Reducing Chemical Shift Artefact
- Fat suppression techniques. E.g. STIR / SPIR (frequency selective fat suppression).
- Increase bandwidth (but SNR decreases). This reduces the size of the artefact. Increasing the magnitude of the read-out gradient is equivalent.
- Swap the frequency-encode and phase-encoding directions. This will not eliminate the chemical shift artefact but will rotate it to another anatomical area. This may also cause phase wraparound or flow-related artefacts to be shifted over the region of interest too.
- (Lower the external magnetic field strength....this is not a realistic option!)
Further reading on this topic:
Books: 1 p89, 2 p177-181, 3 p123-127
Online: Basics of MRI, MRItutor, St Paul's, Chickscope