Fluoroscopy Exam Questions with 100% Correct
Answers
What is the maximum mA used when operating fluoroscopy?
The maximum mA used during fluoroscopy is 5mA or less.
Despite lower mA, the patient dose is higher during fluoroscopy than it is in radiographic exams
because the x-ray beam exposes the patient for a considerably longer period of time.
What structure of the eye is responsible for scotopic vision?
Rods cell (almost entirely responsible for night vision) more sensitive than cone cells.
Personnel wearing protective lead aprons during a procedure where the minimum
exposure rate is 5mR/hr must contain the equivalent of what
thickness in lead?
.25mm lead equivalent (according to NCRP)
Total Brightness Gain is determined by which 2 factors?
It is determined by minification gain & flux gain.
Total brightness gain is a measurement of the increase in image intensity achieved by an image
intensification tube.
Cones are used primarily for daylight vision. This type of vision is referred to as?
Photopic vision
,What is the minimum filtration required for fluoroscopy machines?
2.5mm Aluminum or Aluminum equivalent
In DF, spatial resolution is determined by what 2 components?
In DF, spatial resolution is determined both by image matrix and by the size of the image
intensifier.
Spatial resolution is limited by pixel size.
What is the formula used to determine brightness gain?
Minification Gain X Flux Gain
What is the Input Phosphor is made up of?
Cesium Iodide (CsI)
What does the Image Intensifier of a fluoroscopic machine do?
The Image Intensifier raises the intensity of available light into the cone-vision region, where
visual acuity is the greatest.
What is NOT a non-stochastic effect?
They do not cause genetic effects (cancer)
Non-stochastic effects are biologic somatic effects that exhibit a threshold dose below which the
effect does not occur.
Stochastic Effects are?
,Stochastic effects are effects that occur by chance and which may occur without a threshold level
of dose.
The probability is proportional to the dose and the severity is independent of
the dose.
In the context of radiation protection, the main stochastic effect is cancer.
Radiographs and image intensified fluoroscopic images are best visualized under what
illumination levels?
under illumination levels of 10 to 1000ml (milliamberts)
Which part of the eye behaves like a diaphragm of a photographic camera to control the
amount of light emitted to the eye?
The Iris
The iris is located between the cornea & the
lens of the eye.
During low light conditions, the iris dilates & allows for more light to enter.
What is vignetting?
Vignetting is the loss of brightness at the edge of the image.
, The following factors influence dose rate at a table top fluoroscopic machine:
mA
kVp
Collimation
Filtration
Exposure time
Target panel distance
Fovea Centralis is?
Fovea Centralis are cones concentrated at the center of the retina.
What is the magnification for an image viewed with a 9" image intensifier tube that has
used a 5" diameter area during magnification?
Magnification= input screen / diameter of input screen used during magnification.
9/5
magnification = 1.8
The Fluoroscopic Automatic Brightness Control (ABC) should be evaluated for quality
control when?
Anually
To ensure the component is properly working.
Answers
What is the maximum mA used when operating fluoroscopy?
The maximum mA used during fluoroscopy is 5mA or less.
Despite lower mA, the patient dose is higher during fluoroscopy than it is in radiographic exams
because the x-ray beam exposes the patient for a considerably longer period of time.
What structure of the eye is responsible for scotopic vision?
Rods cell (almost entirely responsible for night vision) more sensitive than cone cells.
Personnel wearing protective lead aprons during a procedure where the minimum
exposure rate is 5mR/hr must contain the equivalent of what
thickness in lead?
.25mm lead equivalent (according to NCRP)
Total Brightness Gain is determined by which 2 factors?
It is determined by minification gain & flux gain.
Total brightness gain is a measurement of the increase in image intensity achieved by an image
intensification tube.
Cones are used primarily for daylight vision. This type of vision is referred to as?
Photopic vision
,What is the minimum filtration required for fluoroscopy machines?
2.5mm Aluminum or Aluminum equivalent
In DF, spatial resolution is determined by what 2 components?
In DF, spatial resolution is determined both by image matrix and by the size of the image
intensifier.
Spatial resolution is limited by pixel size.
What is the formula used to determine brightness gain?
Minification Gain X Flux Gain
What is the Input Phosphor is made up of?
Cesium Iodide (CsI)
What does the Image Intensifier of a fluoroscopic machine do?
The Image Intensifier raises the intensity of available light into the cone-vision region, where
visual acuity is the greatest.
What is NOT a non-stochastic effect?
They do not cause genetic effects (cancer)
Non-stochastic effects are biologic somatic effects that exhibit a threshold dose below which the
effect does not occur.
Stochastic Effects are?
,Stochastic effects are effects that occur by chance and which may occur without a threshold level
of dose.
The probability is proportional to the dose and the severity is independent of
the dose.
In the context of radiation protection, the main stochastic effect is cancer.
Radiographs and image intensified fluoroscopic images are best visualized under what
illumination levels?
under illumination levels of 10 to 1000ml (milliamberts)
Which part of the eye behaves like a diaphragm of a photographic camera to control the
amount of light emitted to the eye?
The Iris
The iris is located between the cornea & the
lens of the eye.
During low light conditions, the iris dilates & allows for more light to enter.
What is vignetting?
Vignetting is the loss of brightness at the edge of the image.
, The following factors influence dose rate at a table top fluoroscopic machine:
mA
kVp
Collimation
Filtration
Exposure time
Target panel distance
Fovea Centralis is?
Fovea Centralis are cones concentrated at the center of the retina.
What is the magnification for an image viewed with a 9" image intensifier tube that has
used a 5" diameter area during magnification?
Magnification= input screen / diameter of input screen used during magnification.
9/5
magnification = 1.8
The Fluoroscopic Automatic Brightness Control (ABC) should be evaluated for quality
control when?
Anually
To ensure the component is properly working.
