Fundamentals of Diagnostic Imaging
October 16, 1996
Test A
7. Which of the following has a negative charge?
a. Neutron
b. Proton
c. Electron
d. X-ray
e. Gamma ray
8. Radioactive half-life is:
a. exactly one half of the quantity of material now present
b. the time necessary for one half of the mass to disappear
c. the time necessary for one atom to disintegrate
d. the time required for the radioactivity to reach one half of its original value
9. The difference between x-rays and gamma rays is:
a. gamma rays always have higher energy than x-rays
b. their origin
c. x-rays produce bremsstrahlung radiation and gamma rays do not
d. gamma rays travel faster
10. X-ray photons
a. have no rest mass and are neutral
b. have no rest mass and a charge of +2
c. have a negative charge and no rest mass
d. have 1 atomic mass unit (amu) and are neutral
11. Electromagnetic radiation ____________ than particulate radiation
a. is generally heavier
b. has a higher electrostatic charge
c. is generally more penetrating
d. is more densely ionizing
12. What are the two principle classes of ionizing radiation?
a. MRI and ultrasound
b. MRI and electromagnetic
c. Particulate and electromagnetic
d. Particulate and ultrasound
13. Photons of the electromagnetic spectrum have wavelengths:
a. inversely proportional to photon velocity
b. directly proportional to photon frequency
c. usually designated in the wave equation by the letter “c”
d. inversely proportional to photon frequency
21. When compared with visible light, x-rays have greater
a. mass
b. velocity
c. wavelength
d. frequency
22. Tissue that absorbs x-radiation is called:
a. radiolucent
b. radiotransmission
c. radiopaque
d. radioemission
23. If the exposure rate I meter from a radioactive source is 9 mR/hr, what will be the exposure rate 3
meters from the source?
a. 9 mR/hr
b. 3 mR/hr
c. 1 mR/hr
d. 0.9 mR/hr
24. The inverse square law states that
a. intensity is inversely proportional to the square of the distance
b. the square of the intensity is inversely proportional to the distance
c. intensity is directly proportional to the square of the distance
d. the square of the intensity is directly proportional to the distance
25. The inverse square law relationship between intensity and distance from a source is a result of
a. attenuation
b. scatter
c. absorption
d. divergence
26. To apply the inverse square law one must know:
a. one distance and one intensity
b. two distances and one intensity
c. the frequency or the wavelength of radiation
d. energy, distance, and intensity
27. If the distance from a point source is tripled, the intensity will be
a. one third
b. three times
c. nine times
d. one ninth
34. The primary purpose of the glass envelope is to:
a. control leakage radiation
b. cool the tube
c. filter low energy characteristic radiation
d. provide a vacuum
e. ensure against electric shock
35. The small filament is chosen during radiography when the heat load is
a. high and visibility of detail is less important
b. high and visibility of detail is more important
c. low and visibility of detail is less important
d. low and visibility of detail is more important
36. The heel effect occurs because of
a. reduced tube current
b. the space charge effect
c. difference between the incident and the refractive angles
d. photon absorption
e. the shape of the filament
37. The main reason for using the line focus principle is to
a. increase the heat capacity of the anode
b. decrease exposure times
c. decrease the heel effect
d. decrease the effective focal spot size
38. You decide to perform a skull series of x-rays on a 40 year old male patient with cranial injuries post
MVA (motor vehicle accident) to rule out skull fracture. The lateral skull measurement is 14 cm. The
normal TCF at 40” is –4. What would be the most likely technique?
a. 86 kvp, 3 mAs
b. 60 kvp, 11 mAs
c. 86 kvp, 11 mAs
d. 100 kvp, 3 mAs
Test B
Choose the single best answer unless otherwise directed
1. The difference in taking a radiograph with or without a grid is:
a. the grid exposure requires more kVp
b. the grid exposure requires more mAs
c. the non grid exposure requires more kVp
d. the non grid exposure requires more mAs
2.
The reason lateral or flexion/extension cervical spine x-rays do not normally require the use of a grid is
that
a. the neck is typically smaller in its lateral dimension
b. the neck is actually larger in its lateral dimension
c. there is an air gap between the neck and the film
d. is the way Dr. Ryan teaches it in positioning class
3.
You can always identify the aspect of the x-ray tube that is anode end of the tube because
a. it always points north
b. it is always the round end of the tube
c. there is one main power-supplying electrical cable
d. there are two main power-supplying electrical cables
e. it always points south
4.
The approximate speed of anode rotation during x-ray production is ____ rpm
a. 300
b. 3,000
c. 30,000
d. 300,000
5.
The approximate heat storage capacity of a typical anode found in a small office setting is ____ HU
a. 15
b. 150
c. 1,500
d. 15,000
e. 150,000
6.
The problem with a 10 degree target angle (anode angle) in a typical chiropractic practice is
a. the accompanying focal spots are too small
b. the head capacity of the anode is too great
c. the cost is prohibitive
d. anode heel cutoff will be excessive
7.
Which of the following is not part of acceptance testing of newly installed x-ray equipment?
a. have the grids x-rayed and view the resulting film
b. check to be sure that the grids have actually been installed
c. check the legend on the grid to confirm the grid ratio is as ordered
d. ask to see the results of a star pattern or other test of focal spot size
e. check the oil level in the x-ray tube
8-12 MATCHING Match the appropriate piece of x-ray equipment with its function
8. Timer
a. Guarantees that the operator remains behind the 2nd barrier during exposure
9. Flasher/Printer
b. Provides most of the medicolegal information for each film
10. Grid
c. Converts 110 volts or 220 volts input to kilovolt levels of output
11. Deadman Switch
d. Stops the tube current after a preselected time interval
12. Transformer
e. Absorbs x-rays scattered by the patient before striking the film
13. Which one of the following is not a property of x-ray photons?
a. They process no mass
b. They have no electrical charge
c. They are capable of ionizing biologic matter
d. They travel at approximately ½ the speed of light after bremsstrahlung interactions
14. The formula kVp x mAs is used to calculate:
a. the heating of the anode during single phase generated x-ray exposures
b. the heating of the anode during three phase generated x-ray exposures
c. the heating of the anode during high frequency generated x-ray exposures
d. all of the above
e. none of the above
15. T/F Given the same series of x-rays with kV adjustment to maintain film contrast performing the series
on a high frequency generating system will result in less heat generated in the anode when compared to
a single phase system.
16. You wish to make a single x-ray exposure using technique settings of 90 kVp, 300 mA and 1 second.
You discover this exceeds tube limits. How could you safely make the exposure to obtain an isodense
film?
a. use a higher mA setting (400) with all other factors equal
b. use a lower mA setting with all other factors equal
c. use a lower mA (200), adjust the time (1.5 sec), and leave the kVp alone
d. any of the above
e. none of the above
17. During x-ray production infrared heat is produced in the anode when
a. outer shell electrons of the target material are temporarily elevated from their orbits then fall back
into their original orbit
b. outer shell electrons of the target material are ionized
c. inner electrons of the target material are temporarily elevated from their orbits then fall back into
their original orbit
d. inner shell electrons of the target material are ionized
18. The kV ripple associated with single phase x-ray generating systems is ____%
a. 1
b. 6
c. 100
d. 120
19. Which one of the following statements is true about high frequency x-ray generators?
a. They produce 120 bursts of x-rays per second
b. They regulate incoming line voltage during the exposure
c. They produce more anode heat per exposure compared to single phase
d. The 60 Hz power supply is half wave rectified
20. What is the effect on HVL as a diagnostic x-ray beam passes through matter?
a. The HVL increases
b. The HVL decreases
c. The HVL stays the same
21. What is meant by the term TVL?
a. It is the thickness of lead that will reduce x-ray intensity by one tenth
b. It is the thickness of any given material that will decrease the intensity of a given x-ray beam by
10%
c. It is the thickness of any given material that will decrease the intensity of a given x-ray beam by
90%
d. It is one tenth of the thickness of any given material necessary to stop all x-rays of a particular xray beam
22. The unsharpness of the edge of an object seen on a radiograph is due to
a. the anode heel effect
b. the inverse square law
c. HVL or TVL
d. Parallax
23. The sensitivity speck found in x-ray film emulsions is usually made of:
a. silver halide
b. silver bromide
c. bromine
d. silver
e. silver sulfite
24. The resolution of a dedicated extremity film/screen combination is in the range of __ line pairs per mm
a. 1
b. 5
c. 10
d. 20
e. 50
25. Film latitude is a measure of
a. a film’s ability to record density and contrast between 0.25 OD and 2.5 OD
b. a film’s ability to be processed between 88 F and 95 F
c. a film’s ability to be optimally developed in variable chemical concentrations
d. a film’s ability to be exposed in front of any type of intensifying screen
26. T/F A characteristic curve is produced on two radiographic films, A and B. Comparing the straight line
portion of each curve it is noted that the slope of B is greater than A. It could be said that B
demonstrates more contrast than A.
27. As demonstrated on a characteristic curve, as film contrast decreases, film latitude
a. increases
b. decreases
c. stays the same
28. Reciprocity failure is of most concern imaging small body parts using the highest mA setting on high
frequency generators and
a. extremity imaging systems (100 speed)
b. 400 speed film/screen systems
c. 600 speed film/screen systems
d. 800 speed film/screen systems
e. 1200 speed film/screen systems
29. The prime agent found in automatic processing chemicals used for developing the black on
radiographs is
a. phenidone
b. metol
c. sodium carbonate
d. glutaraldehyde
30. The fixing chemical usually contains
a. metol
b. phenidone
c. methadone
d. thiosulfate
31. Assuming a starting optimal kVp technique the 15% rule states
a. if you decrease the kVp by 15% you balance this by increasing the mAs by 15%
b. if you decrease the kVp by 15% you balance this by decreasing the mAs by 15%
c. if you decrease the kVp by 15% you balance this by increasing the mAs by 50%
d. if you decrease the kVp by 15% you balance this by increasing the mAs by 100%
Answers
* these answers have not been verified and my not be correct
Part A 7.C 8.D 9.B 10.A 11.C 12.C 13.D 21.D 22.C 23.C 24.A 25.D 26.B 27.D 34.D 35.D
36.D 37.D 38.A
Part B 1.B 2.C 3.D 4.B 5.E 6.D 7.E 8.D 9.B 10.E 11.A 12.C 13.D 14.A 15.A 16.C 17.A 18.C
19.B 20.A 21.C 22.D 23.E 24.C 25.A 26.B 27.B 28.E 29.A 30.D 31.D