CEST-Dixon MRI for Sensitive and Accurate Measurement of Amide Proton Transfer in Humans at 3T

Jochen Keupp¹, Holger Eggers¹

CEST-MRI based measurement of endogenous proteins using the amide proton transfer (APT) signal could find important clinical applications in oncology (tumor metabolism) and in neurology (ischemic acidosis). As APT-MRI is very sensitive to B₀ inhomogeneity, we propose to apply multi gradient-echo sequences and derive a B₀ map by the Dixon technique, as opposed to previously described methods like full CEST-spectra interpolation or separate water resonance mapping. Furthermore, technical limits for pulse lengths on clinical scanners are addressed and a saturation of 1 second is achieved (human head). Feasibility of APT-MRI within 6 minutes (SENSE R=3) is demonstrated in volunteers at 3T.