James Alastair Meakin1, 2, Peter Jezzard1
1FMRIB Centre, University of Oxford, Oxford, United Kingdom; 2Gray Institute for Radiation Oncology and Biology, University of Oxford, Oxford, United Kingdom
Inaccurate measurement of perfusion using VSASL can arise due to the sensitivity of the velocity selective preparation to eddy currents. In this study, three velocity selective preparations were evaluated: a Double Refocused Hyperbolic Secant, BIR-4 and a novel BIR-8 preparation. We show that eddy currents during the velocity selective preparation cause unwanted tagging of static tissue and an overestimation of perfusion in VSASL. We demonstrate through simulations and experiments in healthy volunteers that the BIR-8 preparation has the least sensitivity to eddy currents, providing more accurate VSASL perfusion measurements.
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