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MR ARTIFACTS

An image artifact is a structure not normally present but vis- dible as a result of a limitation or malfunction in the hardware or software of the MRI device, or in other cases a consequence d of environmental influences as heat or humidity or it can be caused by the human body (blood flow, implants etc.)

Artifacts in magnetic resonance (MR) imaging result from e the complex interaction of contemporary imager subsystems, including the main magnet, gradient coils, radiofrequency (RF) e transmitter and receiver, and reconstruction algorithm used.



Sources of artifacts:
• Hardware Issues e.g. calibration, power stability

• Software problems e.g. programming errors
• Physiological phenomena e.g. blood flow .

Physics limitations e.g. Gibbs and susceptibility

Types of artifacts:

• Chemical Shift Artifact

Slice Phenomenon

Field inhomogeneity Aliasing

• Black Boundary Artifact

• Gibbs or Truncation Artifact

. Zipper Artifact

• Motion Artifacts (Phase direction)

. Entry

• Slice-overlap Artifact
•
• Magic Angle Effects

• Moire Fringes

• RF Overflow Artifact

• Central Point Artifact
•
Quadrature Ghost

Susceptibility Artifact

• Zero-fill (Zebra Artifact)

• Eddy Current Artifacts

• Diastolic Pseudogating
• Gadolinium Pseudolayering