13C, SPIRAL CHEMICAL SHIFT IMAGING, SPECTRAL UNDERSAMPLING, PYRUVATE, LACTATE

13C，螺旋化学位移成像，光谱欠采样，丙酮酸盐，乳酸盐

• 批准号: 7358767
• 负责人: DIRK MAYER
• 金额: $ 1.25万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7358767
• 关键词: 13C; SPIRAL; CHEMICAL; SHIFT; IMAGING

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. Introduction: The development of hyperpolarized, metabolically active MRI agents presents both unprecedented opportunities as well as new technical challenges. While it theoretically permits in vivo imaging of not only the substrate, but also downstream metabolic products, the decay of the longitudinal magnetization demands fast acquisition schemes. The need for speed in combination with the sparse spectra which can occur in the application of hyperpolarized 13C metabolic imaging makes spiral chemical shift imaging (spCSI) an ideal candidate for this application. Methods and Discussion: The implemented sequence exploits sparse spectra and prior knowledge of resonance frequencies to reduce the measurement time by undersampling the data in the spectral domain. As a consequence, multiple reconstructions of a given data set have to be computed in which only components with frequencies within a certain bandwidth are reconstructed ¿in-focus¿ while other are severely blurred (¿spectral tomosynthesis¿). The sequence was tested at 3 T on a phantom containing solutions of alanine (Ala), lactate (Lac), and pyruvate-pyruvate hydrate C1-C2 ester (with two resonances, PPE1 and PPE2) at thermal equilibrium polarization, all enriched to 99% 13C in the C1 carbonyl positions. Spiral CSI with a single spatial interleaf (single-shot spCSI) and 3 interleaves (3-shot spCSI), respectively, were compared to phase-encoded CSI (FIDCSI). Metabolic maps of all four resonances for 3-shot spCSI and of PPE1 and PPE2 for single-shot spCSI demonstrate similar resolution and localization properties as the FIDCSI images. Metabolic maps of Ala and Lac for single-shot spCSI contain minor artifacts due to signal overlap of aliased resonances. Funding Sources ¿ P41 RR009784, ¿Center for advanced MR Technology at Stanford¿, Gary H. Glover, 01/01/1995-5/31/2010 ¿ R01 CA048269, ¿Magnetic Resonance Spectroscopic Neoplasm Imaging¿, Daniel M. Spielman, 7/23/1990-7/31/2006 ¿ R01 AA012388, ¿In Vivo Diffusion and Spectroscopic Brain Imaging in Alcoholism¿, Adolf Pefferbaum, 8/1/2000-6/30/2010 Relevant publications ¿ D. Mayer, Y.S. Levin, R.E. Hurd, G.H. Glover, D.M. Spielman ¿Fast Metabolic Imaging of Systems with Sparse Spectra: Application for Hyperpolarized 13C Imaging¿, Magn. Reson. Med., in revision. ¿ D. Mayer, Y.S. Levin, R.E. Hurd, G.H. Glover, D.M. Spielman ¿Fast Metabolic Imaging of Systems with Sparse Spectra: Application for Hyperpolarized 13C Imaging¿, Proc ISMRM, 14th Annual Meeting, Seattle, 2006, submitted.

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。前言：超极化、代谢活性的MRI试剂的发展既带来了前所未有的机遇，也带来了新的技术挑战。虽然理论上它不仅可以对底物进行体内成像，还可以对下游代谢产物进行体内成像，但纵向磁化的衰减需要快速采集方案。在超极化13C代谢成像的应用中，对速度的要求与稀疏光谱的结合使得螺旋化学位移成像(SpCSI)成为这一应用的理想候选。方法和讨论：实现的序列利用稀疏的频谱和共振频率的先验知识，通过在谱域中对数据进行欠采样来减少测量时间。因此，必须计算给定数据集的多次重建，其中仅具有特定带宽内的频率的分量被聚焦重建，而其他分量被严重模糊(光谱层析合成)。该序列在3T的模体上进行测试，该模体包含丙氨酸(Ala)、乳酸(Lac)和丙酮酸-丙酮酸水合物C1-C2酯的溶液(具有两个共振，PPE1和PPE2)，所有这些溶液都在C1羰基位置富含99%的13C。将分别具有单个空间交错(单次激发spCSI)和3次交错(3次spCSI)的螺旋CSI与相位编码CSI(FIDCSI)进行了比较。3次SPCSI的所有四个共振以及单次SPCSI的PPE1和PPE2的代谢图显示出与FIDCSI图像相似的分辨率和局部化特性。由于混叠共振的信号重叠，单次激发spCSI的Ala和Lac的代谢图包含少量伪影。资金来源？P41 RR009784，斯坦福高级磁共振技术中心，Gary H.Glover，1/01/1995-5/31/2010？R01 CA048269？磁共振光谱肿瘤成像，Daniel M.Spielman，7/23/1990-7/31/2006？R01 AA012388？在酒精中毒中的体内扩散和光谱脑成像？，Adolf Pefferbaum，8/1/2000-6/30/2010相关出版物[D.Mayer，Y.S.Levin，R.E.Hurd，G.H.稀疏光谱体系的快速新陈代谢成像：超极化13C成像的应用。雷森。医学，在修订中。D.Mayer，Y.S.Levin，R.E.Hurd，G.H.Gever，D.M.Spielman？快速新陈代谢成像的稀疏光谱系统：超极化13C成像的应用，Proc ISMRM，第14届年会，西雅图，2006年，提交。