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Image production
Image Production
Question | Answer |
---|---|
What type of factors are brightness and gray scale in terms of image quality? | visibility factors (Lange Prep pg.325) |
What are the two types of geometric factors? | spatial resolution and distortion (Lange Prep pg.325) |
What is the most important variable in x-ray imaging? | the patient (Lange Prep pg.326) |
What are the three prime factors in radiography? | mAs, kV, and SID (Lange Prep pg.326) |
What refers to the various body tissue densities and thicknesses, which results in differential absorption of the x-ray beam? | subject contrast (Lange Prep pg.327) |
mAs is ___________ proportional to receptor exposure | directly (Lange Prep pg. 327) |
As ____________ is increased, more electrons are driven to the anode with greater speed and energy | kV (Lange Prep pg. 329) |
What three factors have effect on the production of scattered radiation? | beam restriction, kV, and thickness of part (Lange Prep pg. 331) |
What is the ratio between the quantity of useful photons transmitted through the grid and the quantity of scattered photons transmitted? | selectivity (Lange Prep pg.338) |
For patient protection purposes, what is the required minimum filtration of the primary beam? | 2.5-mm Al equivalent (Lange Prep pg.341) |
Atelectasis and Paget's disease are what type of pathologic conditions? | additive (Lange Prep pg.342) |
Osteoporosis and emphysema are what type of pathologic conditions? | destructive (Lange prep pg.343) |
True or False: Protective filtration has no effect on receptor exposure | True (Lange Prep pg.344) |
True or False: Generator type impacts receptor exposure | False (Lange Prep pg.344) |
The anode heel effect has little impact on _____________ imaging. (digital/analog) | digital (Lange Prep pg. 346) |
What is the two-dimensional picture element? | pixel (Lange Prep pg.346) |
What is the term for the number of bits required to describe the number of gray levels that each pixel can take on? | bit depth (Lange Prep pg.347) |
The window level corresponds to image ____________ | brightness (Lange Prep pg.348) |
The window width corresponds to the _____________ | shades of gray (Lange Prep pg.348) |
What are the two types of AEC's? | ionization chamber and phototimer (Lange Prep pg.354) |
As the matrix size increases, pixel size ____________, and spatial resolution increases. | decreases (Lange Prep pg.362) |
What is the typical matrix size for chest radiography? | 2048x2048 (Lange Prep pg.363) |
What is also referred to as sharpness? | spatial resolution (Lange Prep pg.364) |
OID is _________ related to magnification | directly (Lange Prep pg.366) |
SID is _________ related to magnification | inversely (Lange Prep pg.366) |
Where is the effective focal spot the largest in size? | the cathode end (Lange Prep pg.370) |
True or False: The effective focal spot os always smaller than the actual focal spot according to the line-focus principle. | True (Lange Prep pg.372) |
What type of x-ray generator will produce the greatest voltage ripple? | single-phase, full-wave rectified (Lange Prep pg.418) |
Diagnostic x-rays are generally associated with a _________ frequency and a __________ wavelength. | high ; short (Lange Prep pg.418) |
What device is used to change AC to an unidirectional current? | a solid-state diode (Lange Prep pg. 418) |
The electron cloud that forms on the cathode end of the x-ray tube is the product of a process called what? | thermionic emission (Lange Prep pg.432) |
In which part of the radiographic circuit can the x-ray tube be found? | secondary circuit (Lange Prep pg.444) |
What percent voltage ripple is associated with a three-phase, 12- pulse-rectified generator? | 4% (Lange Prep pg.444) |
What is located between the secondary coil of the high-voltage transformer and the x-ray tube? | rectifiers (Lange Prep pg.444) |
In an __________ conversion detector, x-rays are converted to light scintillations, and light is converted to electric signals. | indirect (Lange Prep pg.459) |
With a __________ focal spot, the focal point is farther from the output screen. | small (Lange Prep pg.471) |
What refers to the consistency of x-ray tube output over a series of exposures? | reproducibility (Lange Prep pg.503) |
What affects HVL? | kV and filtration (Lange Prep pg.502) |
What type of radiation happens when a high-speed electron that has an energy of at least 70 keV encounters a tungsten atom within the anode and ejects a K-shell electron, leaving a vacancy? | Characteristic radiation (Lange Prep pg.402) |
Which interaction contributes to image fog and poses radiation hazards to personnel in flouroscopy procedures? | Compton scatter (Lange Prep pg.405) |
Which layer of the PSP is responsible for directing emitted light toward the CR reader? | reflective layer (Lange Prep pg.399) |
What are the types of shape distortion? | elongation and foreshortening (Lange Q&A pg.175) |
What results in foreshortening of the radiographic image? | the part and IR are not parallel (Lange Q&A pg.199) |
A change in the actual focal spot will affect a change in what? | it will produce greater image resolution and sharpness (Lange Q&A pg.211) |
What computer function corrects for exposure errors? | rescaling process (Lange Q&A pg.211) |
A ____________ terminates the exposure if the AEC fails. | backup timer (Lange Prep pg.440) |
_______________ refers to the percentage drop from maximum voltage each pulse of current experiences. | voltage ripple (Lange Prep pg.444) |
What is the most common type of AEC? | ionization chamber (Lange Prep pg.444) |
____________ filtration included the glass envelope, and the oil coolant/insulation | inherent (Lange Prep pg.430) |
What is the anode made out of? | molybdenum or graphite (or both) (Lange Prep pg.422) |
What side of the x-ray tube is the negative electrode? | the cathode (Lange Prep pg.422) |
Wavelength and frequency are ___________ related | inversely (Lange Prep pg. 406) |
This is also called "Braking" radiation" | Bremsstrahlung (Lange Prep pg.402) |
Bremsstrahlung accounts for what percentage of all radiation of the x-ray beam? | 70-90% (Lange Prep pg. 402) |
What is a type of shape distortion? | magnification (Lange Prep pg. 364) |
Grid absorption of the useful beam is termed ________? | cutoff (Lange Prep pg. 358) |