Distortion in magnetic resonance images obtained for stereotactic localization - Case report

The purpose of this paper was to note a potential source of error in magnet ic resonance(MR) imaging. Magnetic resonance images were acquired for stere otactic planning for GKS of a vestibular schwannoma in a female patient. Th e images were acquired using three-dimensional sequence, which has been sho wn to produce minimal distortion effects. The images were transferred to th e planning workstation, but the coronal images were rejected. By examination of the raw data and reconstruction of sagittal images throug h the localizer side plate, it was clearly seen that the image of the squar e localizer system was grossly distorted. The patient was returned to the MR imager for further studies and a metal c lasp on her brassiere was identified as the cause of the distortion.