Dry-Type Phantom Emulating Quadrupole-Like Magnetic Field Distribution for Evaluation of Magnetoneurography

This study proposes a dry-type phantom for evaluating the accuracy of magnetoneurography (MNG). The phantom emulates the quadrupole-like pattern of the typical magnetic field distribution observed in MNG. It is composed of a printed circuit board (PCB) patterned with long rectangular coils, whose short and long edges measure 5 and 360 mm, respectively. The magnetic field distribution from the dry-type phantom was obtained using a 132-ch MNG system equipped with an array of vector-type superconducting quantum interference device (SQUID) flux sensors, and it showed a clear quadrupole-like pattern. The dry-type phantom is easier to handle and provides comparable or higher accuracy than that of the previously developed wet-type phantom in terms of goodness of fit (GOF).