Chemical exchange saturation transfer

Chemical exchange saturation transfer (CEST) imaging is a novel molecular MR technique that enables imaging certain compounds at concentrations that are too low to impact the contrast of standard MR imaging and too low to directly be detected in MRS at typical water imaging resolution .

Amide proton transfer (APT) is the most studied type of CEST imaging .
APT has been used successfully for imaging of protein content and pH, the latter being possible due to the strong dependence of the amide proton exchange rate on pH . APT is showing promise clinically, especially for characterizing brain tumors and distinguishing recurrent tumor from treatment effects .