Basic questions when evaluating a radiograph technique:
>film too light/dark?
An ____________ film is too light and ________ is too dark.
On a film with ______________ the anatomic parts are indistinct or imperceptible. Film too light.
__________ is considered when film is too light and anatomic silhouettes of interest are visible but not dark enough to be seen well.
Insufficient film density
When the film is too dark but the contrast is not affected
Excessive film density
A film with inadequate penetration, the anatomic parts are indistinct or imperceptible. Film is too light. How do we adjust?
> kVp increased by 10-15%
Insufficient film density gives us a film that is too light. The anatomic silhouettes of interest are visible but not dark enough to be seen well. How do we adjust?
>Density must be increased. mAs increased by 30-50%
Film is too dark, to fix this we must distinguish between too much density or too much penetration. The deciding factor is_______.
Primary factor used when evaluating an overexposed radiograph.
The contrast is used to determine if the overexposure is due to ________(__) or due to _________(__).
>too much density (mAs)
Bones will be gray if overexposure is due to _________(__). _______ due to too much ___ will have little effect on the contrast.
>too much density (mAs)
To be a diagnostic radiograph, a radiograph must have the correct _____ of contrast. For soft tissue, _______ is desired. For bone, ______ is desired.
______ decrease the quality of the radiograph, may lead to a misdiagnosis.
>artifacts: scratch, thumb print, chemical, dust
May require sedation or general anesthesia as well as positional devices. Primary goal is devising most suitable posture for animal so an accurate radiograph of the anatomical structures can be achieved.
When positioning the patient you must consider:
>welfare of patient
>minimize trauma to area of interest
>minimize radiation exposure to people assisting
_____ is used to measure the thickness in centimeters of the areas to be radiographed.
If not sure where to measure the animal, the measurement is made over _______.
How many views should be taken to ensure different perspectives?
at least 2 at right angles to each other
Exposing a large area around the object you are radiographing increases the amount of _________ which decreases the _________.
> scatter radiatoin
> radiographic contrast
Dry side of the darkroom should consist of:
Two types of hangers:
1. channel hangers
2. clip hangers
>will hold chemicals and water
>clips break. leaves holes in film. can damage other film
Wet side of the darkroom consists of:
>the developing tank and chemicals
>film drying area
______ can occur if safe light is too close to the work area, too much wattage, or has the wrong filter.
All solutions be kept at same temp, variation in temp can lead to __________, a mottled density on the finished film due to irregular expansion and contraction of the film emulsion
Two methods used to determine the developing time when doing manual developing:
1. time-temperature developing
2. sight developing
The developing time is determined by using the temperature chemicals