Design, Characterisation and Performance of an Improved Portable and Sustainable Low-Field MRI System

Low-field permanent magnet-based MRI systems are finding increasing use in portable, sustainable and point-of-care applications. In order to maximize performance while minimizing cost many components of such a system should ideally be designed specifically for low frequency operation. In this paper we describe recent developments in constructing and characterising a low-field portable MRI system for in vivo imaging at 50 mT. These developments include the design of i) high-linearity gradient coils using a modified volume-based target field approach, ii) phased-array receive coils, and iii) a battery-operated three-axis gradient amplifier for improved portability and sustainability. In addition, we report performance characterisation of the RF amplifier, the gradient amplifier, eddy currents from the gradient coils, and describe a quality control protocol for the overall system.

Investigation of the spectral characteristics of low-frequency magnetic fields in different modes of operation of magnetic resonance imaging

The features of the amplitude-frequency and temporal parameters of magnetic fields created by MRI 3 T the gradient coils under various modes of its operation has studied. Low-frequency magnetic field induction changes has pulsed form - single pulses and various pulses shapes, different polarities and durations. Adequate controlled parameters for their hygienic evaluation are proposed