Olivier M. Girard1,2, Gopal Varma3, Samira Mchinda1,2, Valentin Prevost1,2, Arnaud Le Troter1,2, Stanislas Rapacchi1,2, Maxime Guye1,2, Jean-Philippe Ranjeva1,2, David C. Alsop3, and Guillaume Duhamel1,2
1CRMBM, UMR 7339 CNRS, Aix-Marseille University, Marseille, France, 2Pôle d'Imagerie Médicale, CEMEREM, APHM, Marseille, France, 3Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
Inhomogeneous
Magnetization Transfer (ihMT) has shown improved specificity for myelinated
tissue as compared to conventional MT. Recently, fundamental developments have
led to theoretical modeling of the ihMT effect. In this study forward modeling
of a steady-state ihMT gradient echo (GRE) sequence is used to guide
experimental optimization for various TRs, power levels and ihMT pulse-train
duration. An efficient RF-energy deposition scheme is demonstrated for
relatively long TRs, leading to ihMTRs as high as 15-17% and 10-12% in WM at
1.5T and 3T, respectively. This opens new perspectives for patient studies at
clinical field strength and ihMT implementation at higher field strength.