Concurrent High-Speed fMRI and Diffusion Tensor MRSI

总结/摘要 磁共振波谱成像（MRSI）、弥散张量成像（DTI）和功能磁共振成像（FMRI）的最新进展 功能磁共振成像（fMRI）有可能提高术前定位的临床实用性，以帮助诊断、治疗和预防。 计划和手术切除脑肿瘤。扩散张量光谱成像（DTSI）可以提供 关于细胞内性质的独特信息，例如粘度、细胞肿胀、亚细胞结构的限制， 和细胞质流动，这可能有助于表征浸润和炎症过程。dtsi 补充了最近开发的组织水的Q空间轨迹成像（QTI），其可以测量肿瘤 在线性编码中没有看到微观各向异性和各向同性异质性的特定异常 扩散张量成像（DTI）。静息态功能磁共振成像（rsfMRI）是一种很有前途的无任务全脑成像方法 补充基于任务的功能磁共振成像（tfMRI）和扩展功能皮层映射到受损患者。 评估这些先进的MRSI技术的个体和关节组织和功能特异性， 它们用于脑肿瘤患者的术前标测的临床效用是相当令人感兴趣的。然而，在这方面， DTSI与QTI和fMRI的整合受到DTSI的长扫描时间和运动敏感性的阻碍， 防止常规临床使用。 本提案的主要目的是开发一种方法，以降低DTSI的运动敏感性， 单次激发编码，将DTSI和高速fMRI集成到单个脉冲序列中，以减少长扫描 在多模态术前标测中， 脑瘤次要目的是评估DTSI的个体和关节敏感性和特异性， 用于组织表征的QTI。我们使用质子回波平面光谱成像的初步结果 （PEPSI）在3特斯拉的实验证明了（a）绘制代谢物扩散的年龄依赖性的可行性， 儿童和成人，（B）患有以下疾病的患者的高速fMRI和快速短TE 3D MRSI的术前标测 脑肿瘤，以及（c）在一次扫描中同时进行fMRI和MRSI的概念验证。这种做法的理由是， 研究表明，多模式术前标测提供了互补的生物标志物， 以及表征肿瘤组织状态和肿瘤边界与功能区皮质相关的特异性， 补充手术决策以及功能和肿瘤结果的预测。 如果成功，这项研究将促进先进的MRSI整合到临床脑映射协议中， 研究新的组织特异性生物标志物及其与病理学的关联。

Summary/Abstract Recent advances in MR spectroscopic imaging (MRSI), diffusion tensor imaging (DTI) and functional MRI (fMRI) have the potential to enhance the clinical utility of presurgical mapping to aid in the diagnosis, treatment planning and surgical resection of brain neoplasms. Diffusion tensor spectroscopic imaging (DTSI) can provide unique information on intracellular properties, such as viscosity, cell swelling, restriction in subcellular structures, and cytoplasmic streaming that may help to characterize infiltration and inflammatory processes. DTSI complements recently developed Q-space trajectory imaging (QTI) of tissue water, which can measure tumor specific abnormalities in microscopic anisotropy and isotropic heterogeneity not seen in linearly encoded diffusion tensor imaging (DTI). Resting state fMRI (rsfMRI) is a promising task-free whole brain approach complementing task-based fMRI (tfMRI) and extending mapping of eloquent cortex to patients with impairment. Evaluating the individual and joint tissue and functional specificity of these advanced MRSI technologies and their clinical utility for presurgical mapping in patients with brain tumors is of considerable interest. However, integration of DTSI with QTI and fMRI is been hampered by long scan times and motion sensitivity of DTSI, which prevents routine clinical use. The primary objective of this proposal is to develop a method to reduce motion sensitivity of DTSI using single-shot encoding, to integrate DTSI and high-speed fMRI into a single pulse sequence to reduce long scan times in multi-modal presurgical mapping, and to validate this approach in healthy adults and in patients with brain tumors. A secondary objective is to assess the individual and joint sensitivity and specificity of DTSI and QTI for tissue characterization. Our preliminary results using Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI) at 3 Tesla demonstrate (a) the feasibility of mapping the age dependence of metabolite diffusion in children and adults, (b) presurgical mapping with high-speed fMRI and fast short TE 3D MRSI in patients with brain tumors, and (c) proof-of-concept of simultaneous fMRI and MRSI in a single scan. The rationale of this research is that multi-modal presurgical mapping provides complementary biomarkers for improving sensitivity and specificity of characterizing tumor tissue status and tumor boundaries in relation to eloquent cortex, complementing surgical decision making and prediction of functional and oncological outcomes. If successful, this research will promote integration of advanced MRSI into clinical brain mapping protocols to study novel tissue-specific biomarkers and their association with pathology.