Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA.
J Magn Reson. 2012 Jan;214(1):135-43. doi: 10.1016/j.jmr.2011.10.016. Epub 2011 Nov 15.
Multisite continuous wave (CW) electron paramagnetic resonance (EPR) oximetry using multiple quadrature field modulation harmonics is presented. First, a recently developed digital receiver is used to extract multiple harmonics of field modulated projection data. Second, a forward model is presented that relates the projection data to unknown parameters, including linewidth at each site. Third, a maximum likelihood estimator of unknown parameters is reported using an iterative algorithm capable of jointly processing multiple quadrature harmonics. The data modeling and processing are applicable for parametric lineshapes under nonsaturating conditions. Joint processing of multiple harmonics leads to 2-3-fold acceleration of EPR data acquisition. For demonstration in two spatial dimensions, both simulations and phantom studies on an L-band system are reported.
本文提出了一种使用多正交场调制谐波的多部位连续波（CW）电子顺磁共振（EPR）血氧计。首先，使用最近开发的数字接收器从场调制投影数据中提取多个谐波。其次，提出了一个正向模型，将投影数据与包括每个部位线宽在内的未知参数联系起来。第三，使用能够联合处理多个正交谐波的迭代算法报告了未知参数的最大似然估计。数据建模和处理适用于非饱和条件下的参数线形。多谐波的联合处理可将 EPR 数据采集速度提高 2-3 倍。在两个空间维度上进行演示，报告了在 L 波段系统上的模拟和体模研究。
