MR imaging of soft tissues adjacent to orthopaedic hardware: techniques to minimize susceptibility artefact

This article demonstrates and compares imaging of orthopaedic hardware (fixation plates, screws, Kischner wire and prostheses) using gradient-echo, spin-echo and fast spin-echo sequences. It describes simple techniques which minimize susceptibility artefact induced by these components at magnetic resonance (MR) imaging, allowing visualization of adjacent soft tissues. The article emphasizes the importance of selecting the appropriate imaging plane in order to avoid hardware distortion of slice select gradients, emphasizes the importance of selecting frequency encoding gradient axes in order to orientate the long axis of the artefact away from the tissue of interest and, finally, compares the marked susceptibility artefact observed adjacent to hardware using gradient-echo with the artefact reduction achieved by using fast spin-echo sequences.