Chapter 11 Study Questions

Question 1

The International System of Units (SI) unit for measuring the absorbed dose in the patient is the:

Answer 1

gray-t (Gy-t)

Question 2

The SI measurement of radiation exposure in air is the:

Answer 2

gray-a (Gy-a)

Question 3

The SI unit used to report the equivalent dose, or occupational dose, to radiation workers in the United States is the.

Answer 3

Sievert (Sv)

Question 4

According to the law of Bergonie’-Tribondeau, which of the following types of cells would be most radiosensitive?

Answer 4

Embryonic tissue

Question 5

Short term effects of radiation are typically observed within.

Answer 5

3 months

Question 6

Which of the following is considered an observable short-term effect of radiation exposure?

Answer 6

Erythema

Question 7

The reduction of a limited operator’s exposure to ionizing radiation can be accomplished by.

Answer 7

Decreasing the time in the radiation field and increasing the distance from the radiation source

Question 8

The annual effective dose limit for a whole-body dose of occupational radiation for non-pregnant workers over the age of 18 is.

Answer 8

50 millisieverts (mSv)

Question 9

Which of the following are considered low dose techniques?

Answer 9

Increasing kVp, decreasing milliampere-seconds (mAs) and Using a minimum source-image receptor distance (SID) of 40 inches

Question 10

Which of the following changes will decrease the patient dose?

Answer 10

Using high-kVp techniques

Question 11

When radiation exposure occurs during pregnancy, the greatest risk of birth defects occurs when the dose to the uterus exceeds.

Answer 11

150 mGy-t

Question 12

Limited operators can reduce radiation risk to their patients by

Answer 12

minimizing repeat exposures and collimating closely to the part

Question 13

The radiation weighting factor for X-ray photons is.

Answer 13

1

Question 14

In equivalent dose of 0.400 SV would be converted to____mSv

Answer 14

0.400 x 1000= 400

Question 15

In our everyday work, the equivalent dose is used for.

Answer 15

radiation protection purposes

Question 16

The greatest cause of unnecessary radiation exposure to patients that can be controlled by the limited operator is.

Answer 16

repeat exposures

Question 17

Whenever the gonads are within________ of the margin of the radiation field, gonadal dose will be significantly reduced by shielding.

Answer 17

5 cm

Question 18

A pregnant radiation worker’s monthly equivalent dose limit is.

Answer 18

0.5 mSv

Question 19

A 33-year-old radiation worker would have a cook cumulative effective dose limit of.

Answer 19

33x10=330

Question 20

An erythema can develop on a patient if the radiation dose to the skin reaches.

Answer 20

2000 mSv

Question 21

When the dose to the patient is clarified by the type and energy of the radiation, it is termed the.

Answer 21

equivalent dose

Question 22

Patient dose in ready radiography is most often calculated according to the exposure level at the.

Answer 22

skin

Question 23

Short term effects of radiation will occur at doses greater than

Answer 23

500 mGy-t

Question 24

In diagnostic radiology, we are most concerned about which effect of radiation exposure?

Answer 24

Long-term effect

Question 25

The LD 50/30, or the lethal dose that would be fatal to 50% of the irradiated population within 30 days is.

Answer 25

3000 to 4000 mGy-t

Question 26

The greatest percentage of long term effects from radiation exposure will occur

Answer 26

at between 10-15 years

Question 27

Which of the following would be considered a long term effect of radiation exposure?

Answer 27

Cataracts, Life span shortening, Leukemia

Question 28

When a person becomes sick very fast due to a whole body dose of radiation in a short Period of time. This is referred to as.

Answer 28

acute radiation syndrome (ARS)

Question 29

The standard lead equivalency of the lead aprons used in the radiology department should be a minimum of 0.75.M lead.

Answer 29

False

Question 30

Radiographers should perform lead apron and glove inspection every six months.

Answer 30

True

Question 31

A human who receives an acute whole body exposure of 6.0 Sv will die.

Answer 31

True

Question 32

The earliest biologic effect that will be seen in the human body after exposure to radiation is nausea and vomiting.

Answer 32

False

Question 33

In diagnostic radiology, the absorbed dose and the equivalent dose are always the same value.

Answer 33

True

Question 34

Younger cells are no more sensitive to radiation than adult cells.

Answer 34

False

Question 35

Long term effects from radiation exposure are not predictable.

Answer 35

True

Question 36

The greatest risk to a fetus is during the last three months of pregnancy.

Answer 36

False

Question 37

Linear energy transfer (LET) is the amount of X-ray energy transfer on average per the length of passage through the tissue.

Answer 37

True

Question 38

When there is more oxygen in the tissues, it is more sensitive to radiation compared to tissues with low oxygen.

Answer 38

True