Adjustment of Saturation and Rotation Effects (AROSE) for CEST Imaging

Endogenous CEST signal usually has low specificity due to contamination from the magnetization transfer (MT) effect and from other labile protons with close Larmor frequencies. We propose to improve CEST signal specificity with AROSE which measures the difference between CEST signals acquired with similar average saturation power but largely different duty cycles (DC), e.g., a continuous wave or a high DC pulse train versus a low DC one. Simulation and creatine phantom studies showed that AROSE can improve the specificity of slow to intermediate exchanging CEST signals with relatively limited loss of sensitivity.