Fast Multislice Chemical Exchange Saturation Transfer (CEST) MRI with Dual-channel RF Irradiation

The aim of this study is to develop a technique for rapid multislice chemical exchange saturation transfer (CEST) imaging with dual-channel radiofrequency (RF) irradiation to reduce scan time and enhance CEST contrast. Conventional CEST MRI is implemented with a long RF irradiation module, followed by fast image acquisition to obtain a steady state CEST contrast. However, it typically requires a long preparation time while producing relatively small CEST contrast. A dual-channel RF irradiation scheme is proposed including a long dual-channel RF irradiation module that establishes a steady state CEST contrast and repetitive short dual-channel secondary RF irradiation modules to maintain the contrast. The proposed method is designed to reduce the preparation time to reach steady state CEST contrast and efficiently maintain the contrast throughout signal averages and multislice acquisition. The proposed method was validated on a creatine phantom, and exhibited 31.96% higher CEST contrast than the conventional method. The proposed method, a fast multislice CEST MRI sequence with dual-channel RF irradiation module, is a promising technique with significantly improved CEST contrast and reduced scan time.