Visualisation, tracking and navigation of instruments for MRI-guided interventional procedures

Interventional procedures using magnetic resonance (MR) image-guidance have recently increased in interest. A variety of methodologies for visualising and automatically tracking instruments, including endoscopes, RF ablation electrodes and catheters, have been developed and introduced to help the in terventionist to safely guide the device towards the target tissue. This ar ticle describes and compares characteristics of the four most commonly-used localisation and tracking systems for MRI-guided interventional procedures : those based on the susceptibility artifact of the device; those which int entionally created field inhomogeneity along the device; those relying on a n optical tracking system; and active tracking systems using micro-receive coils.