Diagnostic imaging Flashcards
What are the “joints” in the skull referred to?
Sutures. Sutures are fibrous bands of tissue that connect the bones of the skull. (In neonates, the sutures are open and allow for growth of the brain and skull)
Linear artifacts on a film are usually cause by what?
Grid.
The settings that affect exposure without changing contrast are ____
milliamperage (or mA) and exposure time. Increasing either will increase the exposure of the film.
Changing kilovoltage (kvp) changes the amount of ____
Contrast
What is a myelogram?
A diagnostic imaging test that uses contrast dye into the subarachnoid space and either xrays or CT to look for problems in the spinal canal, nerve roots, and other tissues.
mAs is a measure of the ____ ____.
Total exposure. It is the product of mA and time in seconds. (Generally, it is best to maximize the mA and minimize exposure time to decrease motion artifacts)
MRI compatible devices are made with non-ferromagnetic metals such as ____.
aluminum, titanium, brass, and “others”
Magnetic (or ferrous) metals consist of ___.
Iron, nickel, and cobalt. (INC.)
Invertebral disc spaces appear ____ towards the center of the film and ____ towards the end of the film.
Wider, Narrower
For ultrasound probes, higher frequency probes have ____(increased/decreased) image resolution and _____ (increased/decreased) penetrating ability relative to lower frequency probes.
Increased, decreased
Which 3 structures of the body are the most sensitive to radiation?
The lens of the eye, (and those with rapidly dividing cells) bone marrow, gonads (ew)
What is a Potter-Bucky diaphragm
A moving grid placed between the patient and the xray film that can be repositioned to reduce visual artifacts caused by secondary radiation
What is a grid
A series of short strips of lead that is placed over the cassette, absorbing all radiation that does not go between the strips
What would cause a developed xray to appear yellow?
Yellow radiographs are usually seen when the fixer solution is low, or fixation time is too short
What is the bisecing angle technique?
a technique used to prevent distortion when it is not possible to place the film parallel to the structure of interest and perpendicular to the xray beam (common in dentistry)
What is skyline view?
A technique used to decrease superimposition of structures, usually in an equine carpus
What is a DLMPO xray?
dorsolateral-palmaro/plantaromedial oblique
What is the metallic element on xray that turns black when exposed and run through the radiograph development process?
Silver. Film go into the developer first which reduces exposed silver halide into elemental metallic silver which is black.
Which trimester of pregnancy is the most important to follow radiation safety?
The first trimester (the first 3 months)
What is a pyelogram?
An intravenous pyelogram (IVP) is an xray examination of the kidneys, ureters, and urinary bladder using iodinated contrast material IV and excreted through the kidneys (particularly the upper urinary tract)
The fetal skeleton ossifies at ___-___days for a dog, and __-___ in the cat.
42-45 days for a dog, 35-39 days for a cat. The scapula/humerus/and femur develop first, then the ribs, then the teeth and toes
adjusting kilovoltage or kvp changes what?
kilovoltage affects Kontrast (higer kvp = LESS contrast)
Heartworm disease on xray causes ___ and looks like ___.
Right heart enlargement, and enlargement of pulmonary arteries. It looks like a “reverse D” on a VD.
What does the heel effect refer to?
The xray beam intensity declines toward the anode (or positive) side of the xray machine
For an xray vet tech, what is the maximum permissible dose of radiation they can receive in 1 year?
50 mSv.