Computational study of external fixation devices surface heating in MRI RF environment

Heating effect by external fixation devices under MRI RF field was studied numerically for both 1.5-T and 3-T MRI systems. It is found that changing insertion depth and pin spacing could largely affect the surface heating level. In 1.5-T MRI, smaller insertion depth and larger pin spacing will produce larger temperature rise. However, for 3T system, the relation is not very clear when insertion depth became larger than 5cm or when pin spacing became larger than 20cm. Effect of connection bar material on external fixator is also studied and the heating mechanism of the device is analysed.