Flashcards in The Chest Xray Deck (57)
What causes penetration and image formation in an Xray?
Density of the Object
What type of wavelength and frequency are X-rays?
Short wavelength high frequency
Adjusting what feature allows ticker and more dense tissues to be penetrated?
Increasing the force measured in Kilovolts
How is magnitude adjusted in an X-ray?
Adjusting the mass or the total number of photons emitted per unit time
What determines a good film when assessing an anterior view?
Faintly see vertebral disks through the mediastinum
Vasculature through the heart
Good inspiratory film count 9-10 ribs
What ribs are being seen on an anterior film?
Posterior ribs, the anterior ribs are penetrated
What determines a good film when assessing a lateral view?
The vertebral bodies get darker moving down the spine
Should see two sets of ribs (L and R)
Be able to see the sternum
Why might a physician purposefully order a film to be over or under exposed?
To assess pathology
What are the major factors that contribute to the density of an object?
What factors would cause less penetration on a chest X-ray film?
Increased thickness, atomic number and compactness
What factors would cause more penetration on a chest X-ray film?
Decreased thickness, anatomic number and compactness
What are the four body tissues that are radiologically distinguishable?
What items will show up white on an X-ray?
What items will show up black on an X-ray?
What items will show up gray on an X-ray?
What are the components of the cassette?
How does exposure affect the film?
Greater the radiation exposure the blacker the film
What is the purpose of the fluorescent screen?
Concerts the radiation (photon beams) to light photons that actually expose the film
What is the purpose of the grid system?
It improves contrast and detail by limiting scatter
How can the provider tell if the grid is improperly centered?
There may be whiteness seen outside of the chest wall
What is the best way to get a chest X-ray?
Why should the standing PA position be shot from the back?
What does the vertebral S axis refer to in a standing PA X-ray?
The S should be lined up between to the two clavicular heads at the level of T3
What does the term interface refer to when examining an X-ray?
The line of demarcation between tissues of different radiologic density.
Define the silhouette effect.
When tissues of similar radiographic density abut each other their interface cannot be visualized (same color on X-ray overlap each other, can't tell borders)
How does magnification affect the image on an X-ray film?
As the patient is moved away from the X-ray film the image on the film is magnified.
What is the concept of summation on an X-ray?
The larger the tissue, the lighter it looks on an Xray
How does summation change the appearance on an X-ray?
If there are three different shades of gray that overlap each other, the shade of gray creates is a summation of the overlapping tissues
What is a pleural effusion?
Fluid leaking into the pleural space between the lungs and chest wall