1. WRAP AROUND OR ALIASING ARTEFACT Wrap or aliasing produces an image where anatomy that exists outside the FOV is folded on to the top of the anatomy inside the FOV.

2. CAUSE Aliasing is cause when anatomy that exists outside the FOV is mismapped inside the FOV. Anatomy outside the FOV still produces a signal if it is in close proximity to the receiver coil.

3. CAUSE Data from this signals must be encoded, i.e. allocated a pixel position. If the data are under sampled, the signal is mismapped into pixels within the FOV rather than outside. This can occur in both frequency encoding and phase encoding axis

5. Caused by under sampling the frequencies that are present in the echo regardless from where it originates.

7. Caused by under sampling along the phase axis

8. When a phase encoding is done it changes the phase from 0 to 3600 inside the FOV along the phase encoding direction

12. The above method increase the noise.

13. In order to avoid that a frequency filter is used to filter out frequencies that occur outside the selected FOV.

15. It increases the number of phase encoding performed (achieved by enlarging the FOV)