Efficiency of flow-driven adiabatic spin inversion under realistic experimental conditions: A computer simulation

• Published in: Magnetic resonance in medicine Vol. 51; no. 6; pp. 1187 - 1193
• Main Authors: Trampel, Robert, Jochimsen, Thies H., Mildner, Toralf, Norris, David G., Möller, Harald E.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.06.2004
• Subjects: adiabatic inversion; arterial spin labeling; Bloch equations; Blood Flow Velocity; Carotid Arteries - physiology; Cerebrovascular Circulation; Computer Simulation; Magnetic Resonance Angiography - methods; Models, Cardiovascular; Myocardial Contraction; perfusion; surface coil
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.20080

Continuous arterial spin labeling (CASL) using adiabatic inversion is a widely used approach for perfusion imaging. For the quantification of perfusion, a reliable determination of the labeling efficiency is required. A numerical method for predicting the labeling efficiency in CASL experiments under various experimental conditions, including spin relaxation, is demonstrated. The approach is especially useful in the case of labeling at the carotid artery with a surface coil, as consideration of the experimental or theoretical profile of the B1 field is straightforward. Other effects that are also accounted for include deviations from a constant labeling gradient, and variations in the blood flow velocity due to the cardiac cycle. Assuming relevant experimental and physiological conditions, maximum inversion efficiencies of about 85% can be obtained. Magn Reson Med 51:1187–1193, 2004. © 2004 Wiley‐Liss, Inc.