Sorce Dennis J, Michaeli Shalom
Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.
Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.
J Magn Reson. 2018 Aug;293:28-33. doi: 10.1016/j.jmr.2018.05.006. Epub 2018 May 24.
In the present study we derive expressions for relaxation rate functions due to dipolar interactions between identical spins in the rotating frames of rank greater than or equal to 3. The rotating frames are produced due to fictitious magnetic field as generated by amplitude and frequency modulated radiofrequency (RF) pulses operating in non-adiabatic regime. This solution provides a means for description of the relaxations during method entitled Relaxation Along a Fictitious Field (RAFF) in the rotating frame of rank n (RAFFn), in which a fictitious field is created in a coordinate frame undergoing multi-fold rotation about n axes (i.e., rank n). We validate the proposed model by comparison with the accepted trigonometric relations for relaxation rates between tilted frames. The agreement between the proposed model for RAFF3 and the trigonometric model is excellent.
在本研究中，我们推导了在秩大于或等于3的旋转坐标系中，相同自旋间偶极相互作用导致的弛豫速率函数表达式。这些旋转坐标系是由在非绝热 regime 中运行的幅度和频率调制射频（RF）脉冲产生的虚拟磁场产生的。该解决方案提供了一种方法，用于描述在秩为n的旋转坐标系中，沿虚拟场弛豫（RAFF）方法（RAFFn）期间的弛豫，其中在围绕n个轴进行多重旋转的坐标系（即秩为n）中创建了一个虚拟场。我们通过与倾斜坐标系之间弛豫速率的公认三角关系进行比较，验证了所提出的模型。RAFF3的所提出模型与三角模型之间的一致性非常好。
