Improved Evaluation of (Hyper-)CEST Images Using the Spectral Dimension

Jrg Dpfert¹, Christopher Witte¹, Martin Kunth¹, Michael Beyermann¹, Leif Schrder¹

Chemical Exchange Saturation Transfer (CEST) is typically quantified by subtracting an on resonant saturation image from an off resonant reference image. When performing single-shot Hyper-CEST imaging with low signal from dissolved xenon this approach has serious problems as the low SNR is further decreased by the image subtraction. Here, we propose two alternative methods based on least squares fitting and principal component analysis, which exploit the information of a series of CEST images with a range of different saturation frequencies. Both presented methods lead to a significant gain in SNR and strongly improve the visualization of the agents.