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Radt 465
Image acquisition and evaluation
Question | Answer |
---|---|
T/F Recorded detail and SID are directly related. | True |
What can grid interspace material be made of? | Aluminum and plastic fiber |
T/F Decreasing the field size will increase scatter. | False. It will decrease scatters |
T/F Increasing kVp will increase contrast scale. | False. kVp and contrast are inversely related. |
Ways to minimize motion unsharpness are... | Patient instruction, short exposure time and suspend respiration. |
When storing film in boxes you should store in which position? | Vertical |
What factors contribute to film fog? | The age of film, excessive exposure to safelight and processor chemistry. |
Xray photon energy is inversely related to what? | Photon wavelength |
How s grid ratio defined? | The height of the lead strip divided by the width of the interspace material |
What is the formula to determine the amount of image magnification. | Image size / object size = SID / SOD |
Chemical fog may be attributed to... | Excessive developer temperature, oxides developer, excessive replenishment |
What is the main difference between direct and indirect capture? | Direct capture/conversion has no scintillator |
What is the direction of electron travel in the X-ray tube is... | Cathode to anode |
What will improve spatial resolution if FOV stays the same? | Larger matrix |
The absorption of useful radiation by a grid is called... | Grid cutoff |
What types of shape distortion are there? | Elongation and foreshortening |
Examples of additive pathological conditions | Ascites, rheumatoid arthritis, pagets, pneumonia, atelectisis, CHF, edematous tissue |
What factors influences the production of scattered radiation? | kV level, tissue density, size of field |
A 15% decrease in kV accompanied by a 50% increase in mAs will result in what? | Shorter scale of contrast |
How are mAs and patient dose related? | Directly proportional |
What can the front of the image plate material be made of? | Carbon fiber and magnesium |
An increase in kV applied to the X-ray tube increases the what? | Exposure rate |
T/F A histogram illustrates pixel value distribution. | True |
What is the correct order of radiographic film processing? | Developer, fixer, wash, dry |
The reduction in xray photon intensity as the photon passes through material. | Attenuation |
Exposure rate will decrease with an increase in what? | SID |
A film/screen image exhibiting insufficient density might be attributed to what? | Inadequate kV and grid cut off |
What are the effects of scattered radiation on a radiograph if image? | It produces fog |
What are methods that help to reduce the production of scattered radiation? | Compression and beam restriction |
T/F Beam alignment, reproductability, and linearity are all tested as part of the QA program. | True |