The MR safety scan condition requiring for the external fixator to stay outside the scanner bore should be revised

Motivation: MRI scans for patients with external fixator, even made of non-ferromagnetic material, are often prohibited because the scan conditions given by the manufacturer would state the external fixator should stay outside the scanner bore. Goal(s): This study was performed to revisit this MRI safety scan condition and help some of the patients with ex-fix device in their clinical management. Approach: This study was performed with a phantom test at a 3T scanner. Results: The results suggest that the possible RF-induced heating is negligible if the ex-fix device stays outside a certain range from the isocenter but still inside the MRI scanner bore. Impact: The results of this study strongly suggests the patients with external fixator, who have often been prevented from getting MRI scans, could be allowed to get MRI scans, if the external fixator is at certain distance away from the isocenter.