Portfolio

Question 1

Could you explain the role of a physicist in NM?

Answer 1

• QC programmes
• Dose audit
• Optomisation
• Also consider roles of MPE

Question 2

Describe the key components and function of a gamma camera

Answer 2

1. Collimator = Restricts angles on incidence localising incident photons
2. Scintilation crystal = Single crystal of NaI doped with thallium. Gamma photons hit and create light photons
3. Light pipe with silicon coupling grease which ensures good contact between crystal and PMTS. Also spreads light across sever PMTs
4. PMTs = Multiplies the signal through seccessive gain of electrons
5. Pulse height analyser = Height of Z signal proportional to energy of incoming photon
6. Pre-amplifier = converts current from anode to voltage pulse

Question 3

How would you handle a spill in nuclear medicne?

Answer 3

Assess:
- Volume of spill
- Activity
- Half-life
- Location

When cleaning spill, clean from outside in: Contain, don’t spread

Dispose of waste appropriately

Contamination monitoring is a legislative requirement and incidents must be reported and a datix report completed

Question 4

What is the role of DRLs in Nuclear Medicine?
Where do they come from?
Can the injected activity exceed the DRL?
How does this compare to DRLs in x-ray?

Answer 4

• DRLs provide guidance regarding appropriate or conventional levels of radiation dose to be delivered to patients. DRLs should be used to supplement, not replace, professional judgment and do not provide a dividing line between good and bad medicine but they offer a tool to educate imaging clinics on best practices.

-DRLs can be found in the ARSAC guidance

• Doses above the DRL are permitted but need to be justified, and approval given by ARSAC. Doses below the DRL must be approved by practitioner or MPE
• DRLs in x-ray are applied to populations, but NM DRLs are applied to every patient individually