Eliminating Metal Artifact Distortion Using 3D-PLACE

Michael Nicholas Hoff¹, Qing-San Xiang^1,2

A method is presented which removes in-plane and through-plane distortion stemming from MRI of a metallic hip prosthesis. Two images are acquired using 3D turbo spin-echo sequences differing only by added gradient lobes along the frequency encoding (FE) direction, which yield a relative phase ramp across the field-of-view. The undistorted FE coordinate for each voxel is encoded into the additional phase information contained in the phase difference image. Distortion correction of a Lego structure surrounding the prosthesis is demonstrated. The sequence modification is straightforward, the required scan time is minimal, and phase unwrapping is unnecessary for this technique.