ARTIFACTS

Question 1

Typically appear as multiple fine parallel lines immediately adjacent to high-contrast interfaces.

Answer 1

Gibbs artifacts (also known as truncation, ringing, or spectral leakage artifacts)

Question 2

Spatial displacement of water & fat due to their slightly different resonant frequencies.

Answer 2

Chemical shift artifact

Question 3

Seen as white & dark bands flanking an object along the freq. encoding direction.

Answer 3

Chemical shift artifact

Question 4

How can you reduce chemical shift artifacts?

Answer 4

• swap phase & freq. directions
• avoid narrow BW
• use fat suppression technique

Question 5

Artifacts due to differences in susceptibilities of tissues/materials.

Answer 5

Susceptibility artifacts

Question 6

Susceptibility artifacts are especially seen around….

Answer 6

Metal implants and at air-tissue or air-bone interfaces