在 7.0T 磁共振成像系统下利用化学交换饱和传递成像技术对压力诱导睡眠障碍大鼠模型中谷氨酸的脑图谱绘制。

Cerebral mapping of glutamate using chemical exchange saturation transfer imaging in a rat model of stress-induced sleep disturbance at 7.0T.

机构信息

Faculty of Health Sciences and Brain & Mind Centre, University of Sydney, Sydney, Australia.

Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.

出版信息

J Magn Reson Imaging. 2019 Dec;50(6):1866-1872. doi: 10.1002/jmri.26769. Epub 2019 Apr 29.

DOI:10.1002/jmri.26769

PMID:31033089

Abstract

BACKGROUND

Glutamate chemical exchange saturation transfer (GluCEST) imaging has been widely used in brain psychiatric disorders. Glutamate signal changes may help to evaluate the sleep-related disorders, and could be useful in diagnosis.

PURPOSE

To evaluate signal changes in the hippocampus and cortex of a rat model of stress-induced sleep disturbance using GluCEST.

STUDY TYPE

Prospective animal study.

ANIMAL MODEL

Fourteen male Sprague-Dawley rats.

FIELD STRENGTH/SEQUENCE: 7.0T small bore MRI / fat-suppressed, turbo-rapid acquisition with relaxation enhancement (RARE) for CEST, and spin-echo, point-resolved proton MR spectroscopy ( H MRS).

ASSESSMENT

Rats were divided into two groups: the stress-induced sleep-disturbance group (SSD, n = 7) and the control group (CTRL, n = 7), to evaluate and compare the cerebral glutamate signal changes. GluCEST data were quantified using a conventional magnetization transfer ratio asymmetry in the left- and right-side hippocampus and cortex. The correlation between GluCEST signal and glutamate concentrations, derived from H MRS, was evaluated.

STATISTICAL ANALYSIS

Wilcoxon rank-sum test between CEST signals and multiparametric MR signals, Wilcoxon signed-rank test between CEST signals on the left and right hemispheres, and a correlation test between CEST signals and glutamate concentrations derived from H MRS.

RESULTS

Measured GluCEST signals showed significant differences between the two groups (left hippocampus; 4.23 ± 0.27% / 5.27 ± 0.42% [SSD / CTRL, P = 0.002], right hippocampus; 4.50 ± 0.44% / 5.04 ± 0.34% [P = 0.035], left cortex; 2.81 ± 0.38% / 3.56 ± 0.41% [P = 0.004], and right cortex; 2.95 ± 0.47% / 3.82 ± 0.26% [P = 0.003]). GluCEST signals showed positive correlation with glutamate concentrations (R = 0.312; P = 0.038).

DATA CONCLUSION

GluCEST allowed the visualization of cerebral glutamate changes in rats subjected to sleep disturbance, and may yield valuable insights for interpreting alterations in cerebral biochemical information.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1866-1872.

摘要

背景

谷氨酸化学交换饱和传递（GluCEST）成像已广泛应用于脑部精神疾病。谷氨酸信号变化可能有助于评估与睡眠相关的疾病，并且在诊断中可能有用。

目的

使用 GluCEST 评估应激诱导睡眠障碍大鼠模型的海马体和皮质的信号变化。

研究类型

前瞻性动物研究。

动物模型

14 只雄性 Sprague-Dawley 大鼠。

磁场强度/序列：7.0T 小口径 MRI / 脂肪抑制，弛豫增强的涡轮快速采集（RARE）用于 CEST，自旋回波，点分辨质子磁共振波谱（ 1 H MRS）。

评估

将大鼠分为两组：应激诱导的睡眠障碍组（SSD，n = 7）和对照组（CTRL，n = 7），以评估和比较大脑谷氨酸信号变化。使用左、右侧海马体和皮质的常规磁化转移率不对称来量化 GluCEST 数据。评估 GluCEST 信号与来自 1 H MRS 的谷氨酸浓度之间的相关性。

统计学分析

CEST 信号与多参数 MR 信号之间的 Wilcoxon 秩和检验，左、右半球 CEST 信号之间的 Wilcoxon 符号秩检验，以及 CEST 信号与来自 1 H MRS 的谷氨酸浓度之间的相关检验。

结果

两组之间的测量 GluCEST 信号显示出显著差异（左侧海马体；4.23 ± 0.27% / 5.27 ± 0.42% [SSD / CTRL，P = 0.002]，右侧海马体；4.50 ± 0.44% / 5.04 ± 0.34% [P = 0.035]，左侧皮质；2.81 ± 0.38% / 3.56 ± 0.41% [P = 0.004]，右侧皮质；2.95 ± 0.47% / 3.82 ± 0.26% [P = 0.003]）。GluCEST 信号与谷氨酸浓度呈正相关（R = 0.312；P = 0.038）。