Purple
What absorbs the most x-rays?
a)Bone
b) Air
c) Metal
d) Fat
The part of the x-ray tube that emits electrons when heated and is made of a tungsten coil:
Filament
For V/D thoracic spine radiographs, you would measure at:
T13
(T13 is the tallest spot, to get the best exposure through the lungs and cranial abdomen)
A FFD (focal film distance) that is too short causes the radiographed image to:
Appear too dark
(The closer the target is to the film, the denser the radiation dose is to the film, and therefore darker on the image.)
The annual maximum permissible dose standard of radiation for anyone working with radiation is:
5rem
(The National Council on Radiation Protection and Measurements sets this standard for occupationally exposed individuals.)
When positioning an animal for radiographs, it is best to place the thicker portion of the patient toward ____ of the tube to produce a radiograph with uniform density.
The cathode
(This is due to the anode heel effect, which is the unequal distribution of the x-ray beam intensity. The higher intensity is at the cathode side of the beam and can better penetrate thicker objects.)
Which of the following would do the most to minimize scatter radiation is:
a) kVp is low
b) mAs is high
c) The collimator is open
d) The collimator is naroowed
D
(The collimator adjustment is one means of minimizing scatter radiation.)
The unit of radiation exposure rad stands for:
Radiation absorbed dose
The ultrasound term that refers to few echoes detected, and the area is a low-level gray compared with the surrounding tissue is:
HYPOechoic
Extremity radiographs should be taken with the film cassette:
On the tabletop
(Tabletop radiographs are preferred for object thickness up to 10cm. The inc. kVp needed to penetrate greater thickness causes greater scatter, so a grid is needed.)
Which views must be taken to properly perform a thoracic metastasis check on a patient with mammary adenocarcinoma?
R lat, L lat, V/D or D/V
(Three views should be taken to adeq. visualize the lung fields. A right and left lateral view are taken in addition to a VD/DV view as well. Anything less that this is considered incomplete by a veterinary oncologist.)
What is the purpose of an oblique projection?
To delineate an area that is normally superimposed over another
(An oblique projection is used to delineate an area that would normally be superimposed over another (e.g. the rt and lt sides of the mandible on a lateral projection of the skull)
When radiographing a long bone, it is important to:
a) Include as much of the abdomen as possible.
b) Include the joint proximal and the joint distal.
c) Measure over the thinnest area for the kilovoltage peak.
d) Include the long bone only, not the joints.
B
The primary difference between an OFA and a PennHIP evaluation is that:
a) PennHIP does not require special training of personnel.
b) PennHIP focuses on the degree of joint laxity using three views.
c) OFA focuses on the degree of joint laxity using three views.
d) OFA provides specific parameters for various breeds of dogs.
A
(Three views are taken for a PennHIP evaluation, and the primary predictor of susceptibility to hip dysplasia is the degree of joint laxity. Specific parameters are published for various breeds of dogs based on a large database. Veterinary staff must receive special training before performing the PennHIP procedures as s diagnostic tool.)
What is a latent image?
An unprocessed image (refers to silver halide crystals in film or on a digital cassette)
Which contrast study of the GI tract is monitored until the contrast medium reaches the colon?
Upper GI series
(This contrast study is used to evaluate the stomach nd small intestine. The contrast medium is administered orally, and films are made during transit of the contrast medium through the stomach and smll bowel into the colon.)
Rostral describes a location:
Toward the nose
A veterinary technician notes that a film is too dark, and there is minimal contrast (everything is gray). What is the most appropriate adjustment to be made to improve the quality of the repeat film?
Decrease kVp
(Exposure settings must be dec., because the film is too dark. If there is little distinction in scale between bone and soft tissue. (all of the tissue is gray), it indicates that the contrast may be improved by dec. the kVp.)
What is the PRIMARY source of scatter radiation?
(Scatter radiation originates from the patient as the primary bean strikes the first solid object and produces secondary radiation.)
Which contrast procedure listed generally uses both positive and negative contrast media?
a) Barium enema
b) Urethrography
c) Excretory urogram
d) Myelography
A
(A barium enema generally uses positive-and negative-contrast media to evaluate the large intestine.)
What landmarks should be included when radiographing the numerus?
Proximal landmark: shoulder joint
Distal landmark: Elbow
When naming a radiographic view, which of the following best describes a DPaMLO of the carpus?
a) The beam centers the dorsal/medial surface of the carpus and exits the palmar/lateral surface.
b) The beam enters the palmar/lateral surface and exits the dorsal/medial surface.
c) This is a dorsal/ventral view of the carpus.
d) This is a lateral/medial view of the carpus.
A
(The view is names by where the beam enters (first) and then exits the animal (last). For oblique views, one must provide more detail (i.e. dorsal vs. palmar and lateral vs. medial surface.)
What is the proper order of manual processing of x-ray film? (5)
Develop, rinse, fix, wash, dry
A lateral projection of a dog's shoulder is made. On the finished radiographic image, the manubrium and the trachea are superimposed over the joint space. How can the animal be repositioned to correct this?
a) Extend the head cranioventrally, and relax the caudal extension of the contralateral limb.
b) Extend the head caudodorsally, and draw the contralateral limb farther caudally.
c) Pull the limb being imaged farther, caudally.
d) Nothing; the shoulder cannot be repositioned without superimposing other structures over it.
B
(Extending the head caudodorsally moves the trachea off of the shoulder joint; extending the contralateral limb farther caudally moves the manubrium away from the shoulder joint.)
A pit bull is presented to the clinic for a GI study, because she consumed four sewing needles. Given her depression, anorexia, and abdominal tenderness, the doctor suspects that she has an intestinal perforation. You are asked to perform a positive contrast study. Which contrast agent is contraindicated in this circumstance?
(Barium is contraindicated, because if it passed through a perforation into the abdominal cavity, it would not be absorbed by the animal; instead it would remain there where it could result in an inflammatory response.)