Learning objectives
How to:
- Recognize an MRI artifact in the Imaging.
- Classify them.
- Find strategies to minimize, avoid or take advantage of them.
Background
Despite recent Artificial Intelligence (AI) innovations that reduce acquisition time and improve image quality, there are many MRI artifacts that have to be detected and managed during acquisition.
Artifacts can be defined as any part of the image, which doesn't coincide with reality, generates noise, distorsion, or degrades image quality. They have a negative impact on the quality of interpretation and may have an impact on patient care.
They can be classified as a) Tissue, b) Movement, or c) Technical artifacts (table 1). They are...
Findings and procedure details
1. Tissue artifacts:
Magnetic susceptibility (also called metal artifact) (fig 2)
Definition: Magnetic field distortion due to a material with a particular susceptibility. It appears along air-tissue interfaces, near surgical implants or clips, or around metallic bodies or molecules such as deoxyhemoglobin, and in this case it can be used as a diagnostic tool. (fig 3)
Identification: Displacement, blurring and signal dropout artifacts at proximity of some material. The most sensible sequences are the Gradient Echo sequences (GE) and Diffusion Weighted Imaging (DWI). Also, sequences...
Conclusion
MR Artifacts alter image quality and can lead to interpretation mistakes or misdiagnoses. Many of them are automatically corrected on latest devices during acquisition preparation steps, or on the acquired signal thanks to AI algorithms. It remains important for radiologists and technicians to identify them, to investigate their cause(s), and formulate a strategy to minimize or avoid them.
Personal information and conflict of interest
P. A. Gutierrez:
Nothing to disclose
G. Dulcich:
Nothing to disclose
A. Soubielle:
Nothing to disclose
A. De Felippo:
Nothing to disclose
P. Puech:
Nothing to disclose
M. Pietrani:
Nothing to disclose
References
Krupa K, Bekiesińska-Figatowska M. Artifacts in magnetic resonance imaging. Pol J Radiol. 2015 Feb 23;80:93–106.
Bruce A Porter, M.D. William Hastrup, M.D. Michael L. Richardson, M.D. George E. Wesbey, M.D. Dana 0. Olson, M.D. Laurence D. Cromwell, Moss 1ajbert A. Classification and investigation of artifacts in magnetic resonance imaging. RadloGraphics [Internet]. 1987 Mar;7(2). Available from: https://www.researchgate.net/publication/19706974_Classification_and_investigation_of_artifacts_in_magnetic_resonance_imaging
McRobbie DW, Moore EA, Graves MJ, Prince MR. Improving Your Image: How to Avoid Artefacts. In: MRI from Picture to Proton. Cambridge University Press; 2017. p. 81–101.
Tomas Budrys...