Development of transverse relaxation and susceptibility methods for high field MRI

高场 MRI 横向弛豫和磁化率方法的开发

• 批准号: 327723-2011
• 负责人: Wilman, Alan
• 金额: $ 2.7万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=572117
• 关键词: Development; transverse; relaxation; susceptibility; methods

Magnetic Resonance Imaging (MRI) systems using very strong magnetic fields that are greater than eighty thousand times the Earth's field are becoming increasingly available. These MRI systems are much stronger than standard clinical MRI systems that are at a field strength of 3.0 Tesla or lower. However, these higher field MRI systems still lack an adequate array of imaging methods for human imaging. New methods are needed to overcome the specific challenges of high field MRI. We will introduce new MRI methods for human brain imaging. Our work will provide insight into technical MRI and release new means to exploit inherent MRI contrast at both standard and high magnetic fields. Our methods are largely related to two features of high field MRI. First, the power used by higher fields increases with the square of the magnetic field, which can limit use of powerful MRI methods such as "T2 transverse relaxation" measurement. Second, high fields can provide a greater sensitivity to iron, a very important element in the human body. We will design methods that enable effective T2 measurement, and methods that increase the sensitivity to iron changes. The methods are designed by using computer simulations as well as experimental imaging of objects and human brain. The design process involves probing the means of performing MRI, which includes many more variables than x-ray imaging, and probing the response of tissue to these methods. The response is studied theoretically through Bloch equation and quantum mechanical simulations. Simulations are then verified with actual experiments on test tubes and on healthy human subjects. This work will lead to new MRI methods for human brain imaging.

磁共振成像（MRI）系统使用比地球磁场强8万倍以上的强磁场，这种系统正变得越来越实用。这些MRI系统比标准的临床MRI系统强得多，后者的场强为3.0特斯拉或更低。然而，这些高场核磁共振成像系统仍然缺乏足够的人体成像方法阵列。需要新的方法来克服高场MRI的具体挑战。我们将介绍新的MRI人脑成像方法。我们的工作将为技术MRI提供见解，并释放在标准和高磁场下利用固有MRI对比度的新手段。