CT scanner Flashcards
1
Q
Why use wide bore ct scanners ?
A
Enable patients to be scanned in treatment position as there is a no. of scanners with increased gantry aperture diameter
2
Q
What is the SFOV?
A
The perimeter which determine how much anatomy is scanned
3
Q
how is an image produced?
A
linear attenuation coefficiente is measured at each detector by the Hounsfield uni
Each Hounsfield unit is assigned a voxel
each voxel forms a projection
4
Q
Why is 4d CT used?
A
Design more precise for moving tumours
can deliver treatment within a specific breathing cycle
- good for DIBH
5
Q
How many collimators are used?
A
2
-Reduces scattered radiation
6
Q
When is contact used and why?
A
Used for abdominal, pelvic and vascular disease as can highlight blood vessels
contrast blocks x-rays
