Improving Aspects of In-Vivo Magnetic Resonance Spectroscopy Metabolite and Fat Quantification

磁共振波谱(MRS)是一种非侵入性(不需要外科手术)的方法，可以测量参与代谢(代谢物)的相关身体和大脑物质的水平。它使用核磁共振成像(MRI)单元。该研究计划的目的是在人体磁场强度为3T和较强磁场强度为9.4T的情况下，改进相关脑代谢物和体脂成分的MRS定量，这通常用于动物的临床前研究。这两个磁共振成像单位都在交叉癌症研究所(埃德蒙顿的癌症医院)。*MRS技术将为人类(3T)和动物研究(9.4T)开发能够改进不饱和脂肪(其结构中至少有一个双键的脂肪类型)和脂肪组织(如骨髓和腹部脂肪组织)中omega-3脂肪水平的测定。这些措施是相关的，因为脂肪不饱和度的水平已被证明会因骨质疏松、肥胖、肝病和癌症等疾病而发生变化。此外，乳腺组织中omega-3含量的可能变化可能与乳腺癌风险有关。体内脂肪组织中的omega-3脂肪酸水平很低(约12%)，因此，用MRS检测它是困难的，这是我们致力于克服的挑战。我们的长期目标包括应用开发的方法，在人类和动物(啮齿动物)的疾病模型中，将脂肪成分与癌症风险、肿瘤类型和治疗反应联系起来。*此外，将在9.4T设计和实施允许改进大脑新陈代谢测量的MRS技术。具体地说，将实现对谷氨酸、谷氨酰胺和GABA(相关大脑代谢物)的动态测量(代谢过程中发生的变化)的改进量化，以改进啮齿类动物的新陈代谢评估。我们的长期目标包括利用开发的方法来提高我们对脑肿瘤新陈代谢(在啮齿动物模型中)及其治疗反应的理解。另一个长期目标是调查MRS和PET(正电子发射断层扫描)测量结果之间的相关性，正电子发射断层扫描是一种使用放射性示踪剂的成像方法。从动物研究中获得的知识可以转化为在交叉癌症研究所新的PET/MRI装置上进行的人体研究。*所开发的技术还将有益于在加拿大正在进行的3T和9.4T的其他MRS研究，那里正在评估大脑新陈代谢或脂肪水平。这些方法将提供解决MRS遇到的代谢物和脂肪量化挑战的手段。

Magnetic Resonance Spectroscopy (MRS) is a non-invasive (does not require a surgical procedure) methodology that can measure levels of relevant body and brain substances involved in metabolism (metabolites). It uses an MRI (magnetic resonance imaging) unit. The objective of the research program is to improve MRS quantification of relevant brain metabolites and body fat composition at the human field strength of 3 T and the stronger magnetic field strength of 9.4 T, often used in pre-clinical research on animals. Both MRI units are at the Cross Cancer Institute (Edmonton's cancer hospital).*** MRS techniques that enable improved determination of unsaturated fat (type of fat with at least one double bond in its structure) and omega-3 fat levels in adipose tissue, such as bone marrow and abdominal fat tissue will be developed for human (3 T) and animal studies (9.4 T). The measures are relevant because levels of fat unsaturation have been shown to change due to diseases such as osteoporosis, obesity, liver disease and cancer. In addition, possible changes in omega-3 content of breast tissue may be associated with breast cancer risk. Levels of omega-3 fatty acids are low in body fat tissue (about 1 2 %) and therefore, its detection with MRS is difficult, a challenge we aim to overcome. Our long term goals involve applying the developed methods to correlate fat composition with cancer risk, tumour types and treatment response in humans and animal (rodent) models of disease. *** In addition, MRS techniques that allow for improved measures of brain metabolism will be designed and implemented at 9.4 T. Specifically, improved quantification of dynamic measures (changes that occur during metabolism) of glutamate, glutamine and GABA (relevant brain metabolites) will be achieved to improve metabolism assessment in rodents. Our long term goals involve utilizing the developed methodologies to improve our understanding of brain tumour metabolism (in rodent models) and its response to treatment. Another long term goal is to investigate correlations between measures obtained with MRS and PET (Positron Emission Tomography), an imaging methodology that uses radioactive tracers. Knowledge obtained from the animal studies can be translated to human studies on the new PET/MRI unit at the Cross Cancer Institute.*** The developed techniques will also be of benefit to other MRS studies being conducted at 3 T and at 9.4 T in Canada, where brain metabolism or fat levels are being assessed. The methods will provide the means to address metabolite and fat quantification challenges encountered with MRS.