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Image Acq. & Eval
Question | Answer |
---|---|
What is the single most important way to reduce the production of scatter radiation? | restricting the size of the x-ray field (Lange Radiography Prep Book, pg. 310) |
What is the main function of a grid? | absorb a large percentage of scatter radiation before it reaches the IR (Lange Radiography Prep Book, pg. 310) |
What is a focused grid? | grid with lead strips that are angled (Lange Radiography Prep Book, pg 312) |
What is a crossed grid? | grid that has another set of lead strips perpendicular to the first and prohibits the ability to angle the tube against them (Lange Radiography Prep Book, pg. 314) |
How do you determine grid ratio? | height of lead strip divided by the width of the interspace material (Lange Radiography Prep Book, pg. 314) |
What is the total filtration of the primary beam suppose to be? | 2.5mm Al (Lange Radiolgraphy Prep Book, pg. 317) |
What is considered inherent filtration? | glass envelope and collimator (Lange Radiography Prep Book, pg. 317) |
What is considered added filtration? | manufacturer determined if machine is using above 70 kVp (Lange Radiography Prep Book, pg. 317) |
What is the purpose of the anode heel effect? | placing the thicker body portion under the cathode end of the x-ray beam where the intensity is strongest (Lange Radiography Prep Book, pg. 319) |
When would you use a trough filter? | chest radiography (Lange Radiographyt Prep Book, pg. 328) |
Long scale of contrast shows displays what? | many similar image/ tissue densities that uses a higher kVp and larger field sizes (Lange Radiography Prep Book, pg. 338) |
Short scale of contrast displays what? | few, very different image/tissue densities that uses lower kVp and more "tigher" collimation (Lange Radiography Prep Book, pg. 338) |
mAs controls what on a radiographic images? | density (Lange Radiogaphy Prep Book, pg. 340) |
T/F: the scale of contrast is controlled by mAs? | False- kVp (Lange Radiography Prep Book, pg. 340) |
kVp controls what? | contrast (Lange Radiography Prep Book, pg. 340) |
What are the two types of AEC and where are they located? | ionization chamber: beneth the table top, above the IR phototimer: fluorescent screen underneath the IR (Lange Radiography Prep Book, pg. 351) |
The result of poor patient positioning using AEC will produce what type of image? | underexposed (Lange Radiography Prep Book, pg. 351) |
If you increase the focal spot size, what does it do to your blur and detail? | blur increases and detail decreases (Lange Radiography Prep Book, pg. 367) |
The effective focal spot size is always _____ than the actual focal spot size. | smaller (Lange Radiography Prep Book, pg. 367) |
What is a LUT? | matches the anatomic being imaged and functions to manipulate grayscale values to provide the appropriate grayscale (Lange Radiography Prep Book, pg. 397) |
Bit depth determines what? | grayscale (Lange Radiography Prep Book, pg. 334) |
Spacial resolution increases with __ pixel size, ___ pixel pitch, ____image matrix | small, small, large (Lange Radiography Prep Book, pg. 355) |
What factors affect spacial resolution? | OID, SID, focal spot size, patient body habitus, and motion (Lange Radiography Prep Book, pg. 358) |
What part of this film processing converts the latent image into a manifest image? | developer (Lange Review Radiography Prep Book, pg. 402) |
Window width controls what? | number of shades of grey (Lange Radiography Prep Book, pg. 377) |
Window level controls what? | brightness (Lange Radiography Prep Book, pg 377) |
What system is a true indirect flat panel system? | TFT (Lange Radiography Prep Book, pg. 378) |
How are x-rays converted in indirect systems? | x-rays are converted to light and then converted to electronic signal (Lange Radiography Prep Book, pg. 378) |
How are x-rays converted in direct systems? | x-rays are directly converted into electronic signal (Lange Radiography Prep Book, pg 378) |
What is the scintillator composed of in a TFT indirect system? | CsI or Gd2O2S (Lange Radiography Prep Book, pg. 378) |