RTE 1401 Final Exam Questions and Answers |
2026 Update | 100% Correct.
Fixed mAs/ variable kVp chart
adjust kVp by multiplying by 2 (+/-) for every increment of ONE centimeter or inch of size
difference
Fixed KVP/ variable mAs chart
adjust mAs by multiplying (+) by 2 for every 4-5 centimeter or inch size difference
digital image quality factors
brightness, contrast resolution, spatial resolution, distortion exposure indicator, noise
brightness
intensity of light coming through monitor
contrast resolution
how well a system can display varying shades of gray
-affected by dynamic range
pixel depth
determines the number of shades of gray that can be displayed: 2 to the 14th power= 16,384
shades of gray
spatial resolution
measured in Lp/ mm
-2.5- 5 Lp/mm in digital imaging
,distortion
size & shape
effected by SID, OID, and alignment
exposure indicator
number displayed on the processed image to indicate the level of x-ray exposure received to the
digital image receptor.
-red, yellow or green
noise
random disturbance that reduces of obscures image clarity
-SNR and quantum noise
Signal to Noise Ratio (SNR)
The ratio of the speech signal (intended signal) to that of the background noise
-HIGH is ALWAYS best
quantum noise
lack of sufficient data (photons) - results in blotchy or mottled image. Increase mAs to fix
algorithms
complex math equations used to maintain image quality
Dynamic range
range of shades a digital system is capable of displaying as seen by the human eye
,exposure latitude
the range of exposures that can be used and still result in the capture of a diagnostic-quality
image
-DR has more than film-screen imaging
scotopic vision
night vision; uses rods of retina which are peripherally located
photopic vision
daylight vision; uses cones, centrally located
Image Intensifier
an electronic vacuum tube that converts beam of light to electrons, then back to light, increasing
the light intensity in the process
-brightens image up to 5,000 times brighter than conventional floural
-5 principal parts
5 principal parts of Image Intensifier
input phosphor screen, photocathode, electrostatic focusing lenses, accelerating anode*, output
phosphor screen
Dead man's switch
apply positive pressure to switch (not constant power)
input phosphor screen
, a 6"- 23" screen bonded to the curved surface of the flourscopy tube
-made of cesium iodide which acts as a scintillator
-converts XR to light
-curved to maintain distance to focal point
photocathode
emits e- when stimulated by light in a process called photoemission due to it being made of
cesium and antimony compounds
-bonded directly to input phospher
electrostatic focusing lenses
negatively charged plates that repel the e- to accelerate and focus them
-gradient in operation
output phosphor screen
2.5 cm screen located at the opposite end of the image intensifier that converts e- to intensified
light
-made of zinc cadmium sulfide
accelerating anode*
located at the neck of the intensifier near output phospher, it sets the e- stream in motion at a
constant velocity
Multifield Image Intensifier
multiple sizes of input screen; may be used to magnify the image
2026 Update | 100% Correct.
Fixed mAs/ variable kVp chart
adjust kVp by multiplying by 2 (+/-) for every increment of ONE centimeter or inch of size
difference
Fixed KVP/ variable mAs chart
adjust mAs by multiplying (+) by 2 for every 4-5 centimeter or inch size difference
digital image quality factors
brightness, contrast resolution, spatial resolution, distortion exposure indicator, noise
brightness
intensity of light coming through monitor
contrast resolution
how well a system can display varying shades of gray
-affected by dynamic range
pixel depth
determines the number of shades of gray that can be displayed: 2 to the 14th power= 16,384
shades of gray
spatial resolution
measured in Lp/ mm
-2.5- 5 Lp/mm in digital imaging
,distortion
size & shape
effected by SID, OID, and alignment
exposure indicator
number displayed on the processed image to indicate the level of x-ray exposure received to the
digital image receptor.
-red, yellow or green
noise
random disturbance that reduces of obscures image clarity
-SNR and quantum noise
Signal to Noise Ratio (SNR)
The ratio of the speech signal (intended signal) to that of the background noise
-HIGH is ALWAYS best
quantum noise
lack of sufficient data (photons) - results in blotchy or mottled image. Increase mAs to fix
algorithms
complex math equations used to maintain image quality
Dynamic range
range of shades a digital system is capable of displaying as seen by the human eye
,exposure latitude
the range of exposures that can be used and still result in the capture of a diagnostic-quality
image
-DR has more than film-screen imaging
scotopic vision
night vision; uses rods of retina which are peripherally located
photopic vision
daylight vision; uses cones, centrally located
Image Intensifier
an electronic vacuum tube that converts beam of light to electrons, then back to light, increasing
the light intensity in the process
-brightens image up to 5,000 times brighter than conventional floural
-5 principal parts
5 principal parts of Image Intensifier
input phosphor screen, photocathode, electrostatic focusing lenses, accelerating anode*, output
phosphor screen
Dead man's switch
apply positive pressure to switch (not constant power)
input phosphor screen
, a 6"- 23" screen bonded to the curved surface of the flourscopy tube
-made of cesium iodide which acts as a scintillator
-converts XR to light
-curved to maintain distance to focal point
photocathode
emits e- when stimulated by light in a process called photoemission due to it being made of
cesium and antimony compounds
-bonded directly to input phospher
electrostatic focusing lenses
negatively charged plates that repel the e- to accelerate and focus them
-gradient in operation
output phosphor screen
2.5 cm screen located at the opposite end of the image intensifier that converts e- to intensified
light
-made of zinc cadmium sulfide
accelerating anode*
located at the neck of the intensifier near output phospher, it sets the e- stream in motion at a
constant velocity
Multifield Image Intensifier
multiple sizes of input screen; may be used to magnify the image
