Technical development of sodium magnetic resonance imaging of the human knee

在过去的25年里，硬件和软件的工程进步使得磁共振成像（MRI）在诊断和提高对许多人类疾病和失调的理解方面不可或缺。常规的临床MRI测量来自水的氢核（即质子，1H）的信号，它是组织中水性质的独特差异，产生图像对比度。然而，通过适当的工程设计，MRI可以从不同的细胞核获取信号，即体内天然丰富的钠（23Na）离子。钠与正常的细胞功能直接相关，并可能提供组织损伤的证据，尽管在常规MRI上表现正常。由于钠在组织中的浓度低，灵敏度低，物理反应复杂，因此钠核磁共振本身就非常具有挑战性。因此，钠磁共振成像是一种非标准成像技术，由于缺乏适当的电子设备和专门的成像脉冲序列，大多数临床1.5T（即磁场强度）MRI扫描仪无法使用。如果核磁共振成像扫描仪有很强的磁场，成像就会更灵敏。该方案将利用位于阿尔伯塔大学的一台非常强大的“三重强度”核磁共振扫描仪（4.7T）。

Engineering advances of hardware and software over the last 25 years have made magnetic resonance imaging (MRI) indispensable for the diagnosis and improved understanding of many human diseases and disorders. Routine clinical MRI measures signal from the hydrogen nucleus (i.e. proton, 1H) of water and it is unique differences in the water properties of tissue that yields image contrast. However, with the appropriate engineering, MRI can acquire signal from a different nucleus, namely the naturally abundant sodium (23Na) ion within the body. Sodium is linked directly to proper cell function, and may provide evidence of tissue injury despite normal appearance on conventional MRI. Sodium MRI is inherently very challenging because of low sensitivity due to sodium's low concentration in tissue and complicated physics responses. Therefore, sodium MRI is a non-standard imaging technique not available on most clinical 1.5T (i.e. strength of the magnetic field) MRI scanners because of the lack of appropriate electronics and specialized imaging pulse sequences. Imaging is more sensitive if the MRI scanner has a very strong magnetic field. This proposal will take advantage of a very strong "triple strength" MRI scanner (4.7T) located at the University of Alberta.