SODIUM MRI OF DIFFUSE AXONAL INJURY IN A MINIATURE PIG MODEL

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 细胞主动维持细胞内和细胞外钠浓度的梯度 隔间这种浓度梯度对宿主的正常细胞生长至关重要。 功能，其维护的高能量费用使其受到以下因素的敏感影响： 许多病理。 近年来研究发现，轴突损伤可导致钠离子通道 （NaCh）功能障碍和持续轴突Na+内流。 因为它能够敏感地 的空间分布，运动特征和局部环境的确定， 钠核在体内，我们提出，钠磁共振成像（MRI）是一个独特的 适用于非侵入性诊断和监测弥漫性轴索损伤的技术， 在病理学早期发生并在整个过程中持续存在的钠处理变化。 我们目前正在研究脑钠信号强度的变化， 小型猪弥漫性轴索损伤模型。 在旋转损伤之前和之后获取小型猪的质子和钠图像。 钠图像强度标准化为外部琼脂糖标准体模或稳态 已知钠浓度的内部隔室（例如玻璃体液、脑脊液） 然后与质子图像配准 感兴趣区域（ROI）分析用于比较 在损伤前和损伤后状态下的钠信号强度。 我们建议， 损伤前和损伤后状态之间的信号强度发生显著变化，特别是 在脑白色物质中，被认为是发生最实质性损伤的地方。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cells actively maintain a gradient in sodium concentrations between the intracellular and extracellular compartments. This concentration gradient is critically important to a host of normal cellular functions, and the high energetic expense of its maintenance causes it to be sensitively affected by many pathologies. It has recently been discovered that axonal trauma can lead to sodium channel (NaCh) dysfunction and persistent axonal Na+ influx. Because it is capable of a sensitive determination of the spatial distribution, motional characteristics, and local environment of the sodium nucleus in vivo, we propose that sodium magnetic resonance imaging (MRI) is a uniquely suitable technique for noninvasive diagnosis and monitoring of diffuse axonal injury due to the changes in sodium handling that occur early in the pathology and persist throughout its course. We are currently investigating changes in brain sodium signal intensity in a well-characterized miniature pig model of diffuse axonal injury. Proton and sodium images of the minature pig are acquired before and after rotational injury. Sodium images are intensity normalized to external agarose standard phantoms or to homeostatic internal compartments with known sodium concentrations (e.g. vitreous humor, cerebrospinal fluid) and then coregistered to the proton images. Region-of-interest (ROI) analysis is used to compare sodium signal intensities in the pre- and post-injury states. We propose that there will be significant changes in the signal intensity between the pre- and post-injury states, particularly in brain white matter where the most substantial injury is thought to occur.