On-treatment imaging equipment

Question 1

What are AMFPIs?

Answer 1

• Active matrix flat panel imagers

- indirect detection using amorphous silicon detectors

Question 2

How do AMFPIs work?

Answer 2

• Incoming x-rays exit from patient and interact with a metal plate to produce high energy electrons
• High energy electrons interact within the converting phosphor
• Optical photons interact within the converting phosphor scintillator to produce optical light photons
• Optical photons interact with photodiodesto produce photoelectrons which discharge the capacitors in each pixel
• Electrical signals from each pixel are read out in rows and fed to a computer to form an image

Question 3

How are image matching results calculated?

Answer 3

Registrations are calculated from distances between points, line segments etc
- Or by comparing grey scale intensities