RADIOLOGY EXAM 1 PRACTICE QUESTIONS (1-8) AND
ANSWERS
- -A 16 inch cylinder is used in the paralleling technique to:
a. reduce secondary radiation
b. avoid magnification of the image
c. avoid distortion of the image
d. avoid superimposition of anatomic structures
e. facilitate correct vertical angulation of the PID
- - -A dental x-ray machine operating at 75 kV is required to have a total aluminum filtration of
a. 2 mm
b. 2.5 mm
c. 2 inches
d. 2.5 inches
e. 2.75 inches
- - -A long FFD is desirable because
a. more radiation is absorbed by the tissues
b. the resulting radiation is more penetrating
c. more soft radiation strikes the object
d. the central rays of the primary beam are less divergent
e. overexposure rarely occurs
- - -A radiograph that has many dark and light areas but few gray areas is said to have
a. high density
b. low density
c. high contrast
d. low contrast
e. none of the above
- - -According to selection criteria
a. an asymptomatic edentulous patient does not require radiographs
b. a 14 year old patient will probably need posterior bitewings
c. a panoramic exam is needed for a new edentulous patient
d. very few patients need radiographs at 6 month intervals
e. all of the above
- - -All but which of the following are important to minimize patient exposure to radiation?
a. proper collimation
b. utilizing selection criteria to prescribe radiographs
c. proper filtration
d. darkroom quality assurance programs
e. not repairing tube head drift
- - -All of the following are examples of electromagnetic radiation except:
,a. x-rays
b. beta rays
c. gamma rays
d. microwaves
e. light waves
- - -All of the following reduce radiation exposure to the patient except
a. rectangular collimation
b. fast-speed film
c. overexposure with underdevelopment
d. lead aprons
e. aluminum filtration
- - -An angstrom unit is used to measure
a. radiation dose
b. radiation exposure
c. x-ray wavelength
d. half-value layer
e. amperage
- - -Any contaminated film that is processed
a. emerges from the processor sterilized
b. emerges from the processor disinfected
c. emerges from the processor decontaminated
d. emerges form the processor still contaminated
e. none of the above
- - -Arrange the following cells and tissues from most sensitive to least sensitive to ionizing radiation
a. nerve
b. bone
c. lymphocytes
d. gastrointestinal tract
1) b, a, d, c
2) c, a, d, b
3) c, b, a, d
4) c, d, a, b
5) c, d, b, a
- - -As stated in the previous question, after changing to a 16-inch PID, you decide to change from D- to
E-speed film. The new exposure at the same milliamperage and kilovolt peak for the lower premolar will
be:
a. 80 impulses
b. 24 impulses
c. 10 impulses
d. 1 second
e. 30 impulses
, - - -As the distance between the end of the PID and the receptor increases, the
a. intensity of the x-ray beam decreases
b. possibility of film fogging decreases
c. density of the film image increases
d. possibility of collimator cutoff decreases
e. sharpness of the film is affected
- - -At present the recommended MPD for non occupationally exposed individuals is
a. 500 mrem/year
b. 5 mrem/year
c. 5 rem/year
d. 5000 mrem/year
e. 0.5 mrem/year
- - -Autoclaving a contaminated exposed film packet
a. is not recommended because it takes too long
b. does not sterilize the packet
c. destroys the image
d. refines the image
e. none of the above
- - -Before prescribing dental radiographs, which of the following are needed?
a. history of previous radiographs
b. clinical examination
c. medical history
d. dental history
e. all of the above
- - -By having the operator stand 6 feet rather than 3 feet from a radiation source, the resultant
exposure is decreased by a factor of
a. 2
b. 4
c. 6
d. 8
e. 10
- - -Changing from 75 kV to 90 kV will
a. increase the radiolucency of the resultant radiograph
b. decrease radiographic density
c. decrease radiographic contrast
d. increase radiographic contrast
e. increase radiographic exposure time
- - -Daylight loaders are not recommended for infection control because of the
a. strength of the processing solutions
b. time delay
c. possibility of cross-contamination within the confined area of the loader
d. light leaks
ANSWERS
- -A 16 inch cylinder is used in the paralleling technique to:
a. reduce secondary radiation
b. avoid magnification of the image
c. avoid distortion of the image
d. avoid superimposition of anatomic structures
e. facilitate correct vertical angulation of the PID
- - -A dental x-ray machine operating at 75 kV is required to have a total aluminum filtration of
a. 2 mm
b. 2.5 mm
c. 2 inches
d. 2.5 inches
e. 2.75 inches
- - -A long FFD is desirable because
a. more radiation is absorbed by the tissues
b. the resulting radiation is more penetrating
c. more soft radiation strikes the object
d. the central rays of the primary beam are less divergent
e. overexposure rarely occurs
- - -A radiograph that has many dark and light areas but few gray areas is said to have
a. high density
b. low density
c. high contrast
d. low contrast
e. none of the above
- - -According to selection criteria
a. an asymptomatic edentulous patient does not require radiographs
b. a 14 year old patient will probably need posterior bitewings
c. a panoramic exam is needed for a new edentulous patient
d. very few patients need radiographs at 6 month intervals
e. all of the above
- - -All but which of the following are important to minimize patient exposure to radiation?
a. proper collimation
b. utilizing selection criteria to prescribe radiographs
c. proper filtration
d. darkroom quality assurance programs
e. not repairing tube head drift
- - -All of the following are examples of electromagnetic radiation except:
,a. x-rays
b. beta rays
c. gamma rays
d. microwaves
e. light waves
- - -All of the following reduce radiation exposure to the patient except
a. rectangular collimation
b. fast-speed film
c. overexposure with underdevelopment
d. lead aprons
e. aluminum filtration
- - -An angstrom unit is used to measure
a. radiation dose
b. radiation exposure
c. x-ray wavelength
d. half-value layer
e. amperage
- - -Any contaminated film that is processed
a. emerges from the processor sterilized
b. emerges from the processor disinfected
c. emerges from the processor decontaminated
d. emerges form the processor still contaminated
e. none of the above
- - -Arrange the following cells and tissues from most sensitive to least sensitive to ionizing radiation
a. nerve
b. bone
c. lymphocytes
d. gastrointestinal tract
1) b, a, d, c
2) c, a, d, b
3) c, b, a, d
4) c, d, a, b
5) c, d, b, a
- - -As stated in the previous question, after changing to a 16-inch PID, you decide to change from D- to
E-speed film. The new exposure at the same milliamperage and kilovolt peak for the lower premolar will
be:
a. 80 impulses
b. 24 impulses
c. 10 impulses
d. 1 second
e. 30 impulses
, - - -As the distance between the end of the PID and the receptor increases, the
a. intensity of the x-ray beam decreases
b. possibility of film fogging decreases
c. density of the film image increases
d. possibility of collimator cutoff decreases
e. sharpness of the film is affected
- - -At present the recommended MPD for non occupationally exposed individuals is
a. 500 mrem/year
b. 5 mrem/year
c. 5 rem/year
d. 5000 mrem/year
e. 0.5 mrem/year
- - -Autoclaving a contaminated exposed film packet
a. is not recommended because it takes too long
b. does not sterilize the packet
c. destroys the image
d. refines the image
e. none of the above
- - -Before prescribing dental radiographs, which of the following are needed?
a. history of previous radiographs
b. clinical examination
c. medical history
d. dental history
e. all of the above
- - -By having the operator stand 6 feet rather than 3 feet from a radiation source, the resultant
exposure is decreased by a factor of
a. 2
b. 4
c. 6
d. 8
e. 10
- - -Changing from 75 kV to 90 kV will
a. increase the radiolucency of the resultant radiograph
b. decrease radiographic density
c. decrease radiographic contrast
d. increase radiographic contrast
e. increase radiographic exposure time
- - -Daylight loaders are not recommended for infection control because of the
a. strength of the processing solutions
b. time delay
c. possibility of cross-contamination within the confined area of the loader
d. light leaks
