Computing Resolution for Neuromagnetic Imaging Systems

This paper proposes a novel signal-detection-theory-based definition for the resolution of Neuromagnetic imaging systems, and develops a Monte Carlo computer simulation method to compute the resolution. Using the resolution as a performance measure, the performance of various types of sensor hardware is assessed. The assessments include performance improvements due to the increase in the number of sensors and performance changes due to the change in the gradiometer baseline or change in the helmet size. We compare the performance difference between planar and axial gradiometer arrays, and also compare the performance between the conventional radial sensor array and a vector sensor array. We compute the resolution of two existing Neuromagnetic sensor arrays, MEGvisionTM (Yokogawa Electric Corporation, Tokyo, Japan) and Elekta-Neuromag TRIUXTM (Elekta Corporate, Stockholm, Sweden).