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.

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。导言：超极化、代谢活性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。虽然理论上它不仅允许对底物进行体内成像，而且还允许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获取方案。超偏振13C代谢成像对速度和稀疏光谱的要求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：实现的序列利用稀疏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，其中只有频率在一定带宽内的成分被重建为“聚焦”，而其他成分则被严重模糊（“光谱断层合成”）。该序列在含有丙氨酸（Ala）、乳酸（Lac）和丙酮酸-丙酮酸水合物C1- c2酯（具有两个共振，PPE1和PPE2）的热平衡极化溶液的幻影上进行3 T测试，在C1羰基位置均富集到99% 13C。分别对具有单个空间交错（single-shot spCSI）和3个空间交错（3-shot spCSI）的螺旋CSI与相位编码CSI （FIDCSI）进行了比较。三次spccsi和单次spccsi的PPE1和PPE2的所有四个共振的代谢图显示出与FIDCSI图像相似的分辨率和定位特性。单次spccsi的Ala和Lac的代谢图由于混叠共振的信号重叠而包含轻微的伪影。资助来源：P41 RR009784，斯坦福大学高级磁共振技术中心，Gary H. Glover， 1995年1月1日- 2010年5月31日；R01 CA048269，磁共振肿瘤光谱成像；Daniel M. Spielman， 1990年7月23日- 2006年7月31日；R01 AA012388，酒精酒精体内扩散和光谱脑成像；Adolf Pefferbaum， 8/1/2000年6月30日。超偏振13C成像的应用[j]。的原因。医学，正在修订中。¿D. Mayer， Y.S. Levin， R.E. Hurd， G.H. Glover， D.M. Spielman¿稀疏光谱系统的快速代谢成像：超偏振13C成像的应用¿，程序ISMRM，第14届年会，西雅图，2006，提交。