Removing lipid artifacts in CEST imaging with a two-point turbo-spin-echo Dixon method

Motivation: Chemical Exchange Saturation Transfer (CEST) imaging has advanced by capturing molecular-level information of tissue metabolites. However, strong fat artifacts can affect the contrast of CEST signals. Goal(s): We aim to seek a fat suppression technique that maintains high image signal-to-noise efficiency. Approach: By combining TSE-CEST and flexible two-point Dixon methods, utilizing accurate multi-peak fat models, the obtained water-only images are used as CEST images. Results: Z-spectra and MTRasym of ROIs in the water-fat-Creatine phantoms and high-fat fraction regions near the human knee demonstrate that accurate fat suppression achieved in the CEST images. Impact: We proposed a two-point turbo-spin-echo Dixon technique, which utilizes TSE-CEST instead of the conventional gradient echo Dixon acquisition. Robust fat suppression was achieved in the phantoms and human knee by utilizing Dixon on the two images acquired for each offset.