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.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。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。所列机构为中心，不一定是研究者所在机构。介绍：超极化、代谢活性的MRI药物的发展既带来了前所未有的机遇，也带来了新的技术挑战。虽然它理论上允许在体内成像，不仅基板，而且下游代谢产物，纵向磁化的衰减需要快速采集方案。在超极化13 C代谢成像的应用中可能出现的对速度与稀疏光谱的组合的需要使得螺旋化学位移成像（spCSI）成为该应用的理想候选者。方法和讨论：所实现的序列利用稀疏频谱和共振频率的先验知识，通过对频谱域中的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，其中只有频率在特定带宽内的分量被重建为“焦点对准”，而其他分量则严重模糊（“光谱断层合成”）。在热平衡极化下，在含有丙氨酸（Ala）、乳酸盐（Lac）和丙酮酸-丙酮酸水合物C1-C2酯（具有两个共振，PPE 1和PPE 2）溶液的体模上，在3 T下测试序列，所有这些溶液在C1羰基位置富集至99%的13 C。将分别具有单个空间交错（单激发spCSI）和3个交错（3激发spCSI）的螺旋CSI与相位编码CSI（FIDCSI）进行比较。3次激发spCSI的所有四种共振以及单次激发spCSI的PPE 1和PPE 2的代谢图显示出与FIDCSI图像相似的分辨率和定位特性。单次激发spCSI的Ala和Lac的代谢图由于混叠共振的信号重叠而包含较小的伪影。 资金来源斯坦福大学先进MR技术中心加里H。格洛弗，01/01/1995-5/31/2010 <$R01 CA 048269，<$磁共振波谱肿瘤成像<$，丹尼尔M. Spielman，7/23/1990-7/31/2006 <$R01 AA 012388，<$酒精中毒的体内弥散和光谱脑成像<$，Adolf Psalbaum，8/1/2000-6/30/2010 相关出版物D. Mayer，Y.S. Levin，R.E.赫德，G.H.格洛弗，D. M. Spielman <$Fast Metabolic Imaging of Systems with Sparse Spectra：Application for Hyperpolarized 13 C Imaging <$，Magn. Reson.医学、在修订中。D. Mayer，Y.S. Levin，R.E.赫德，G.H.格洛弗，D. M.斯皮尔曼稀疏光谱系统的快速代谢成像：超极化13 C成像的应用，Proc ISMRM，第14届年会，西雅图，2006年，已提交。