Optimization of pulse train presaturation for CEST imaging in clinical scanners

摘要: Chemical exchange saturation transfer (CEST) imaging depends on the performance of radiofrequency during experiment. Scanner specifications, in particular limited pulse width and duty-cycle, specific absorption rate guidelines restrict full exploitation CEST effects clinical MR systems. The purpose this study was to optimize techniques for effective train presaturation a whole-body scanner. Theoretical analysis simulations spectral properties trains demonstrated significance τP interpulse delay τD selective labeling chemically exchanging proton pool. experiments with model solutions, e.g., creatine dissolved water, showed best = 100 msec, regarding minimum direct water z-spectra distinct magnetization ratio asymmetry that can be determined quantitatively. Saturation efficiency Gaussian-shaped pulses using timing evaluated imagers field strengths 1.5, 3, 7 T. proposed does not require hardware modifications, offers low rate, used standard setup. Magn Reson Med, 2011. © 2011 Wiley-Liss, Inc.