Artifact (medical imaging)

Artifacts are misrepresentations of tissue structures seen in medical images produced by modalities such as Ultrasonography, X-ray Computed Tomography, and Magnetic Resonance Imaging. These artifacts are caused by a variety of mechanisms, such as: Physicians learn to recognize these artifacts to avoid confusing them with real pathology.
 * The underlying physics of the energy-tissue interaction (ie: Ultrasound-air)
 * Data acquisition errors (mostly from patient motion)
 * A reconstruction algorithm's inability to represent the anatomy.