Zhenxiong Wang1, Mehran Shaghaghi2, Shun Zhang3, Guiling Zhang3, Yiran Zhou3, Di Wu3, Zhuoli Zhang4, Wenzhen Zhu5, Kejia Cai6. 1. Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Departments of Radiology, Department of Bioengineering, the Center for MR Research, University of Illinois at Chicago, Chicago, USA. 2. Departments of Radiology, Department of Bioengineering, the Center for MR Research, University of Illinois at Chicago, Chicago, USA. 3. Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. 4. Department of Radiology, Northwestern University, Chicago, USA. 5. Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. Electronic address: zhuwenzhen8612@163.com. 6. Departments of Radiology, Department of Bioengineering, the Center for MR Research, University of Illinois at Chicago, Chicago, USA. Electronic address: kcai@uic.edu.
Abstract
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-1vs. 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.
BACKGROUND: To map and quantify the proton exchange rate (kex) of brain tissues using improved omega plots in ischemic strokepatients 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 strokepatients 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-1vs. 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 strokepatients. 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.
Authors: Michael T McMahon; Assaf A Gilad; Marco A DeLiso; Stacey M Cromer Berman; Jeff W M Bulte; Peter C M van Zijl Journal: Magn Reson Med Date: 2008-10 Impact factor: 4.668
Authors: Lian Li; Quan Jiang; Guangliang Ding; Li Zhang; Zheng Gang Zhang; Qingjiang Li; Swayamprava Panda; Alissa Kapke; Mei Lu; James R Ewing; Michael Chopp Journal: Stroke Date: 2009-01-15 Impact factor: 7.914
Authors: Lee Sze Foo; George Harston; Amit Mehndiratta; Wun-She Yap; Yan Chai Hum; Khin Wee Lai; Shahizon Azura Mohamed Mukari; Faizah Mohd Zaki; Yee Kai Tee Journal: Quant Imaging Med Surg Date: 2021-08