Reduction of metal artefacts in musculoskeletal MR imaging.

The purpose of this article is to present a educational overview of practical tips to deal with metal artefacts in clinical musculoskeletal MRI. A brief theoretical explanation to understand the cause of metal artefacts is provided followed by a discussion on parameters to reduce these metal artefacts. Effects of adjustable parameters are demonstrated both in a volunteer with a titanium screw and a saline bag attached to the shoulder and in a in vitro experiment. These parameters include positioning of the patient with the long axis of metallic hardware parallel to B0, use of fast spin echo sequences, use of inversion recovery fat suppression, swapping phase and frequency encoding direction, use of view angle tilting, increasing the read-out bandwidth, and decreasing voxel size.