Correction of systematic errors in frequency differential magnetic induction tomography

Abstract

Frequency differential magnetic induction tomography allows the reconstruction of images of relative conductivity spectra with the aid of magnetic AC fields and coil arrays. While the technique works well at high frequencies (> 1 MHz) the induced voltages due to physiological conductivities are very low in the β-dispersion range of most tissues. Even when using special cancellation techniques for the primary magnetic field (e. g. gradiometers) the signals are sensitive to severe systematic errors. Small phase errors in the receiver network, thermal drift and small movements of the gradiometers can produce huge spurious signals which make image reconstruction very difficult. In this paper we propose a new method which allows for the cancellation of such errors in case of frequency differential MIT. © Springer-Verlag 2007.