Scott Bagwell, current PhD student, creating bespoke computational tool
MRI scanners have become increasingly popular for use in medical diagnosis. Their high resolution and non-intrusive imaging capability make them ideal for this purpose. They essentially consist of a set of main magnetic coils, which gives rise to a static magnetic field, contained within a cryostat.
A set of metallic radiation shields surround the cryostat. The scanners generate pulsed field gradients, utilised to produce images, through resistive coils contained within the imaging bore.
Despite active shielding the time varying gradient field generates Lorentz forces in the metallic components of the bore tube, which can cause deformations and vibrations in the mechanical parts of the scanner. These phenomena can cause unwanted effects such as image distortion and patient discomfort.
Through an EPSRC funded PhD case award, in partnership with Siemens Magnet Technology, a bespoke computational tool, based on hp-finite elements, is being developed to simulate these effects.
Pulsed magnetic field gradients generated by the resistive coils in an MRI scanner.
Electric field arising in the resistive coils of an MRI scanner and the surrounding air.
Interaction between the bore tube of the scanner and the time varying magnetic field through the generation of mechanical stresses.