RADT 1085 Unit 5 Test Questions
and Answers All Correct
Fluoroscopic Image Quality: Quantum Mottle - Answer-Blotchy, grainy appearance
Caused by insufficient radiation
Most common solution is to increase fluoro
tube mA
Advantages of FPIR over II-CCD: - Answer-• Less image distortion.
• Constant image quality over entire image.
• Improved contrast resolution.
• Rectangular image area coupled to similar
image monitor.
CCD converts - Answer-light pattern to electrical signal
Direct Capture - Amorphous Selenium System - Answer-- X-rays directly interact with
amorphous selenium
(photoconductor)
- No phosphor, so no light spread.
- Better spatial resolution
As focal point gets closer to input phosphor, .. - Answer-the size of the area of the input
phosphor decreases
Magnification mode results in: - Answer-• Better spatial resolution
• Better contrast resolution
• higher patient dose
- More x-rays per unit area are required
• "Mag Down" - Answer-- Few lp/mm (poorer spatial resolution)
- Poorer contrast resolution
- Less patient dose
"Mag Up" - Answer-- More lp/mm = improved spatial resolution
- Improved contrast resolution
- Greater patient dose
• Automatic Brightness Control (ABC)(ABS)
• Also known as Automatic Exposure Rate Control - Answer-- mA is automatically
increased
, - Improved contrast resolution
- Lower noise
- lower patient dose
Indirect - Cesium Iodide/Amorphous Sliicon - Answer-X-ray energy converted into
visible light in
scintillator layer.
• Light is converted into electrical charges by an
array of amorphous silicon photodiodes
• Read out by a TFT array.
Both Direct Capture Radiography Systems(CCD with amorphous silicon or Amorphous
Selenium) consist of - Answer-an (AMA) Active Matrix Array of detectors.
Pixel Pitch - Answer-Distance between the center of one DEL and the
center of the adjacent DEL
Smaller Pixel Size in a fixed receptor size = - Answer-Larger Matrix
Larger Receptor Size with fixed pixel size = - Answer-Larger Matrix
Receptor Conversion Efficiency - Answer-Ability of phosphor to emit as much light per
x-ray photon interaction
Receptor Absorption Efficiency - Answer-Percentage of x-rays absorbed
Receptor Detective Quantum Efficiency - Answer-Percentage of x-rays absorbed and
converted
_____ invented fluoroscope 1896. - Answer-Thomas Edison
Image Intensification Tube Phosphor Screen - Answer-X-rays to light photons
Image Intensification Tube Photocathode - Answer-Light photons to electrons
Image Intensification Tube Electrostatic lenses - Answer-Focus and accelerate
electrons
Condense image to increase brightness
Image Intensification Tube Output phosphor - Answer-• Electrons to light photons
• Zinc cadmium sulfide
Fluoroscopy X-Ray - Answer-
Fluoroscopic Image Intensifier •Image Intensifier (II) was developed in - Answer-1948
and Answers All Correct
Fluoroscopic Image Quality: Quantum Mottle - Answer-Blotchy, grainy appearance
Caused by insufficient radiation
Most common solution is to increase fluoro
tube mA
Advantages of FPIR over II-CCD: - Answer-• Less image distortion.
• Constant image quality over entire image.
• Improved contrast resolution.
• Rectangular image area coupled to similar
image monitor.
CCD converts - Answer-light pattern to electrical signal
Direct Capture - Amorphous Selenium System - Answer-- X-rays directly interact with
amorphous selenium
(photoconductor)
- No phosphor, so no light spread.
- Better spatial resolution
As focal point gets closer to input phosphor, .. - Answer-the size of the area of the input
phosphor decreases
Magnification mode results in: - Answer-• Better spatial resolution
• Better contrast resolution
• higher patient dose
- More x-rays per unit area are required
• "Mag Down" - Answer-- Few lp/mm (poorer spatial resolution)
- Poorer contrast resolution
- Less patient dose
"Mag Up" - Answer-- More lp/mm = improved spatial resolution
- Improved contrast resolution
- Greater patient dose
• Automatic Brightness Control (ABC)(ABS)
• Also known as Automatic Exposure Rate Control - Answer-- mA is automatically
increased
, - Improved contrast resolution
- Lower noise
- lower patient dose
Indirect - Cesium Iodide/Amorphous Sliicon - Answer-X-ray energy converted into
visible light in
scintillator layer.
• Light is converted into electrical charges by an
array of amorphous silicon photodiodes
• Read out by a TFT array.
Both Direct Capture Radiography Systems(CCD with amorphous silicon or Amorphous
Selenium) consist of - Answer-an (AMA) Active Matrix Array of detectors.
Pixel Pitch - Answer-Distance between the center of one DEL and the
center of the adjacent DEL
Smaller Pixel Size in a fixed receptor size = - Answer-Larger Matrix
Larger Receptor Size with fixed pixel size = - Answer-Larger Matrix
Receptor Conversion Efficiency - Answer-Ability of phosphor to emit as much light per
x-ray photon interaction
Receptor Absorption Efficiency - Answer-Percentage of x-rays absorbed
Receptor Detective Quantum Efficiency - Answer-Percentage of x-rays absorbed and
converted
_____ invented fluoroscope 1896. - Answer-Thomas Edison
Image Intensification Tube Phosphor Screen - Answer-X-rays to light photons
Image Intensification Tube Photocathode - Answer-Light photons to electrons
Image Intensification Tube Electrostatic lenses - Answer-Focus and accelerate
electrons
Condense image to increase brightness
Image Intensification Tube Output phosphor - Answer-• Electrons to light photons
• Zinc cadmium sulfide
Fluoroscopy X-Ray - Answer-
Fluoroscopic Image Intensifier •Image Intensifier (II) was developed in - Answer-1948
