Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University.
Institute of Biomedical Sciences, Tokushima University Graduate School.
Magn Reson Med Sci. 2018 Jan 10;17(1):86-94. doi: 10.2463/mrms.tn.2016-0069. Epub 2017 May 31.
The chemical exchange saturation transfer (CEST) effect on an egg white (EW) suspension was investigated for optimization of magnetization transfer (MT) power (B) and pH dependency with the addition of lactic acid. Applying a higher MT pulse, B, Z-spectrum shows higher asymmetry and the magnetisation transfer ratio (MTR) signal increases to around 1-3.5 ppm, indicating a higher CEST effect. Amide proton transfer (APT) at 3.5 ppm shows a signal elevation in MTR with the application of higher B power and high pH. In addition, the hydroxyl proton signal in MTR increases as pH is reduced by lactic acid. In Z-spectrum of B at 1.0 μT and 2.0 μT, the dependence on CEST effect of amide proton and hydroxyl proton could be observed by using an EW suspension phantom. The CEST MT power was optimized on the EW suspension phantom with pH dependency and further confirmed on volunteers. In addition, APT imaging at 3.5 ppm using B at 1.0 μT performed on two human brains with different pathophysiological conditions indicated appropriate ATP effect.
研究了蛋清 (EW) 悬浮液的化学交换饱和转移 (CEST) 效应，以优化外加乳酸条件下的磁化转移 (MT) 功率 (B) 和 pH 值依赖性。应用更高的 MT 脉冲，B 值的 Z 谱显示出更高的不对称性，磁化转移比 (MTR) 信号增加到约 1-3.5 ppm，表明 CEST 效应更高。在应用更高的 B 功率和高 pH 值时，3.5 ppm 处的酰胺质子转移 (APT) 在 MTR 中显示出信号升高。此外，随着乳酸降低 pH 值，MTR 中的羟基质子信号增加。在 B 值为 1.0 μT 和 2.0 μT 的 Z 谱中，可以通过 EW 悬浮液模型观察到酰胺质子和羟基质子的 CEST MT 功率对 pH 值的依赖性，并在志愿者中进一步得到证实。此外，在具有不同病理生理条件的两个人脑上使用 B 值为 1.0 μT 进行的 3.5 ppm APT 成像表明具有适当的 ATP 效应。
