Brain H2D MRS: Implemation and Initial Applications

Brain H2D MRS：实施和初步应用

• 批准号: 6641178
• 负责人: ZHIYUE J WANG
• 金额: $ 17.87万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6641178
• 关键词: adult human (21+); bioimaging /biomedical imaging; brain disorders; brain imaging /visualization /scanning; brain metabolism; branched chain aminoacid; child (0-11); diet therapy; electron spin resonance spectroscopy; galactosemias; gamma aminobutyrate; human subject; ketoacid; magnetic resonance imaging; maple syrup urine disease; metabolism disorder; noninvasive diagnosis; patient oriented research; sugar alcohols; technology /technique development

DESCRIPTION (provided by applicant) The long-term objective is to apply 2D 1H magnetic resonance spectroscopy (MRS) techniques in studies of pediatric neurological disorders. 1H MRS is valuable for evaluating neurological brain diseases. However, there are limitations in current clinical 1H MRS examinations. Most peaks are crowded in a narrow aliphatic spectral window, and numerous low concentration metabolites are overshadowed by a few metabolites present in higher levels, and much valuable information is lost. Most metabolites have coupled spins, and 2D MRS separates the peaks in a second frequency dimension, greatly increasing the information content of the data. Application of 2D MRS in clinical examinations will enhance the abilities for diagnoses and patient management, and improve the understanding of disease processes. The specific aims are: (1) to implement 2D spin-echo double-quantum MRS pulse sequences for in vivo measurement of brain metabolites in 1.5T clinical scanners: (1a) to implement a localized pulse sequence optimized for GABA measurement; (1b) to implement localized pulse sequences for general detection of metabolites; (1c) to implement whole-brain measurement pulse sequences for general detection of metabolites. (2) to assign and evaluate peaks detected in the normal brain: (2a) to acquire spectra from metabolite solutions; (2b) to acquire brain spectra and baselines due to macromolecules in a group of adult normal volunteers; (2c) to assign the in vivo peaks and measure metabolite levels, and to determine optimal pulse sequences for studies of Aim 3; (2d) to acquire age-matched control spectra from normal children. (3) to explore the utility of the 2D MRS techniques in patients between the ages of 7 and 11 years: (3a) to study the effects of the ketogenic diet (KD) on brain GABA levels in seizure patients; (3b) to measure the brain?s level of branched chain amino-acids (BCAA) and keto-acids (BCKA) in maple syrup urine disease (MSUD); (3c) to test the hypothesis that low levels of brain galactitol are present even under a lactose restrictive diet; (3d) to study unassigned, unusual spectral peaks found in routine clinical MRS examinations. A localized 1D double-quantum filtered MRS pulse sequence will be modified into several 2D double quantum MRS pulses for localized and whole brain measurement. Different pulse parameters will be used for different types of spin systems. A frequency selective coherent transfer pulse will be used for optimal detection of GABA, and a broadband coherent transfer pulse will be used for all other 2D pulse sequences. The measurement procedures will be applied to normal subjects first. MRS measured GABA level before and after initiation of KD therapy will be compared in seizure patients and correlated with response. The MRS measurement of BCAAs and BCKAs will be conducted during metabolic crisis and in normal conditions in MSUD and correlated with clinical condition and serum BCAA and urine BCKA. In galactosemia, 2D MRS will be used to look for low levels of galactitol, and the MRS results will be correlated with the urine galactitol levels. 2D MRS will also be used to characterize unusual peaks found in clinical practice.

描述（由申请人提供） 长期目标是应用2D 1H磁共振波谱（MRS） 儿科神经系统疾病研究中的技术。 1H MRS 很有价值 用于评估神经性脑疾病。然而，也存在一些限制 当前临床1H MRS检查。大多数山峰都拥挤在狭窄的地方 脂肪族光谱窗口，和许多低浓度代谢物 被一些较高水平的代谢物所掩盖，并且非常有价值 信息丢失。大多数代谢物具有耦合自旋，并且 2D MRS 可以分离 第二频率维度的峰值，大大增加了信息 数据的内容。二维MRS在临床检查中的应用 增强诊断和患者管理能力，提高 了解疾病过程。具体目标是：（1）实现2D 用于脑活体测量的自旋回波双量子 MRS 脉冲序列 1.5T 临床扫描仪中的代谢物：(1a) 实现局部脉冲 针对 GABA 测量优化的序列； (1b) 实现局部脉冲 用于一般代谢物检测的序列； (1c) 实施全脑 用于一般代谢物检测的测量脉冲序列。 (2) 分配 并评估在正常大脑中检测到的峰值：(2a) 获取光谱 代谢溶液； (2b) 获取大脑光谱和基线 一组成年正常志愿者的大分子； (2c) 分配 in 体内峰值并测量代谢物水平，并确定最佳脉冲 用于目标 3 研究的序列； (2d) 获取年龄匹配的对照光谱 来自正常儿童。 (3)探索二维MRS技术在 年龄在 7 岁至 11 岁之间的患者：(3a) 研究 生酮饮食（KD）对癫痫患者大脑 GABA 水平的影响； (3b) 测量 大脑中支链氨基酸 (BCAA) 和酮酸 (BCKA) 的水平 枫糖浆尿病（MSUD）； (3c) 检验低水平的假设 即使在限制乳糖的饮食下，大脑中仍存在半乳糖醇； (3d) 至 研究常规临床 MRS 中发现的未分配的异常光谱峰 考试。局部一维双量子滤波 MRS 脉冲序列将是 修改为多个 2D 双量子 MRS 脉冲，用于局部和整体 大脑测量。不同类型将使用不同的脉冲参数 自旋系统。频率选择性相干传输脉冲将用于 GABA 的最佳检测，并将使用宽带相干传输脉冲 对于所有其他 2D 脉冲序列。测量程序将应用于 首先是正常科目。 MRS 测量开始之前和之后的 GABA 水平 KD 疗法将在癫痫患者中进行比较，并与反应相关。 BCAA 和 BCKA 的 MRS 测量将在代谢过程中进行 MSUD 中的危机和正常情况，并与临床状况相关 以及血清 BCAA 和尿液 BCKA。对于半乳糖血症，二维 MRS 将用于寻找 半乳糖醇含量低，MRS结果将与尿液相关 半乳糖醇水平。 2D MRS 还将用于表征发现的异常峰 在临床实践中。