Kim Sanga, Choi Bup Kyung, Park Ji Ae, Kim Hyung Joong, Oh Tong In, Kang Won Sub, Kim Jong Woo, Park Hae Jeong
Department of Pharmacology, School of Medicine, Kyung Hee University, Seoul 02447, Korea.
Department of Biomedical Engineering, School of Medicine, Kyung Hee University, Seoul 02447, Korea.
Diagnostics (Basel). 2021 Mar 22;11(3):569. doi: 10.3390/diagnostics11030569.
Previous imaging studies have shown the morphological malformation and the alterations of ionic mobility, water contents, electrical properties, or metabolites in seizure brains. Magnetic resonance electrical properties tomography (MREPT) is a recently developed technique for the measurement of electrical tissue properties with a high frequency that provides cellular information regardless of the cell membrane. In this study, we examined the possibility of MREPT as an applicable technique to detect seizure-induced functional changes in the brain of rats. Ultra-high field (9.4 T) magnetic resonance imaging (MRI) was performed, 2 h, 2 days, and 1 week after the injection of N-methyl-D-aspartate (NMDA; 75 mg/kg). The conductivity images were reconstructed from B1 phase images using a magnetic resonance conductivity imaging (MRCI) toolbox. The high-frequency conductivity was significantly decreased in the hippocampus among various brain regions of NMDA-treated rats. Nissl staining showed shrunken cell bodies and condensed cytoplasm potently at 2 h after NMDA treatment, and neuronal cell loss at all time points in the hippocampus. These results suggest that the reduced electrical conductivity may be associated with seizure-induced neuronal loss in the hippocampus. Magnetic resonance (MR)-based electrical conductivity imaging may be an applicable technique to non-invasively identify brain damage after a seizure.
先前的影像学研究已经表明癫痫发作的大脑中存在形态畸形以及离子迁移率、含水量、电学特性或代谢物的改变。磁共振电阻抗断层成像（MREPT）是一种最近开发的用于测量高频组织电学特性的技术，它能提供与细胞膜无关的细胞信息。在本研究中，我们检验了MREPT作为一种可应用技术来检测大鼠大脑中癫痫发作诱导的功能变化的可能性。在注射N-甲基-D-天冬氨酸（NMDA；75mg/kg）后2小时、2天和1周进行超高场（9.4T）磁共振成像（MRI）。使用磁共振电导率成像（MRCI）工具箱从B1相位图像重建电导率图像。在NMDA处理大鼠的各个脑区中，海马体的高频电导率显著降低。尼氏染色显示在NMDA处理后2小时海马体中细胞体明显萎缩且细胞质浓缩，并且在所有时间点海马体中都存在神经元细胞丢失。这些结果表明电导率降低可能与癫痫发作诱导的海马体神经元丢失有关。基于磁共振（MR）的电导率成像可能是一种用于无创识别癫痫发作后脑损伤的可应用技术。
