Patient Dosimetry

Question 1

the intensity of any x-ray beam, taken to represent “number of x-ray photons/mm2

Answer 1

K air

Question 2

Adding 3 mm aluminum to a typical radiographic x-ray beam (80kv) is likely to reduce Kair by __%

Answer 2

50%

Question 3

Radiation intensity incident on a patient

Answer 3

Entrance Kair

Question 4

Important determinants of entrance Kair

Answer 4

Patient thickness and composition

Question 5

The quantity that takes into account teh total amount of radiation incident on the patient

Answer 5

Kerma-Area product (KAP)

Question 6

measures the amount of radiation energy (E) absorbed/unit mass (M) of a medium

Answer 6

Absorbed dose

Question 7

best predicts the likelyhood of teh relevsant bioeffects (burns, epilation, cataracts)

Answer 7

Peak dose

Question 8

Used to predict lung stochastic (cancer) risk

Answer 8

Average organ dose

Question 9

Measures the total energy (J) imparted to a patient

Answer 9

Integral dose

Question 10

when radiation kills 90% of the cells, the surviving fraction is?

Answer 10

1/0th

Question 11

Concentration of energy deposition is technically characterized by the?

Answer 11

Linear enrgy transfer (LET)

Question 12

Example of high LET radiation

Answer 12

Alpha particles

Question 13

Examples of low LET radiation

Answer 13

Alpha particles

Question 14

rays having Wighting factor of 1`

Answer 14

x-ray, gamma rays and beta particles

Question 15

dosimetry metric that attempts to quantify biologic damage by different types of radiation

Answer 15

Equivalent dose

Question 16

Used to deal with the non-uniform dose distributions that occur in vitrually all radiologic examinations

Answer 16

Effective dose

Question 17

Very low effective dose is _mSv

Answer 17

0.1 msV

Question 18

effective dose between 1 and 10mSv

Answer 18

Moderate

Question 19

Cosmic radiation mSv

Answer 19

0.4 mSv/year