NDAEB Radiology Test Questions
with Answers
Structures that radiation can easily pass through are: - Answer-Radiolucent
3 structures that are radiolucent on an image - Answer-Metal restorations
enamel
dense areas of bone
The range of shades of grey to black to white is called: - Answer-Contrast
a 90 kVp setting requires less exposure time and produces an image that has: -
Answer-Low contrast
A 70 kVp setting requires longer exposure time and produces an image with: - Answer-
High contrast
What is density: - Answer-The overall blackness or darkness of a film.
An image with correct density allows the dentist to view: - Answer-Air spaces
Abscesses
White areas(tooth structure)
Gray areas (soft tissues)
The density is controlled by: - Answer-mAs
The mAs controls: - Answer-the amount of time given to exposure of the image
If exposure time is too short or a low milliampere (mA) setting is used, the resulting
image will: - Answer-will not have the correct overall density and appear light.
Factors that effect density of an image: - Answer-1. Distance from the xray tube to the
patient
2. Developing time and temp
3. Body size of the pt
Three geometric characteristics that affect the quality of an image: - Answer-Sharpness-
refers to detail, resolution, definition
Distortion- refers to the disproportionate change due to -/+ vertical angulation called,
Elongation and Foreshortening
Magnification-refers to the proportionate enlargement of a dental image
, Factors that affect contrast - Answer-kVp, Beam restriction, Grid, Processing, Filtration,
OID, Patient, Film
The sharpness of an image depends on: - Answer-Focal spot size
Film composition
Movement
Ionizing radiation - Answer-harmful and produces biologic changes in living tissues
Ionization causes: - Answer--disruption in cellular metabolism
- permanent damage to living cells and tissues
cells - tissues- organs- organ systems
What is the latent period? - Answer-The amount of time that elapses between exposure
to ionizing radiation and the appearance of observable clinical signs of tissue damage
When a large dose of radiation is absorbed in a short period, such as a nuclear accident
this is referred to as? - Answer-Acute radiation exposure
When small amounts of radiation is absorbed repeatedly over a long period of time and
the effects may not be abserved until years after the original exposure, this is referred to
as: - Answer-Chronic Radiation exposure
Who discovered xrays: - Answer-Wilhelm Conrad Roentgen
All xray machines have three primary components: - Answer-Tubehead
Extension arm
Control panel
The housing - Answer-metal body that contains the xray tube
Insulating oil - Answer-Fills the housing and surrounds the xray tube. Prevents
overheating by absorbing the heat
The tubehead seal - Answer-made of leaded glass or aluminum and it keeps the oil in
the tubehead and acts as a filter to the x-ray beam.
Xray beam - Answer-where xrays are produced
Transformer - Answer-device that alters the voltage of incoming electricity
PID - Answer-lead lined, used to aim xray beam at the film in patients mouth
Xray Tube - Answer-heart of the xray generating system
with Answers
Structures that radiation can easily pass through are: - Answer-Radiolucent
3 structures that are radiolucent on an image - Answer-Metal restorations
enamel
dense areas of bone
The range of shades of grey to black to white is called: - Answer-Contrast
a 90 kVp setting requires less exposure time and produces an image that has: -
Answer-Low contrast
A 70 kVp setting requires longer exposure time and produces an image with: - Answer-
High contrast
What is density: - Answer-The overall blackness or darkness of a film.
An image with correct density allows the dentist to view: - Answer-Air spaces
Abscesses
White areas(tooth structure)
Gray areas (soft tissues)
The density is controlled by: - Answer-mAs
The mAs controls: - Answer-the amount of time given to exposure of the image
If exposure time is too short or a low milliampere (mA) setting is used, the resulting
image will: - Answer-will not have the correct overall density and appear light.
Factors that effect density of an image: - Answer-1. Distance from the xray tube to the
patient
2. Developing time and temp
3. Body size of the pt
Three geometric characteristics that affect the quality of an image: - Answer-Sharpness-
refers to detail, resolution, definition
Distortion- refers to the disproportionate change due to -/+ vertical angulation called,
Elongation and Foreshortening
Magnification-refers to the proportionate enlargement of a dental image
, Factors that affect contrast - Answer-kVp, Beam restriction, Grid, Processing, Filtration,
OID, Patient, Film
The sharpness of an image depends on: - Answer-Focal spot size
Film composition
Movement
Ionizing radiation - Answer-harmful and produces biologic changes in living tissues
Ionization causes: - Answer--disruption in cellular metabolism
- permanent damage to living cells and tissues
cells - tissues- organs- organ systems
What is the latent period? - Answer-The amount of time that elapses between exposure
to ionizing radiation and the appearance of observable clinical signs of tissue damage
When a large dose of radiation is absorbed in a short period, such as a nuclear accident
this is referred to as? - Answer-Acute radiation exposure
When small amounts of radiation is absorbed repeatedly over a long period of time and
the effects may not be abserved until years after the original exposure, this is referred to
as: - Answer-Chronic Radiation exposure
Who discovered xrays: - Answer-Wilhelm Conrad Roentgen
All xray machines have three primary components: - Answer-Tubehead
Extension arm
Control panel
The housing - Answer-metal body that contains the xray tube
Insulating oil - Answer-Fills the housing and surrounds the xray tube. Prevents
overheating by absorbing the heat
The tubehead seal - Answer-made of leaded glass or aluminum and it keeps the oil in
the tubehead and acts as a filter to the x-ray beam.
Xray beam - Answer-where xrays are produced
Transformer - Answer-device that alters the voltage of incoming electricity
PID - Answer-lead lined, used to aim xray beam at the film in patients mouth
Xray Tube - Answer-heart of the xray generating system
