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

被引:124
作者
Sun, Phillip Zhe
Zhou, Jinyuan
Huang, Judy
van Zijl, Peter
机构
[1] Johns Hopkins Univ, Sch Med, Dept Neurosurg, Baltimore, MD 21205 USA
[2] Johns Hopkins Univ, Sch Med, Russell H Morgan Dept Radiol & Radiol Sci, Baltimore, MD 21205 USA
[3] FM Kirby Res Ctr Funct Brain Imaging, Kennedy Krieger Inst, Baltimore, MD USA
关键词
acute ischemia; APT; CEST; magnetization transfer; stroke;
D O I
10.1002/mrm.21151
中图分类号
R8 [特种医学]; R445 [影像诊断学];
学科分类号
1002 ; 100207 ; 1009 ;
摘要
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 (PWC) 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 mu T for our particular coil setup, and a maximally obtainable APT ratio difference of 2.9% +/- 0.3% between ischemic and normal brain regions.
引用
收藏
页码:405 / 410
页数:6
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