Vitaliy Khlebnikov1, Nicolas Geades2, Dennis WJ Klomp1, Hans Hoogduin1, Penny Gowland2, and Olivier Mougin2
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, Nottingham, United Kingdom
Chemical Exchange Saturation Transfer (CEST) has gained much popularity due to its unmatched sensitivity to dilute labile protons when compared to other MRI techniques. Of particular interest are two CEST effects: Amide Proton Transfer (APT, CEST of amides) and Nuclear Overhauser Enhancement (NOE). Fast-paced developments for CEST resulted in the design of multiple CEST imaging sequences. This raises the obvious question as to which sequence to use and in what particular applications. Two pulsed volumetric CEST acquisition schemes are currently available in the literature. The first is based on the standard Magnetization Transfer imaging technique: a steady-state (SS) acquisition with alternating brief saturation and image acquisition. The second is based on the preparation of the magnetization before a long readout, where the prolonged saturation reaches a pseudo-steady state (PS) before the image acquisition. In this report, these two CEST acquisition schemes, optimized for maximum sensitivity to APT and NOE effects through Bloch-McConnell simulations, were systematically compared for the same spatial resolution, brain coverage and scan time.
