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Contrast and Artefacts
•
IV contrast may be used during CT for head
and neck patients. This must be accounted for
when planning.
•
Create a volume which covers any contrast in
and around the treatment area.
•
Remove areas of bone, lung, airways from
this.
•
Give unit density of 1 to the contrast in this
region
•
If necessary, use a similar technique to
remove artefact caused by dental filling or
other high density regions, eg shunts