MAGNETIC-RESONANCE-IMAGING OF PATIENTS WEARING A SURGICAL TRACTION HALO

Magnetic resonance images of patients wearing a surgical halo may have unacceptable artifacts if the halo has a conductive loop structure. T his study shows that the observed artifacts are predominantly due to e ddy currents generated in the halo by switching field gradients, and t hat these artifacts can be substantially reduced by adjusting the phas e encoding direction in MRI sequences so that it is parallel to the ax is of the halo.