Enabling Metabolic Imaging Using Feedback Driven Magnetic Resonance Spectroscopy

描述（由申请人提供）：已知糖酵解水平升高与各种癌症的存在和疾病分期相关。这种现象被称为Warburg效应，为氟脱氧葡萄糖正电子发射断层扫描（FDG PET）研究提供了生物学基础。FDG以类似葡萄糖的方式被细胞吸收，但随后在细胞中被困超过一小时。如果FDG分子中的19F原子被照射到18F，则可以使用断层扫描设备检测和定位它。放射性18FDG PET已被证明能够在临床可用的设备中对肿瘤进行空间定位，其长度可低至约8毫米，并已被广泛用于肿瘤的检测和分期超过30年。然而，它给病人带来了不小的放射性负担；因此，对人类进行的18FDG - FDG PET扫描通常限制在每位患者每12个月不超过一次，并且只能在组织诊断完成后进行。需要在回旋加速器中制造放射性FDG，以及提供放射性物质的安全处理/处置，这大大增加了其内在成本。在体内研究实验中，磁共振波谱成像（MRSI）技术也被用于检测和定位19FDG。这种方法不需要使FDG具有放射性；然而，由于磁共振成像研究中的信号要低得多，这种方法尚未转化为临床。MKT正在开发一种在核磁共振成像研究中提高单位时间内信噪比的方法。MKT技术利用众所周知的“超辐射”（SR）现象，也称为辐射阻尼，在MRSI脉冲序列后快速恢复磁平衡。这使得成像序列可以快速重复，因此随着时间的推移，平均信号可以增加。MKT方法是在标准的临床磁共振成像设备中使用反馈使能电路（FEC）和位于谐振线圈内的体积（包含一定数量的目标分子，称为补充自旋储层（SSR））产生SR条件，以创建感兴趣的分子（如FDG）的SR条件。通过提高信号平均率，我们提高了对目标分子的检测，并使使用核磁共振成像增强对氟化分子（如FDG）的检测成为可能。

DESCRIPTION (provided by applicant): Elevated levels of glycolysis are known to correlate with the presence and disease stage of various cancers. This phenomenon, known as the Warburg effect, provides the biological basis of Fluoro-Deoxyglucose Positron Emission Tomography (FDG PET) studies. FDG is taken up by the cell in a manner similar to glucose but then remains trapped in the cell for times exceeding an hour. If the 19F atom in the FDG molecule has been irradiated to 18F it can then detected and spatially located using the tomography device. Radioactive 18FDG PET has been shown to be able to spatially locate tumors on length scales down to approximately 8 mm in clinically available devices and has been widely used in the detection and staging of tumors for more than 30 years. However, it imposes a non-trivial radioactive burden on the patient; for this reason, 18FDG FDG PET scans for humans are typically limited to not more than once per 12 months per patient and only after a tissue diagnosis has already been made. The need to manufacture radioactive FDG in a cyclotron, as well as provide for safe handling/disposal of radioactive materials adds greatly to its intrinsic costs. Magnetic Resonance Spectroscopy Imaging (MRSI) techniques have been also used to detect and locate 19FDG in in vivo research experiments. This approach does not require the FDG be made radioactive; however, because of the much lower signal in an MRSI study this approach has not translated to the clinic. MKT is developing a method of improving the signal to noise per unit time in an MRSI study. The MKT technique leverages the well-known phenomenon of "super-radiance" (SR), also known as radiation damping, to rapidly restore magnetic equilibrium following an MRSI pulse sequence. This allows imaging sequences to be rapidly repeated so that the average signal over time can be increased. The MKT approach is to produce SR conditions in a standard clinical MR imaging device using a feedback enabled circuit (FEC) and a volume situated within the resonant coil containing a quantity of the target molecule, known as a Supplementary Spin Reservoir (SSR), to create SR conditions for a molecule of interest such as FDG. By increasing the signal averaging rate we improve detection of a target molecule and make it possible to use MRSI to enhance detection of fluorinated molecules such as FDG.