LRA-216 Review

Question 1

What describes the energy that is absorbed in matter from any type of ionizing radiation, and is considered the unit of absorbed dose?

Answer 1

rad/ gray

Question 2

What is the unit of dose equivalent or occupational exposure?

Answer 2

rem/ sievert

Question 3

What is the SI unit for Roentgen (R)?

Answer 3

coulomb/kilogram

Question 4

Which of the following is the SI unit for the rad?

Answer 4

gray

Question 5

What is the SI unit for the rem?

Answer 5

sievert

Question 6

_____ is a measure of the energy transferred to material as an ionizing particle travels through it. This measure is used to quantify the effects of ionizing radiation on biological specimens.

Answer 6

linear energy transfer (LET)

Question 7

A graphical representation of observed effects compared with radiation dose is termed a

Answer 7

dose response relationship (curve)

Question 8

How tall must primary protective barriers be?

Answer 8

7 ft

Question 9

A type of dosimeter consisting of radiation dosimetry film to determine the amount of exposure personnel have received is the

Answer 9

film badge

Question 10

A device containing lithium fluoride or calcium fluoride crystals to calculate the amount of personnel exposure is the

Answer 10

thermoluminescent dosimeter (TLD)

Question 11

A dosimeter containing filters composed of aluminum, tin, and copper, and thin strips of aluminum oxide, which when stimulated by a laser light becomes luminescent to the amount of radiation received is the

Answer 11

optically stimulated luminescent dosimeter (OSL)

Question 12

A device which uses an ionization chamber to determine personal exposure level is the

Answer 12

pen dosimeter

Question 13

The measurement of ionizing radiation doses to personnel is termed

Answer 13

dosimetry

Question 14

The primary protective barriers must consists of ___ inch lead

Answer 14

1/16

Question 15

Lead aprons worn during a mobile exam must have a lead equivalency of at least _____ mm.

Answer 15

0.5

Question 16

Modern radiation protection guidelines are established on the philosophy of keeping exposures

Answer 16

As low as reasonably achievable achievable (ALARA)

Question 17

The general public has an annual effective dose limit of _____ Seiverts.

Answer 17

0.05

Question 18

What is a measure of the radiation to a patient’s skin at the entrance surface?

Answer 18

Entrance skin exposure (ESE)

Question 19

Increasing the distance between the individual and the source of radiation is an effective method to reduce exposure to radiation. Distance utilizes what?

Answer 19

Inverse square law

Question 20

Controlled area design limits require barriers to reduce the exposure rate to less than _____ mrem/wk.

Answer 20

100

Question 21

Applying the inverse square law, if we double our distance from the source, the intensity at our new distance is _____ as much as the original intensity.

Answer 21

1/4

Question 22

Involuntary patient motion is best dealt with by

Answer 22

using a short exposure time and high mA

Question 23

Radiation monitoring of personnel is required when personnel receive _____% of the annual effective dose limit.

Answer 23

10

Question 24

Which of the following combinations would reduce patient radiation dose during an x-ray exam?

Answer 24

High kVp, Low mAs, increased filtration

Question 25

To within what percent of the SID must the collimator light and actual irradiated area be accurate?

Answer 25

2%

Question 26

How much total filtration is required when using over 70 kVp?

Answer 26

2.5 mm of Al EQ

Question 27

The number of repeat radiographs can be reduced by

Answer 27

eliminating voluntary patient motion using immobilization devices

Question 28

Half-value layer (HVL) is defined as the thickness of a designated absorber required to

Answer 28

decrease the intensity of the primary beam by 50% of its initial value

Question 29

An effective way of reducing patient dose is through

Answer 29

accurate and effective positioning

Question 30

Which of the following are placed between the patient and the image receptor (IR) to preferentially absorb scatter radiation?

Answer 30

Radiographic grids