Dental Radiology Final Exam Study Guide
Questions And Answers Verified 100% Correct
Words always associated with mA - ANSWER -Number, quantity, amount,
density
Milliamperage - ANSWER -cathode controls thermionic emissions
Density - ANSWER -Darkness; amount of light transmitted through a film
What is kVp? - ANSWER -Kilovoltage potential; circuit that controls the speed of
electrons from cathode to anode
15% rule is always associated with what? - ANSWER -kVp
Half Value Layer - ANSWER -Measurement of the quality of the energy in the
primary beam
What is the purpose of kVp circuitry? - ANSWER -Controls speed of electrons
What is the filter? - ANSWER -2.5 mm thick; made of aluminum; filters long
waves from primary beam
What is a collimator? - ANSWER -Made of lead; has a hole; reduces the primary
beam to 2 3/4 in. on the face
What is rectification? - ANSWER -Blocking of the reversal of the alternation
current.
What is the Inverse Square Law? - ANSWER -The intensity of radiation/energy
varies inversely with the square of the distance
Contrast - ANSWER -Difference between densities
90 kVp= - ANSWER -Low contrast
60 kVp= - ANSWER -High contrast
, What principle is involved with increasing/decreasing the TFD? - ANSWER -
Inverse Square Law
Increased mA= - ANSWER -Increase in Density
Will penumbra be more visible in an exposure made with an 8" or a 16" cone? -
ANSWER -8"
What describes the proper direction of the CR in the Bis. angle technique? -
ANSWER -90 degrees to the imaginary bisector line
What describes the distance between the film and the tooth in the bis. angle
technique? - ANSWER -The film is placed as close to the tooth as possible
What is a variation of bisecting angle technique? - ANSWER -Occlusal
radiography
SLOB rule - ANSWER -Same on lingual, opposite on buccal
What is the best way to image the maxillary sinus? - ANSWER -Maxillary
left/right posterior topographic occlusal radiograph
What is the direct effect? - ANSWER -Primary beam hits and alters cells in body
tissue
Indirect effect - ANSWER -Damage to tissues not in the path of the primary beam
bc of ionization in molecules
Thompson scatter - ANSWER -An atom absorbs some of the photon's energy; the
photon continues with less energy; When the primary beam interacts with tissue in
this manner, scatter radiation is produced
What does Roentgen measure? - ANSWER -Amount in air
What does RAD measure? - ANSWER -About in everything except air and man
What does REM measure? - ANSWER -Radiation absorbed by man
Ionizing radiation is - ANSWER -Linear and non-threshold
Questions And Answers Verified 100% Correct
Words always associated with mA - ANSWER -Number, quantity, amount,
density
Milliamperage - ANSWER -cathode controls thermionic emissions
Density - ANSWER -Darkness; amount of light transmitted through a film
What is kVp? - ANSWER -Kilovoltage potential; circuit that controls the speed of
electrons from cathode to anode
15% rule is always associated with what? - ANSWER -kVp
Half Value Layer - ANSWER -Measurement of the quality of the energy in the
primary beam
What is the purpose of kVp circuitry? - ANSWER -Controls speed of electrons
What is the filter? - ANSWER -2.5 mm thick; made of aluminum; filters long
waves from primary beam
What is a collimator? - ANSWER -Made of lead; has a hole; reduces the primary
beam to 2 3/4 in. on the face
What is rectification? - ANSWER -Blocking of the reversal of the alternation
current.
What is the Inverse Square Law? - ANSWER -The intensity of radiation/energy
varies inversely with the square of the distance
Contrast - ANSWER -Difference between densities
90 kVp= - ANSWER -Low contrast
60 kVp= - ANSWER -High contrast
, What principle is involved with increasing/decreasing the TFD? - ANSWER -
Inverse Square Law
Increased mA= - ANSWER -Increase in Density
Will penumbra be more visible in an exposure made with an 8" or a 16" cone? -
ANSWER -8"
What describes the proper direction of the CR in the Bis. angle technique? -
ANSWER -90 degrees to the imaginary bisector line
What describes the distance between the film and the tooth in the bis. angle
technique? - ANSWER -The film is placed as close to the tooth as possible
What is a variation of bisecting angle technique? - ANSWER -Occlusal
radiography
SLOB rule - ANSWER -Same on lingual, opposite on buccal
What is the best way to image the maxillary sinus? - ANSWER -Maxillary
left/right posterior topographic occlusal radiograph
What is the direct effect? - ANSWER -Primary beam hits and alters cells in body
tissue
Indirect effect - ANSWER -Damage to tissues not in the path of the primary beam
bc of ionization in molecules
Thompson scatter - ANSWER -An atom absorbs some of the photon's energy; the
photon continues with less energy; When the primary beam interacts with tissue in
this manner, scatter radiation is produced
What does Roentgen measure? - ANSWER -Amount in air
What does RAD measure? - ANSWER -About in everything except air and man
What does REM measure? - ANSWER -Radiation absorbed by man
Ionizing radiation is - ANSWER -Linear and non-threshold
