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High spatial resolution and high contrast resolution require_____ noise and slow image receptors. .
Higher______ density reduces the contrast of the radiographic image.
What term is used to define the proper quantity for expressing image intensification.
a thin metal layer of cesium and antimony
In fluoroscopy, what provides better spatail resolution, better contrast resolution but at a higher patient dose.
Why is pulse progressive fluoroscopy necessary in digital fluoroscopy?
a. digital fluoroscopy is opereated in radiographic mode
b. to prevent thermal over loading
c. to reduce patient dose
a and b only
b and c only
a and c
a b c
The light intensity produced at the output phosphor compared to the light produced at the input phosphor is
increased by 50 to 75 times
On the television monitor, a bright spot is the result of
a. a brighter fluorescence of the phosphor due to a greater number of electrons leaving the electron gun
b. an increased video signal strength from the camera tube
c. an increased intensity of light reaching the camera tube from the output phosphor of the image intensifier
a and b
a, b and c
a b c
The output phosphor is
a)the same size as the input phosphor
b)larger then the input phosphor
c)smaller then the input phosphor
what is a
what is B
what is C
what is D
Conversion from remnant x-ray photons to light photons occurs @ __________ ?
Where is the electron beam focused?
Where are photo-electrons converted to visible light
As it pertains to digital radiography_______________ releases photo-electrons when struck by light photons and _________ releases light when struck by photo-electrons.
The ability to digitally record a small object, its accuracy and clarity is the definition of which of the following?
A decrease in the SNR will result in all of the following except:
A)Increased “fog” to the image
B)Reduced image quality
C)Less signal strength in the image
D)Improved image quality
All are advantages of television image monitoring of fluoroscopy except:
A)Multiple persons can view the image simultaneously
B)Electronic control of brightness level and contrast
C)Electronic image storage for later playback and image manipulation
D)Provides optimum spatial resolution
All of the following are advantages of flat panel image receptors except:
A)They are affected by external magnetic fields
B)There is no decrease in image quality around the image periphery
D)Improved contrast resolution over the entire image
How is the television image formed during fluoroscopy?
A)By transforming the photoelectrons from the photocathode of the Image Intensifier into x-ray photons
B)By transforming the remnant x-rays from the patient into a visible light image
c)By transforming the remnant x-rays from the patient into an electron beam
D) By transforming the visible light image of the Image Intensifie tube’s output phosphor into an electrical video signal
Which component of the digital fluoroscopy system converts the acquired electrical signals into a recognizable digital form for the display device?
D)Flat panel image display
Which portion of the image intensifier tube receives the remnant radiation from the patient?
Which term is defined as the ratio of the number of light photons at the output phosphor to the number of x-rays at the input phosphor?
Automatic brightness control is designed to compenstate for changes in
When the maginification mode is operated
A)a larger area of the input phosphor is used
B)patient dose is lowered
C)the electron focal point is closed to the input phosphor
D)the electron focal point is father away from the input phosphor
What camera tube is most often used
During digital fluoroscpy, the image receptor is the
B)image intensifier tube
C)TV camera tube
The sensitive input surface of the television camear tube is smaller than the output phosphor of the image intensifer tube.
True or False