Chapter 36

Question 1

Leakage radiation must be less then ____mR/hr at a distance of 1 m from the protective housing

Answer 1

100

Question 2

The SID indicator must be accurate within __% of the indicated SID.

Answer 2

2

Question 3

The x-ray beam and the light must beam must coincide within ___% of the SID

Answer 3

2

Question 4

The PBL must be accurate to within ___ of the SID

Answer 4

2

Question 5

The variation in x-ray intensity should not exceed ___%

Answer 5

5

Question 6

The maximum acceptable variation in linearity is ___% from one mA station to an adjacent mA station.

Answer 6

10

Question 7

The SSD must not be less than ___cm on stationary fluroscopes and not less then ___ cm on mobile fluroscope.

Answer 7

38, 30

Question 8

___ time produces an audible signal when the fluroscopc time has exceeded 5 minutes

Answer 8

cumulative

Question 9

What device is used to cover the opening on the side of a fluroscopic table when the bucky tray is moved out the way?

Answer 9

bucky slot cover

Question 10

A ___ of at least 0.25mm Pb equivalent should be positioned between the fluroscopist and the patient

Answer 10

protective curtain

Question 11

____ radiation is the useful beam.

Answer 11

primary

Question 12

What are the two types of secondary radiation:

Answer 12

scatter and leakage

Question 13

The intensity of scatter radiation 1 m from the patient is approximately __% of the intensity of the useful beam at the patient.

Answer 13

0.1

Question 14

When PBL is activated, the collimators are automatically adjusted so that the radiation field matches the ____.

Answer 14

film size

Question 15

What are the two type of filtration?

Answer 15

inherent and added

Question 16

The glass envelope encasing the

x-ray tube, the insulating oil, and the glass window are examples of what type of filtration?

Answer 16

inherent

Question 17

Inherent materials amounts to approximately __mm of aluminum equivalent.

Answer 17

0.5

Question 18

A sheet of aluminum or its equivalent of appropriate thickness located outside the glass window of the tube housing above the collimator shutters are examples of what type of filtration?

Answer 18

added

Question 19

Added filtration is __ mm of aluminum equivalent

Answer 19

1

Question 20

The inherent and added filtration should combine to equal the required ___ of aluminum equivalent. (fixed tube, above 70kVp)

Answer 20

2.5

Question 21

The variation in the x-ray intensity should not exceed _%

Answer 21

5

Question 22

The maximum acceptable variation in linearity is __% from one mA station to an adjacent mA station

Answer 22

10

Question 23

The x-ray control panel must show _____.

a. beam on time
b. mAs used
c. positive beam limitation
d. automatic exposure controls

Answer 23

A

Question 24

What is the minimum requirement for filtration on x-ray equipment operating above 70 kVp?

a. 1.5 mm Al equivalent
b. 2.0 mm Al equivalent
c. 2.5 mm Al equivalent
d. 3.5 mm Al equivalent

Answer 24

c

Question 25

* The output intensities of reproduced exposures should not vary more than _____% from each other. a. 5 b. 10 c. 15 d. 20

Answer 25

A

Question 26

* Measuring the relationship between the output intensities of adjacent mA stations is a test of _____. a. HVL b. beam limitation c. reproducibility d. linearity

Answer 26

D

Question 27

* The source-to-skin distance must be no less than _____ cm on stationary fluoroscopes. a. 30 b. 38 c. 42 d. 48

Answer 27

B

Question 28

* The _____ is the primary protective barrier for the fluoroscopic x-ray tube. a. ceiling b. floor c. image intensifier d. table top

Answer 28

C

Question 29

A fluoroscopy system with automatic collimation must provide an unexposed border around the image at _____ above the table top. a. all heights b. 35 cm c. 25 cm d. 18 cm

Answer 29

A

Question 30

* The fluoroscopic exposure control switch is always a(n) _____ type. a. rheostat b. automatic c. deadman d. on-off

Answer 30

C

Question 31

* The bucky slot opening in the side of the table must be automatically covered with _____ mm Pb during fluoroscopy. a. 1.25 b. 1.0 c. 0.5 d. 0.25

Answer 31

D

Question 32

* A cumulative timer is designed to _____ of fluoroscopy beam-on time. a. make the radiologist aware b. turn off the radiation every 5 minutes c. prevent more than 10 minutes d. shut down the system after 15 minutes

Answer 32

A

Question 33

Primary radiation is _____. a. leakage radiation b. the scattered beam c. the useful beam d. all of the above

Answer 33

C

Question 34

The intensity of scatter radiation 1 meter from the patient is approximately _____ of the intensity of the incident beam at the patient. a. 0.01% b. 0.1% c. 10% d. 50%

Answer 34

b

Question 35

At the level of the tabletop, the intensity of the fluoroscopic beam should not exceed _____ for each mA of operation at 80 kVp. a. .02 mGy/hr b. 0.2 mGy/hr c. 21 mGy/min d. 0.21 mGy/min

Answer 35

C

Question 36

* A controlled area is one occupied primarily by _____. a. radiology personnel b. patients c. the general public d. both A and B

Answer 36

D

Question 37

* A secondary barrier is designed to absorb _____ radiation a. leakage b. scattered c. primary d. both A and B

Answer 37

D

Question 38

* A quantity that reflects both dose and volume of tissue irradiated is the _____. a. estimated skin exposure b. dose area product c. proportional region d. Rem

Answer 38

B

Question 39

* The design of an uncontrolled area in radiology is based on the NCRP recommended limit of _____ mGy/yr for the public. a. 50 b. 10 c. 1 d. 0.5

Answer 39

C

Question 40

* Devices designed to measure total accumulated radiation intensity are called _____. a. dosimeters b. integrators c. scintillation detectors d. photo cathodes

Answer 40

A

Question 41

* Gas-filled radiation detectors are based on the _____. a. thermoluminescence of crystals b. photoemission of electrons c. ionization of gas d. scintillation of phosphors

Answer 41

C

Question 42

* The _____ is used for precise calibration of the output intensity of diagnostic x-ray tubes. a. G-M counter b. ion chamber c. scintillation detector d. proportional counter

Answer 42

B

Question 43

* A Geiger-Muller counter is a(n) _____. a. scintillation detector b. optically stimulated dosimeter c. gas-filled detector d. thermoluminescent dosimeter

Answer 43

C

Question 44

``` Patient dose can be reduced by using___ I. faster screen II. higher kvp III. increased distance a. I b. II only c. II & III d. I, II, and III ```

Answer 44

a