LITHIUM-7 MR STUDIES OF RAT BRAIN AT 7 TESLA

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 锂在治疗双相情感障碍和反复发作的躁狂症方面是有效的。由于Li是一种CMS药物，其在大脑中的浓度可能与临床反应更密切相关。锂在大脑中的分布在锂治疗和定位其在大脑中的作用方面具有重要意义。因此，活体测量脑中锂浓度是必要的。磁共振(MR)是一种不涉及任何电离辐射或放射性同位素的方法，可以在体内非破坏性地观察Li。作为量化和绘制大脑锂的总体目标的一部分，我们将开发在特定吸收辐射(SAR)限制下的Li核的核Overhauser增强的光谱成像(SI)。进一步的开发将使用在正交模式下运行的较短的纯大脑线圈。该方法的优化将包括：a)体积定位和b)在SI数据收集之前的外部体积饱和。将使用最理想的方法测量大鼠大脑中的锂强度。然后，针对点扩展函数(PSF)引起的强度变化对SI数据进行校正。浓度是通过将强度与来自已知浓度的体模的等效体素的强度进行比较而获得的。最后，MR方法将与原子吸收(AA)法等“金标准”以及两种方法之间的一致性进行验证。新验证的方法将用于绘制大鼠大脑中锂通过大脑的不同阶段的锂分布。区域药代动力学将从与双相情感障碍相关的广泛解剖学领域进行研究。

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. Lithium (Li) is efficacious in the treatment of bipolar illness and recurrent episodes of mania. Since Li is a CMS drug, its concentration in the brain might be expected to relate more closely to clinical response. The distribution of lithium in the brain is of importance in Li therapy and in localizing its action in the brain. Thus, an in vivo measure of brain Li concentration is necessary. Magnetic resonance (MR), a method that does not involve any ionizing radiation or radioactive isotopes, can be used to observe Li non-destructively in an in vivo setup. As a part of the overall goal to quantify and map brain lithium, we will develop Spectroscopic Imaging (SI) with nuclear Overhauser enhancement of Li nucleus under the limits of Specific Absorbed Radiation (SAR). Further developments will be undertaken using shorter brain only coil operating in the quadrature mode. Optimization of the method will include: a) volume localization and b) outer volume saturation prior to SI data collection. Li intensities in the rat brain will be measured using the most optimal method. The SI data are then corrected for Point Spread Function (PSF) induced intensity changes. Concentrations are obtained upon comparing the intensities with those from equivalent voxels from a phantom of known concentration. Finally, the MR method will be validated against the "gold standard" such as atomic absorption (AA) method and the agreement between the two methods established. The newly validated methodology will be used to map out Li distribution in the rat brain at different stages of Li passage through the brain. Regional pharmacokinetics will be studied from broad anatomical areas of relevance to bipolar illness.