LITHIUM-7 MR STUDIES OF RAT BRAIN AT 7 TESLA

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来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 研究中心，而研究中心不一定是研究者所在的机构。 锂（Li）可有效治疗双相情感障碍和反复发作的躁狂。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。锂在脑中的分布在锂疗法中以及在脑中定位其作用中是重要的。因此，脑Li浓度的体内测量是必要的。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，可用于在体内装置中非破坏性地观察Li。作为量化和映射脑锂的总体目标的一部分，我们将在特定吸收辐射（SAR）的限制下开发具有Li核的核Overhauser增强的光谱成像（SI）。进一步的发展将采用更短的大脑只有线圈在正交模式下运行。该方法的优化将包括：a）体积定位和B）SI数据收集前的外部体积饱和。将使用最佳方法测量大鼠大脑中的Li强度。然后针对点扩散函数（PSF）引起的强度变化校正SI数据。在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后获得浓度。最后，将根据“金标准”（如原子吸收（AA）方法）验证MR方法，并确定两种方法之间的一致性。新验证的方法将被用来绘制出在不同阶段的锂通过大脑在大鼠大脑中的分布。将从与双相情感疾病相关的广泛解剖学区域研究局部药代动力学。

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.