The Influence of Design and Position of the Labeling Coil on the Efficiency in CASL Experiments at 7 T a Computer Simulation

Robert Trampel¹, Mikhail Kozlov¹, Thies Jochimsen¹, Enrico Reimer¹, Toralf Mildner¹, Robert Turner¹

Because of the increased signal-to-noise ratio and the prolonged T₁ time of arterial blood perfusion measurements at 7 T are expected to be more sensitive. However, especially at such high field strengths the profile of the <B>B</B>₁⁺ field produced by the labeling coil depends strongly on the coil design. This and the position of the coil may influence the efficiency α of the adiabatic spin inversion. A numerical method for predicting α is demonstrated considering the <B>B</B>₁⁺ profile at the position of labeling as simulated using the HFSS software package. A wide range of parameters resulted in sufficient inversion efficiencies.