EEG during MR imaging

Abstract

It is possible to record scalp EEG during the acquisition of gradient-echo/echo-planar MR images or MR spectra without significant degradation of the MR data. [1] Functional MR imaging or spectroscopy with simultaneous EEG recording allows the study of hemodynamic and metabolic changes in vivo in human subjects during cognitive tasks in normal subjects and in patients with paroxysmal epileptiform discharges or ictal events. [2] EEG registration in the MR scanner, however, is very susceptible to a variety of artifacts, particularly patient head movement and ballistocardiogram; the latter is related to head and body movements produced during systole. Despite having the head securely restrained, very small movements of the head produce high-amplitude, paroxysmal bursts on EEG that are impossible to differentiate from paroxysmal cortical epileptiform activity. This artifact results from currents produced by small movements of the EEG electrodes and wires …