全开放式单边核磁共振技术研究及系统开发
收稿日期: 2014-03-16
修回日期: 2014-10-30
网络出版日期: 2014-12-05
基金资助
国家重大科学仪器设备开发专项资助项目(2013YQ170463).
Design and Construction of a Fully-Opened Unilateral Nuclear Magnetic Resonance System
Received date: 2014-03-16
Revised date: 2014-10-30
Online published: 2014-12-05
Supported by
国家重大科学仪器设备开发专项资助项目(2013YQ170463).
为了在单边磁体产生的逸散磁场中实现核磁共振技术，信号检测深度能满足相关应用需求，该文分析了非均匀磁场下的核磁共振技术条件，确定射频场目标，设计了单边平面射频线圈和探头，搭建出一套单边核磁共振实验系统．探头具有短脉宽(90°脉宽2.5 μs)，系统死时间短(10 μs)的特点，可实现15 μs 的半回波时间．应用该系统，在15.3 T/m 的巨大梯度磁场下，实现接近5 mm 厚度的信号检测，并利用单边磁体的自然梯度磁场，开展了恒定梯度磁场下的扩散测量方法探索．结果表明，该系统可满足需要一定探测深度的领域的应用需求．
关键词： 单边核磁共振系统; 平面线圈; SGSE-CPMG 序列; T2 弛豫时间; 扩散系数
汪红志1 , 2* , 刘翔1 , 苗志英1 , 陈珊珊2 , 施群雁1 , 徐罗元3 , 陆治勇3 , 刘利荣3 , 杨培强3 . 全开放式单边核磁共振技术研究及系统开发[J]. 波谱学杂志, 2014 , 31(4) : 488 -503 . DOI: 10.11938/cjmr20140404
The goal of the study is to design and construct a system that can be used to detect magnetic resonance signals generated in the stray magnetic field produced by fully-opened unilateral magnets. The radiofrequency (RF) probe was carefully designed to meet the detection depth requirement for specific applications, and tested on a unilateral nuclear magnetic resonance experiment system. The probe had a 90º pulse width as short as 2.5 s. The whole system has a short system dead time (i.e., 10 s), and the minimum half echo time was 15 s. The SGSE-CPMG experiment was performed on the system to acquire signals from a depth of 5 mm under a constant B0 gradient of 15.3 T/m. Diffusion coefficients were measured under the constant B0 gradient.
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