Simplified quantitative description of amide proton transfer (APT) imaging during acute ischemia.

TitleSimplified quantitative description of amide proton transfer (APT) imaging during acute ischemia.
Publication TypeJournal Article
Year of Publication2007
AuthorsSun PZ, Zhou J, Huang J, van Zijl P
JournalMagnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine
Volume57
Issue2
Pagination405-10
Date Published2007 Feb
Abstract

Amide proton transfer (APT) imaging employs the chemical exchange saturation transfer (CEST) mechanism to detect mobile endogenous proteins and peptides. It can be used to detect pH reduction during acute ischemia and thus provide complementary information to perfusion-weighted (PWI) and diffusion-weighted (DWI) imaging. However, the APT contrast depends strongly on the choice of imaging parameters, especially the radiofrequency (RF) saturation time and strength, which need to be optimized. In this work it is shown that even though at least three proton pools are present, the description of the APT process during acute ischemia can be greatly simplified by means of a dual two-pool model analysis. With this approach, the experimentally measured RF irradiation power dependence of the effect in the rat brain was well predicted. The results showed an optimal RF strength of 0.75 microT for our particular coil setup, and a maximally obtainable APT ratio difference of 2.9%+/-0.3% between ischemic and normal brain regions.

DOI10.1021/jo800879e
Alternate JournalMagn Reson Med