A novel continuous arterial spin labeling approach for CBF measurement in rats.pdf

Magn Reson Mater Phy (2009) 22:135–142 DOI 10.1007/s10334-008-0157-8 RESEARCH ARTICLE A novel continuous arterial spin labeling approach for CBF measurement in rats with reduced labeling time and optimized signal-to-noise ratio efficiency Yuguang Meng · Hao Lei Received: 21 February 2008 / Revised: 12 November 2008 / Accepted: 12 November 2008 / Published online: 5 December 2008 ? ESMRMB 2008 Abstract Objective To develop a continuous arterial spin labeling (CASL) perfusion imaging method for cerebral blood flow (CBF)measurement in ratswith reduced spin-labeling length and optimized signal-to-noise ratio (SNR f ) per unit time. Materials and methods In the proposed method, the longi- tudinal magnetization of brain tissue water in the imaging slice is prepared into a proper state before spin-labeling, and a post-tagging delay is employed after spin-labeling. The method was implemented on a 4.7T small animal scanner. Numerical simulations and in vivo experiments were used to evaluate the performance of the method proposed. Results With the proposed method, absolute CBF could be measured accurately from normal rat with a spin-labeling pulse as short as 400ms, and yet employing the same formula as that used in the conventional CASL perfusion imaging method for calculation. The method also showed improved SNR f per unit time over the conventional CASL perfusion imaging method and the pulsed arterial spin labeling perfu- sion imaging method FAIR. Conclusion Compared to the conventional CASL perfusion imaging method, the proposed method would be advanta- geous for CBF measurement in small animals having short vascular transit time in terms of SNR f per unit time and other benefits brought by shortened spin-labeling pulse. Y. Meng · H. Lei (B) State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, 30# Xiaohongshan, 430071 Wuhan, Hubei, People’s Republic of China e-mail: leihao@wip