Sophisticated Study of Time, Frequency and Statistical Analysis for Gradient-Switching-Induced Potentials during MRI

Karim Bouzrara; Odette Fokapu; Ahmed Fakhfakh; Faouzi Derbel

doi:10.3390/bioengineering10111282

Sophisticated Study of Time, Frequency and Statistical Analysis for Gradient-Switching-Induced Potentials during MRI

Bioengineering (Basel). 2023 Nov 3;10(11):1282. doi: 10.3390/bioengineering10111282.

Authors

Karim Bouzrara^{1

2}, Odette Fokapu^{3

4}, Ahmed Fakhfakh^{1

5}, Faouzi Derbel⁶

Affiliations

¹ Laboratory of Signals, Systems, Artificial Intelligence and Networks, Technopark of Sfax, Sakiet Ezzit, Sfax 3021, Tunisia.
² Department of Electrical Engineering, National Engineering School of Sousse, University of Sousse, Erriadh, Sousse 4023, Tunisia.
³ UMR CNRS 7338 Biomécanique and Bioingénierie, University of Technology of Compiègne, Dr. Schweitzer Street, 60200 Compiègne, France.
⁴ Laboratory of Innovative Technologies, University of Picardie Jules Verne, UR UPJV 3899, Aisne IUT Campus Cuffies-Soissons, 13 Avenue François Mitterrand, 02880 Compiègne, France.
⁵ National School of Electronics and Telecommunications of Sfax, Technopole of Sfax, Sfax 3018, Tunisia.
⁶ Smart Diagnostic and Online Monitoring, Leipzig University of Applied Sciences, Wachterstraße 13, 04107 Leipzig, Germany.

Abstract

Magnetic resonance imaging (MRI) is a standard procedure in medical imaging, on a par with echography and tomodensitometry. In contrast to radiological procedures, no harmful radiation is produced. The constant development of magnetic resonance imaging (MRI) techniques has enabled the production of higher resolution images. The switching of magnetic field gradients for MRI imaging generates induced voltages that strongly interfere with the electrophysiological signals (EPs) collected simultaneously. When the bandwidth of the collection amplifiers is higher than 150 Hz, these induced voltages are difficult to eliminate. Understanding the behavior of these artefacts contributes to the development of new digital processing tools for better quality EPs. In this paper, we present a study of induced voltages collected in vitro using a device (350 Hz bandwidth). The experiments were conducted on a 1.5T MRI machine with two MRI sequences (fast spin echo (FSE) and cine gradient echo (CINE)) and three slice orientations. The recorded induced voltages were then segmented into extract patterns called "artefact puffs". Two analysis series, "global" and "local", were then performed. The study found that the temporal and frequency characteristics were specific to the sequences and orientations of the slice and that, despite the pseudo-periodic character of the artefacts, the variabilities within the same recording were significant. These evolutions were confirmed by two stationarity tests: the Kwiatkowski-Phillips-Schmidt-Shin (KPSS) and the time-frequency approach. The induced potentials, all stationary at the global scale, are no longer stationary at the local scale, which is an important issue in the design of optimal filters adapted to reduce MRI artifacts contaminating a large bandwidth, which varies between 0 and 500 Hz.

Keywords: KPSS test; MRI; biomedical engineering; image and signal processing; induced potentials; medical image analysis and medical decision-making; stationarity test; surrogates; time and frequency analysis.

Grants and funding

The Open Access Publication Funds of HTWK Leipzig.