TY - JOUR
T1 - Novel proton exchange rate MRI presents unique contrast in brains of ischemic stroke patients
AU - Wang, Zhenxiong
AU - Shaghaghi, Mehran
AU - Zhang, Shun
AU - Zhang, Guiling
AU - Zhou, Yiran
AU - Wu, Di
AU - Zhang, Zhuoli
AU - Zhu, Wenzhen
AU - Cai, Kejia
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (grant numbers 81570462 , 81730049 and 81801666 ), the NIH grants R21 EB023516 (Cai), R01 AG061114 (Tai&Cai), R21 AG053876 (Tai&Cai), the University of Illinois at Chicago Department of Radiology start-up funds (Cai).
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Background: To map and quantify the proton exchange rate (kex) of brain tissues using improved omega plots in ischemic stroke patients and to investigate whether kex can serve as a potential endogenous surrogate imaging biomarker for detecting the metabolic state and the pathologic changes due to ischemic stroke. New Method: Three sets of Z-spectra were acquired from seventeen ischemic stroke patients using a spin echo-echo planar imaging sequence with pre-saturation chemical exchange saturation transfer (CEST) pulse at B1 of 1.5, 2.5, and 3.5 μT, respectively. Pixel-wise kex was calculated from improved omega plot of water direct saturation (DS)-removed Z-spectral signals. Results: The derived kex maps can differentiate infarcts from contralateral normal brain tissues with significantly increased signal (893 ± 52 s-1 vs. 739 ± 34 s-1, P < 0.001). Comparison with Existing Method(s): The kex maps were found to be different from conventional contrasts from diffusion-weighted imaging (DWI), CEST, and semi-solid magnetization transfer (MT) MRI. In brief, kex MRI showed larger lesion areas than DWI with different degrees and different lesion contrast compared to CEST and MT. Conclusions: In this preliminary translational research, the kex MRI based on DS-removed omega plots has been demonstrated for in vivo imaging of clinical ischemic stroke patients. As a noninvasive and unique MRI contrast, kex MRI at 3 T may serve as a potential surrogate imaging biomarker for the metabolic changes of stroke and help for monitoring the evolution and the treatment of stroke.
AB - Background: To map and quantify the proton exchange rate (kex) of brain tissues using improved omega plots in ischemic stroke patients and to investigate whether kex can serve as a potential endogenous surrogate imaging biomarker for detecting the metabolic state and the pathologic changes due to ischemic stroke. New Method: Three sets of Z-spectra were acquired from seventeen ischemic stroke patients using a spin echo-echo planar imaging sequence with pre-saturation chemical exchange saturation transfer (CEST) pulse at B1 of 1.5, 2.5, and 3.5 μT, respectively. Pixel-wise kex was calculated from improved omega plot of water direct saturation (DS)-removed Z-spectral signals. Results: The derived kex maps can differentiate infarcts from contralateral normal brain tissues with significantly increased signal (893 ± 52 s-1 vs. 739 ± 34 s-1, P < 0.001). Comparison with Existing Method(s): The kex maps were found to be different from conventional contrasts from diffusion-weighted imaging (DWI), CEST, and semi-solid magnetization transfer (MT) MRI. In brief, kex MRI showed larger lesion areas than DWI with different degrees and different lesion contrast compared to CEST and MT. Conclusions: In this preliminary translational research, the kex MRI based on DS-removed omega plots has been demonstrated for in vivo imaging of clinical ischemic stroke patients. As a noninvasive and unique MRI contrast, kex MRI at 3 T may serve as a potential surrogate imaging biomarker for the metabolic changes of stroke and help for monitoring the evolution and the treatment of stroke.
KW - Chemical exchange saturation transfer (CEST)
KW - Omega plot
KW - Proton exchange rate (k)
KW - Stroke
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U2 - 10.1016/j.jneumeth.2020.108926
DO - 10.1016/j.jneumeth.2020.108926
M3 - Article
C2 - 32896540
AN - SCOPUS:85090580504
SN - 0165-0270
VL - 346
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
M1 - 108926
ER -