Lec 4 Dentomaxillofacial Radiology

Question 1

When needed, the basic principle of diagnostic imaging is that the ___________________ far outweighs the radiation-associated risks.

Answer 1

benefit to the patient

Question 2

To satisfy this principle, doses from dentomaxillofacial radiographic examination must be:
- Optimized to produce a ________, and
- Less than the threshold needed to cause any ____________, and
- Minimized to keep the risk of _________ within an acceptable range.

Answer 2

• diagnostically acceptable image
• deterministic effects
• stochastic effects

Question 3

There is no threshold or “safe dose”.

Answer 3

Linear No-Threshold Model

Question 4

TRUE OR FALSE

Complex damage to DNA, the basis of cancer formation, may occur with even one x-ray photon.

Answer 4

TRUE

Question 5

What does LNT mean?

Answer 5

Linear No-Threshold

Question 6

Low-dose radiation may have a protective effect.

Answer 6

Hormesis

Question 7

• The linear no-threshold model (LNT) posits that at doses _____________-, there is a linear relationship between dose and risk (orange dashed line) and that there is no threshold dose below which there is no additional risk.
• Alternate models propose that risk may be higher or lower than those predicted by the LNT model and that ________may have a protective effect with a threshold dose.

Answer 7

• less than 100 mSv
• low doses

Question 8

Evidence has shown that exposure to radiation of _____________ can contribute to cancer formation. This hypothesis considers that there is no threshold or “safe dose” below which there is no added cancer risk.

Answer 8

• more than 100 msv