg) bolus was injected after the 10th inversion pulse. Longitudinal relaxation rate constant, R 1, maps were constructed by evaluating the IR-turboFLASH signal intensity equation, assuming monoexponential IR and accounting for all delays and RF pulses. Full volume R 1 maps were also prepared at different times relative to gadoteridol administration by voxel-wise fitting of four consecutively acquired, variable inversion time (0, 300, 1800, 3200 ms) IR-MPRAGE image sets. Blood R 1 values were determined in the sagittal sinus. T ci -1 and P w S were determined by fitting R 1 changes after gadoteridol injection to a two-compartment tissue model that accounts for equilibrium water exchange. Regions of interest (ROI) were selected in bilateral centrum semiovale white matter, frontal and parietal cortex, and hippocampus. Mean (± SD) T ci -1 of the CP was 1.7 ± 1.8 s -1. P w S values ranged from 2.7 ± 1.1 (centrum semiovale) to 4.8 ± 2.0 mL g -1 min -1 (posterior cingulate). T ci -1 values showed a strong positive correlation (R= 0.84; P= 0.07) with P w S in the hippocampus. A moderate association in frontal cortex was also observed (R= 0.64). Our results suggest that water exchange processes at the CP may influence microvascular permeability, particularly in periventricular structures. If confirmed in a larger study, these findings would provide evidence for a role of the blood-cerebrospinal fluid barrier in the microvascular changes that accompany brain aging.
Source: Alzheimer s & Dementia
Institution: Oregon Health & Science University
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1991631183