Steady-State Sequences for Metabolic Imaging with Hyperpolarized Carbon-13

描述（由申请人提供）：碳-13的超极化是一种新技术，可显著提高NMR光谱的灵敏度。超极化MR成像可以监测丙酮酸盐等底物的摄取和随后的代谢转化，从而为癌症和其他疾病的诊断和治疗监测提供新的方法。目前广泛使用的基于回波平面光谱成像（EPSI）或二维化学位移成像（2D CSI）的成像方法空间分辨率相对有限，限制了这些方法的应用并使图像解释复杂化。此外，血容量和血流量在确定局部信号强度方面起着重要作用，部分掩盖了代谢的影响。该提案描述了开发新的成像方法，利用超极化13 C光谱的稀疏性，以获得具有高空间和时间分辨率的化学位移选择性图像。这些方法是基于稳态自由进动（SSFP）成像序列，可以很容易地修改，以获得图像，调制的相对幅度和相位的信号从不同的代谢物，从而使每个代谢物的个别图像的重建。这些技术将使用体模和体内研究进行优化，然后与传统的2D CSI方法进行比较，以验证其性能。然后，该方法将被应用于肾细胞癌异种移植模型中的灌注和代谢的同时成像。这些研究的完成将为研究和开发新的癌症治疗方法提供有价值的新工具，包括抗血管生成药物和代谢干预。

DESCRIPTION (provided by applicant): Hyperpolarization of carbon-13 is a new technology that dramatically enhances the sensitivity of NMR spectroscopy. Hyperpolarized MR imaging can monitor both the uptake and the subsequent metabolic transformations of substrates such as pyruvate, enabling new approaches to diagnosis and treatment monitoring of cancer and other diseases. At present, widely used imaging methods based on echo planar spectroscopic imaging (EPSI) or two-dimension chemical shift imaging (2D CSI) offer relatively limited spatial resolution, which limits the applications of these methods and complicates image interpretation. In addition, blood volume and blood flow play an important role in determining local signal intensity, partially obscuring the effects of metabolism. This proposal describes the development of new imaging methods that exploit the sparsity of hyperpolarized 13C spectra to acquire chemical-shift selective images with high spatial and temporal resolution. These methods are based on steady-state free-precession (SSFP) imaging sequences, which can be readily modified to obtain images that modulate the relative magnitude and phase of signals from different metabolites, thereby enabling the reconstruction of individual images of each metabolite. These techniques will be optimized using phantom and in vivo studies and then compared with conventional 2D CSI methods to validate their performance. The methods will then be applied to simultaneous imaging of perfusion and metabolism in a xenograft model of renal cell carcinoma. Completion of these studies will provide valuable new tools for the study and development of novel treatments for cancer, including anti-angiogenesis drugs and metabolic interventions.