Image artifacts are commonly encountered when performing MR imaging of the musculoskeletal system. Artifacts can be caused by a variety of factors, for example:

- by the patient themselves - involuntary motion, magnetic susceptibility-induced distortions of the magnetic field, the inherent electrical properties of tissue
- from equipment malfunction - faulty RF coils or scanner electronics, damaged magnet room Faraday cage, faulty MR Conditional electronic devices (pumps, anesthesia workstations, physiological monitoring equipment) located in the magnet room, magnet room environmental conditions (temperature, humidity)
- from poor operator technique – patient preparation and set-up within RF coil and/or scanner, imaging sequence choice and/or prescription, RF coil choice


While some artifacts are very obvious in an image, and the challenge then becomes one of ‘reading around’ the artifact, others can be more subtle and could be easily misinterpreted as a pathology. Understanding the source of an artifact can help during scanning to minimize its prevalence in the resulting image or possibly to remove it altogether. For artifacts already present in an image, this understanding can also help to differentiate artifact from genuine pathology, thereby minimizing the potential for a misdiagnosis. This interactive talk will present a range of common (and not-so-common) artifacts and solicit suggestions from the audience as to their source and possible mitigation strategies.


Learning Outcomes
1. Identify common image artifacts encountered in MSK MRI
2. Understand the source of each artifact
3. Understand strategies which can be used to remove or minimize the prevalence of the artifact

Acknowledgements

I would like to acknowledge my colleagues Drs Frick and Amrami, and physics assistants Renee, Jenna, Ian and Pam for contributing some interesting artifact images.