CONTRAST MEDIA KEY EXAM QUESTIONS AND
CORRECT ANSWERS
What is the purpose of contrast media? - CORRECT ANSWERS it is used to visualize areas
within the body that other wise could not be seen well.
What are the 4 subject densities - CORRECT ANSWERS -Air: dark on film
-Fat: more dense and compact, alittle lighter than air
-Tissue/fluid: radiopaque, lighter
-bone: the lightest on an xray
Contrast - CORRECT ANSWERS different shades of black; gives you the picture
Factors affecting density - CORRECT ANSWERS -Absorption characteristics: air, tissue/fluid,
fat, bone
-technical factors
-image receptors
-processors
-contrast media
High atomic numbers - CORRECT ANSWERS -absorbs more xray photons; ex. bone #13.8,
Barium #56, Iodine #53
-increase in density
Low atomic number - CORRECT ANSWERS -absorbs fewer xray photons; ex. soft tissue
#7.4, Fat #6.3
-decrease in density
, -increase darkness on radiograph
Contrast media - CORRECT ANSWERS diagnostic agents that are instilled into the orifices
or inject into the vascular system, joint spaces and ducts to enhance subject contrast in
anatomic areas where low subject contrast exits.
The two classifications of contrast media - CORRECT ANSWERS -negative contrast agents
-positive contrast agents
attenuation - CORRECT ANSWERS the reduction in the intensity of an xray beam as it
passes through an object due to the absorption and scattering of photons
Negative contrast agent - CORRECT ANSWERS -air
-decrease attenuation of the xray beam
-increased density on radiograph
-radiolucent
-xray photons easily transmitted or scattered
-relatively lucent to xrays
-composed of low atomic number elements
-administered as gas (air) or gas producing crystals, tablets or soda water
-gas (air) appears darker on radiograph
positive contrast agents - CORRECT ANSWERS -barium and iodine
-increased attenuation of the xray beam
-decrease density on radiograph
CORRECT ANSWERS
What is the purpose of contrast media? - CORRECT ANSWERS it is used to visualize areas
within the body that other wise could not be seen well.
What are the 4 subject densities - CORRECT ANSWERS -Air: dark on film
-Fat: more dense and compact, alittle lighter than air
-Tissue/fluid: radiopaque, lighter
-bone: the lightest on an xray
Contrast - CORRECT ANSWERS different shades of black; gives you the picture
Factors affecting density - CORRECT ANSWERS -Absorption characteristics: air, tissue/fluid,
fat, bone
-technical factors
-image receptors
-processors
-contrast media
High atomic numbers - CORRECT ANSWERS -absorbs more xray photons; ex. bone #13.8,
Barium #56, Iodine #53
-increase in density
Low atomic number - CORRECT ANSWERS -absorbs fewer xray photons; ex. soft tissue
#7.4, Fat #6.3
-decrease in density
, -increase darkness on radiograph
Contrast media - CORRECT ANSWERS diagnostic agents that are instilled into the orifices
or inject into the vascular system, joint spaces and ducts to enhance subject contrast in
anatomic areas where low subject contrast exits.
The two classifications of contrast media - CORRECT ANSWERS -negative contrast agents
-positive contrast agents
attenuation - CORRECT ANSWERS the reduction in the intensity of an xray beam as it
passes through an object due to the absorption and scattering of photons
Negative contrast agent - CORRECT ANSWERS -air
-decrease attenuation of the xray beam
-increased density on radiograph
-radiolucent
-xray photons easily transmitted or scattered
-relatively lucent to xrays
-composed of low atomic number elements
-administered as gas (air) or gas producing crystals, tablets or soda water
-gas (air) appears darker on radiograph
positive contrast agents - CORRECT ANSWERS -barium and iodine
-increased attenuation of the xray beam
-decrease density on radiograph
