Indirect 17O‐magnetic resonance imaging of cerebral blood flow in the rat

Open Access
Publisher Website
Google Scholar
Abstract
Proton T1ρ-dispersion MRI is demonstrated for indirect, in vivo detection of 17O in the brain. This technique, which may be readily implemented on any clinical MRI scanner, is applied towards high-resolution, quantitative mapping of cerebral blood flow (CBF) in the rat by monitoring the clearance of 17O-enriched water. Strategies are derived and employed for 1) quantitation of absolute H217O tracer concentration from a ratio of high- and low-frequency spin-locked T1ρ images, and 2) mapping CBF without having to transform the T1ρ signal to H217O tracer concentration. Absolute regional blood flow was mapped in a single 3-mm brain slice at an in-plane resolution of 0.4 × 0.8 mm within a 5-min tracer washout time; these data are consistent with the less localized CBF measurements reported in the literature. T1ρ-weighted imaging yields excellent signal-to-noise ratios, spatiotemporal resolution, and anatomical contrast for mapping CBF. Magn Reson Med 49:479–487, 2003.