Design of a fast field-cycling magnetic resonance imaging system, characterization and methods for relaxation dispersion measurements around 1.5 T

Abstract

L. Design of a fast fieldcycling magnetic resonance imaging system, characterization and methods for relaxation dispersion measurements around 1.5 T. The Review of scientific instruments 2020;91(2):024102.

An improved homogeneity design method for fast field‐cycling coils in molecular MRI

“…Thus far, dreMR has been demonstrated for quantification and localization of agents, 7,9,10 as well as measurement of tissue and agent T 1 ‐dispersion 11 ; however, it has not yet been used in a clinical trial. Previous designs for the FFC insert coil have typically consisted of a thick resistive solenoid with an outer shield to counter inductive coupling with the main magnet 6,10,12–14 . Interaction with the main magnet cannot be entirely negated, leading to small eddy currents within the bore which create artefacts during image acquisition.…”

“…Previous designs for the FFC insert coil have typically consisted of a thick resistive solenoid with an outer shield to counter inductive coupling with the main magnet. 6,10,[12][13][14] Interaction with the main magnet cannot be entirely negated, leading to small eddy currents within the bore which create artefacts during image acquisition. These eddy currents can be compensated for using a dynamic frequency adjustment or with the addition of a low power Helmholtz coil.…”

Joint multi‐field T1 quantification for fast field‐cycling MRI

“…Indeed, varying the main magnetic field within a defined range requires dedicated hardware and various approaches exist to realize FFC imaging systems 8 . In the clinical field range, FFC imaging is implemented by means of a insert coil together with the superconducting magnet provided by a commercial MRI system for 1.5T, 9‐11 or 3T 12 . This approach, also referred to as delta relaxation enhanced MR (dreMR), has auspicious applications for the detection and quantification of contrast agents with increased specificity and sensitivity 9,13‐15 .…”

Joint multi-field T$_1$ quantification for fast field-cycling MRI

“…Indeed, varying the main magnetic field within a defined range requires dedicated hardware and various approaches exist to realize FFC imaging systems [8]. In the clinical field range, FFC imaging is implemented by means of a B 0 insert coil together with the superconducting magnet provided by a commercial MRI system for 1.5 T [9,10,11] or 3 T [12]. This approach, also referred to as delta relaxation enhanced MR (dreMR), has auspicious applications for the detection and quantification of contrast agents with increased specificity and sensitivity [9,13,14,15].…”