X-Ray Physics Review part 1

Question 1

What is the SI unit equivalent for REM (Radiation Equivalent Man)?

Answer 1

Seivert

Question 2

What units of measure account for differences in biologic tissue?

Answer 2

REM or Seivert

Question 3

What is the SI unit for Roentgen (R)?

Answer 3

c/Kg or coulombs per kilogram

Question 4

What unit is used to measure exposure in air?

Answer 4

the Roentgen (R) or coulombs per kilogram (c/Kg)

Question 5

What does LET stand for?

Answer 5

Linear Energy Transfer

Question 6

What does LET measure?

Answer 6

The amount of energy transferred to tissue per unit path length traveled in that tissue.

Question 7

What does RBE stand for?

Answer 7

Relative Biological Effectiveness

Question 8

As LET increases RBE _____

Answer 8

increases

Question 9

As RBE increases biological damage _____

Answer 9

increases

Question 10

What is the purpose of “Quality Factor (QF)” ratings of different types of radiation?

Answer 10

To be able to compare different types of radiations ability to produce biologic damage. Ie. alpha particles have a very high let and so have a high QF of 20. Xrays have a low LET and so have a low QF of 1.

Question 11

Where is Equivalent Dose used and in what units is it expressed?

Answer 11

It is used to report doses on radiation safety reports (in REM or Seiverts) and attempt to take in to account radiation damage from multiple sources

Question 12

What (biological thing) does Effective Dose Equivalent take into account?

Answer 12

The sensitivity of the different organs to determine the overall harm done

Question 13

How many rad to a Gray?

Answer 13

there are 100 rads in a Gray. rad/100 = Gray

Question 14

How many rem to a Seivert?

Answer 14

There are 100 rem in a Seivert. rem/100 = Seivert

Question 15

The unit of does equivalent is the ____

Answer 15

REM (Radiation Equivalent Man)

Question 16

What uses organ weighting factors to determine the risk of radiation induced cancer?

Answer 16

Effective dose equivalent

Question 17

What units are used to report occupational dose?

Answer 17

REM or Seiverts

Question 18

What does ALARA stand for?

Answer 18

As Low As Reasonably Acheivable

Question 19

No does is a ____ dose

Answer 19

safe

Question 20

What is the occupational worker effective does limit (annual)?

Answer 20

50 mSv or 5 rem

Question 21

What is the public exposure limit (annual)?

Answer 21

1 mSv or 0.1 rem

Question 22

Are stochastic effects guaranteed to happen?

Answer 22

No, there is only a probablility that they might occur. Also, not a direct relationship - ie. cancer or genetic effects

Question 23

What is the relationship between Non-stochastic effects and absorbed dose?

Answer 23

Non-stochastic effects (ie. erythema, cataracts, desquamation) increase in severity with absorbed dose.

Question 24

Is Direct effect or Indirect effect responsible for the production of free radicals?

Answer 24

Indirect Effect

Question 25

What is a molecular product produced via the radiolysis of water that is toxic to the cell?

Answer 25

Hydrogen peroxide

Question 26

Between Interphase and mitosis, which is the most radiosensitive?

Answer 26

Mitosis

Question 27

What are the cardinal rules of radiation protection

Answer 27

Time, Distance, Shielding

Question 28

How does collimation improve radiographic contrast?

Answer 28

by reducing scatter