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Radiology Lecture Final
Crowder College Radiology Lecture Final
356
Veterinary Medicine
12/08/2011

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Cards

Term
To make an identical image, the large crystal will require what amount of radiation?
Definition
Less
Term
To made an identical image, the small crystal will require what amount of radiation?
Definition
More
Term
The detail of the large crystal would be described as?
Definition
Less detail
Term
The detail of the smaller crystal would be described as?
Definition
Greater detail
Term
Fast screen require a smaller or larger exposure?
Definition
Smaller
Term
Slow screens require a larger or smaller exposure?
Definition
Larger
Term
What is the primary purpose of an intensifying screen?
Definition
To reduce the amount of radiation needed to produce a radiograph
Term
Describe quantum mottle.
Definition
An artifact seen with extremely fast screens that are so so sensitive. Inconsistent fluoresence from the phosphor layer results in spotty, moth eaten appearance.
Term
T/F-Approximately 75% of the exposure recorded on a film is due to the light emitted from the intensifying screens.
Definition
False
Term
T/F--A cassette must not maintain close contact between the intensifying screens and the film.
Definition
False
Term
T/F--The primary function of the intensifying screen is to reduce the amount of radiation exposure required to produce a diagnostic radiograph.
Definition
True
Term
Faster screen speeds require a small exposure and produce less detail; slow screens require a larger exposure and produce greater detail.
Definition
True
Term
T/F--Screens must be cleaned regularly. Dirt and hair on the screen can cause radiographic artifacts.
Definition
True
Term
T/F--X-ray film is manufactured in only one speed and by one manufacturer.
Definition
False
Term
The conversion of x-radiation into visible light occurs via...
Definition
Intensifying screens
Term
To absorb backscatter, the back of most cassettes is lined with:
Definition
Lead
Term
Intensifying screens allow:
Definition
A lower kVp to be used
Term
The main advantage of today's rare earth coated intensifying screens is:
Definition
They have a higher x-ray to light conversion efficiency
Term
T/F--Non-screen film requires greater exposure
Definition
True
Term
A processed film that has not been exposed to ionizing radiation or visible light will appear:
Definition
Clear
Term
What are the appropriate storage conditions for radiographic film?
Definition
10-15C; 40% to 60% humidity; vertical
Term
What film-screen system is most commonly used in veterinary medicine?
Definition
Medium speed system
Term
What are the layers of the intensifying screen?
Definition
1) Protective coat
2) Emulsion
3) Reflective
4) Base
Term
What type of crystals are in the intensifying screen?
Definition
Phosphorus
Term
What are the layers in the x-ray film?
Definition
1) Protective coat
2) Emulsion
3) Base
4) Emulsion
5) Protective coat
Term
What type of crystals are in the x-ray film?
Definition
Silver halide crystals
Term
When radiographing a long bone, what should be included to ensure proper positioning? Give an example
Definition
The joint above and the joint below
Femur: Acetabulum and knee
Term
When radiographing a joint, what should be included to ensure proper positioning? Give an example including landmarks.
Definition
1/3 of the bone above and below
Elbow: 1/3 of the humerus and 1/3 of the radius and ulna
Term
In a cranial/caudal view of an extremity, which side of the cassette should the L/R marker be placed?
Definition
Lateral
Term
Long grey scale contrast is good for what two views?
Definition
Abdomens
Thorax
Term
Short grey scale contrast is good for what views?
Definition
Bones
Term
Describe how a V/D abdominal radiograph should be placed on the view box?
Definition
Head towards the top
The right side should be on the left as if you're looking at them
Term
What are the two questions that you have to ask when you are deciding on the quality of a radiograph?
Definition
1) Too light/too dark?
2) Is there adequate penetration?
Term
How do you decide if there is adequate penetration on a film?
Definition
If you can see the outlines of the organs visualized
Term
What is the difference between a one-time artifact and a repeating artifact? Give examples of each.
Definition
One-time: specific to that particular radiograph, i.e. wet hair, scratch on film
Repeating: Something wrong with the cassette
Term
What is the name of the instrument used to measure an area's thickness?
Definition
Caliper
Term
Why does the area or extremity of interest have to be closest to the cassette?
Definition
The further away it is from the cassette, the more it will be distorted.
Term
What steps would you take to prepare a patient for an abdominal radiograph?
Definition
1) Withhold food for 8-12 hours
2) Allow animal to defecate before taking film or give an enema
Term
Name three positional aids you can use to aid in patient restraint.
Definition
1) Gauze
2) Rope
3) Tape
Term
What is Sante's rule?
Definition
(2x thickness of body part being imaged)+40
Term
In regards to intensifying screens the statement is true. The larger the crystal, the more or less light is admitted. But, the larger the crystal, the detail of the image increases or decreases.
Definition
More
Decreases
Term
Does a fast intensifying screen require more or less exposure to produce an image?
Definition
Less
Term
What is the latent image on an x-ray film? When does it become visible?
Definition
The invisible image on a film that has been exposed to radiation, but not developed.
After it has been processed.
Term
What is the purpose of the 3 x 7 area on the corner of a cassette that blocks x-rays from the film?
Definition
To leave a place on the film to put the label
Term
When describing film speed, fast film has large or small silver halide crystals that require more or less exposure, but produces a grainy image with increased or decreased detail.
Definition
Large
Less
Decreased
Term
In manual processing, what are the contents of the three tanks?
Definition
Developed
Water
Fixer
Term
In film processing, what are the five steps to processing, in order?
Definition
1) Developer
2) Rinse
3) Fix
4) Wash
5) Dry
Term
Which crystal requires more radiation exposure to emit the same amount of light?
Definition
Small crystal
Term
Which crystal would produce a more grainy image?
Definition
Large
Term
Which crystal would be considered slow?
Definition
Small
Term
Which crystal would produce an image of great detail?
Definition
Small
Term
List four advantages of automatic processing.
Definition
1) faster processing time
2) easier
3) less contact with chemicals
4) fewer errors
Term
T/F--It is mandated by the Department of Natural Resources to recover the silver contained in exhausted developer.
Definition
False
Term
List the required information that must be included on a radiograph's label.
Definition
1) Patient name
2) Owner name
3) Date
4) Clinic name
5) R/L markers
Term
A chemical solution that converts the latent image on a film to a visable image by converting the exposed silver halide crystals to black metallic silver.
Definition
Developer
Term
A lightproof encasement designed to hold x-ray film and intensifying screens in close contact.
Definition
Cassette
Term
The process by which the unexposed sliver halide crystals are removed from the film and the gelatin is hardened.
Definition
Fixation
Term
A solution (usually water) used to remove excess developer solution before the film is placed in the fix tank.
Definition
Rinse bath
Term
A layer of radiographic film made of gelatin containing suspended silver halide crystals.
Definition
Emulsion
Term
The tendency of a luminescent compound to continue to give off light after x-radiation has stopped.
Definition
Afterglow
Term
Sheets of luminescent phosphor crystals bound together and mounted on a cardboard or plastic base.
Definition
Intensifying screens
Term
An artifact of faster screens that result in density variation due to random spatial distribution of the phosphor crystals within the screen.
Definition
Quantum mottle
Term
A compound of silver and bromine, chlorine, or iodine, all of which are in the halogen group of elements.
Definition
Silver halide
Term
A device made of lead strips embedded in a spacing material to absorb scatter radiation.
Definition
Grid
Term
Variation in normal size and shape of anatomic structures due to their position in relation to the x-ray source and film.
Definition
Geometric distortion
Term
The amount the exposure needs to be increased to compensate for the grid's absorption of a portion of the primary beam.
Definition
Grid factor
Term
To get more density on a film, you should do what to the kVp and mAs?
Definition
Increase either or both
Term
The grid with a ratio of 10:1 absorbs
Definition
More scatter radiation and require greater exposure factors than a 5:1 grid
Term
Grid cut-off can be described as
Definition
Incorrect use of the grid so that the grid absorbs more radiation than it should
Term
Elongation and foreshortening of anatomic structure are associated with?
Definition
Geometric distortion
Term
A table top (non-grid) technique is used to radiograph an
Definition
extremity
Term
To prevent geometric distortion when performing a radiograph, which of the following guidelines should be followed?
Definition
The primary x-ray beam should be perpendicular to the object of interest and the patient positioned parallel to the film.
Term
Table-top exposures can usually be made under what circumstance?
Definition
When the object of interest is less than 10cm thick.
Term
Extremity radiographs should be taken with the film cassettes...
Definition
on the table top
Term
Low kVp produces...
Definition
Short scale of contrast
Term
The number of electrons produced by the filament is controlled by which exposure setting?
Definition
mA
Term
When radiographing a distal extremity a _____ scale of contrast is best.
Definition
Short
Term
What would do the most to minimize scatter radiation?
Definition
Narrow the collimator
Term
The crystals of high speed screens as compared to similar type of screens are...
Definition
Bigger and there is less detail
Term
The main advantage of fast speed screens and films is that...
Definition
lower exposure factors can be used
Term
If using rare earth screens, what spectrum of light must the film be sensitive to?
Definition
Green range
Term
What can cause a series of parallel white lines on the developed radiograph?
Definition
The grid
Term
Most x-ray film cassettes now have what kind of screens that glow when irradiated?
Definition
Intensifying screens
Term
You are looking at a film that is totally clear except for a bit of black along the edges. Your film has not been...
Definition
Exposed to radiation
Term
The remaining silver halide crystals from exposed x-ray film are removed in the...
Definition
Fixer
Term
What would cause the image on a processed x-ray film to be fogged?
Definition
Film stored in an area of high room temperature
Term
Non-screen film would most likely be used to take which type of radiograph?
Definition
Dental
Term
T/F--Fast film requires more exposure by x-rays.
Definition
False
Term
T/F--Films should be stored in boxes, flat, in a horizontal position.
Definition
False
Term
An x-ray film exposed to x-ray or visible light radiation and developed would appear?
Definition
Black
Term
An x-ray film accidentally developed before exposure to radiation appears?
Definition
Clear
Term
A new x-ray film taken directly from the box appears?
Definition
Green
Term
What is the minimum distance in feet that a safelight in the darkroom should be away from the work site?
Definition
4
Term
If using both blue and green sensitive film, what type of safelight should you use?
Definition
Red
Term
The main purpose of x-ray developer is to...
Definition
convert the exposed silver halide crystals into black metallic silver
Term
What mA would you select if you want a 5 mAs and your time is set at 1/60th second?
Definition
300 mA
Term
What should be the maximum intensity of the bulb in a safelight in the developing room?
Definition
15 watts
Term
Safelight fogging on a radiograph appears as...
Definition
Diffuse grayish area
Term
The pH of the fixer chemicals is
Definition
acidic
Term
The purpose of the fixer is to...
Definition
Clear unexposed silver halide crystals from film
Term
The ideal temperature of the chemicals for manual processing is?
Definition
68F
Term
What increases radiographic density?
Definition
Increased mAs
Term
What radiograph should have the shortest scale of contrast?
Definition
Femur
Term
Where is the grid located?
Definition
Between the patient and the cassette
Term
Which grid ratio can absorb more scatter radiation?
Definition
8:1
Term
To prevent magnification and distortion of the object being radiographed, the patient must be...
Definition
As parallel to the film as possible and be as close to the film as possible
Term
The conversion of x-radiation into visible light occurs via:
Definition
Intensifying screens
Term
What are three legally valid methods of labeling a radiograph?
Definition
1) Lead impregnated tape
2) Lead marker
3) Photoimprinting label system
Term
Any body part exceeding this measurement requires the use of a grid to reduce fog-producing scatter radiation?
Definition
10cm
Term
According to the author of the book, when developing a variable kVp technique chart, kilovoltage should be increased or decreased by increments of ____ for each centimeter measurement up to 80 kVp.
Definition
2
Term
What condition may require decreasing the mAs to account for increased radiographic density?
Definition
Neonatal animals
Term
If a radiograph is too light after taking a view of the lateral abdomen, what change may be recommended?
Definition
Increase mAs 30%-50%
Term
Compared to the abdomen, how much mAs does a quality view of the pelvis require?
Definition
30-50% more
Term
A grid with a ratio of 12:1 will be used with the machine at your clinic. How does this affect the generation of your variable kVp chart?
Definition
Need to add 10-15 to the sum of Santes' rule.
Term
A radiograph in front of you appears dark. You note that the bones are gray. You are best to do what for the next radiograph?
Definition
Decrease kVp
Term
You are looking at a radiograph that appears gray overall. This is best described as a...
Definition
Low contrast film with many steps but few changes between each step
Term
You have taken a radiograph using 10mAs and 60 kVp. To double the radiographic density for a second film, you should use?
Definition
200 ma, 1/10th second, 60 kVp
Term
If a radiograph is too light and under-penetrated you should...
Definition
Increase kVp 10-15%
Term
If a radiograph is too dark and has adequate penetration you should...
Definition
Decrease mAs 30-50%
Term
If a film is too light and has adequate pentration you should...
Definition
Increase mAs 30-50%
Term
If a film is too dark and over-penetrated you should...
Definition
decrease kVp 10-15%
Term
When evaluating a film you note that the film is too light. You then determine that the film does not have adequate penetration. The best adjustment to make when repeating the film would be to...
Definition
Increase the kVp
Term
When altering mAs or kVp settings to improve a radiograph, what guidelines regarding incremental changes are appropriate when making adjustments?
Definition
kVp should be changed 10-15% and mAs should be changed 30-50%
Term
You note that a film is too dark. There is minimal contrast. What is the most appropriate adjustment to be made to improve the quality of the repeat film?
Definition
Decrease kVp
Term
The term dorsomedial-plantarolateral oblique is in reference to the?
Definition
Metatarsus
Term
The term dorsomedial-plantarolateral oblique means that the x-ray beam is directed at the...
Definition
Dorsal limb aspect and the film is against the lateral side of the limb
Term
The peripheral borders for an elbow radiograph are
Definition
1/3 of radius/ulna and 1/3 of the humerus
Term
List four factors that affect screen speed.
Definition
1) Crystal size
2) Thickness of phosphor layer
3) Reflective layer efficiency
4) Dyes in the phosphor layer
Term
To determine if an animal had an ununited anconeal process, the veterinarian would want you to x-ray the...
Definition
elbow
Term
The palmer surface of the forelimb refers to...
Definition
the caudal surface of the forelimb distal to the carpus
Term
When naming a radiographic view what best describes a DMPaLO f the carpus?
Definition
The beam eneters the dorsal medial surface of the carpus and exits the palmar/lateral surface
Term
Heavy lines on radiograph are most likely due to..
Definition
Roller marks from automatic processor.
Term
When problem solving the possible source of artifacts on film, a tech might attribute a yellowing of radiographic film to...
Definition
Incomplete washing of processing chemicals
Term
A technician notes that there are equally spaced, heavy lines on a radiographic film. What is most likely to have caused this artifact?
Definition
Grid out of focus
Term
The technique chart should be modified by increasing the mAs by 50% for which patients?
Definition
Ascites
Term
What is a dosimetry device and how does it work?
Definition
It's a badge, ring, card device that measures the amount of radiation exposure.
Term
What are the three ways that technicians are exposed to radiation?
Definition
1) Scatter radiation
2) Primary beam
3) Faulty equipment
Term
What is the upper limit of exposure that an occupationally exposed individual may receive according to state and federal regulations?
Definition
0.05 Sc/yr
Term
Scatter radiation depends on what three things?
Definition
1) The intensity of the beam
2) The composition of the structure being radiographed
3) Kilovoltage levels
Term
The most conclusive method used to inspect lead-lined gloves and aprons for cracks and defects is?
Definition
Taking a radiograph of it
Term
Ways to decrease the number of personnel in the radiology suite include?
Definition
Sedating patients
Term
Ways to increase the penetrating power of x-rays include:
Definition
Increasing kVp
Term
The mAs for 1000 mA and 1/10th second is?
Definition
100 mAs
Term
The source image distance...
Definition
must be considered every time the control panel is set
Term
One percentage of the energy produced at the anode is n the form of...
Definition
x-rays
Term
The temperature of the filament within the cathode is controlled by...
Definition
mA setting
Term
Which is a characteristic of x-rays?
Definition
The intensity increases as SID decreases
Term
The potential difference between the anode and the cathode is measured in?
Definition
Kilovolts
Term
A higher kVp setting allows for a _____ mAs and _____ exposure time.
Definition
Lower
Lower
Term
kVp describes the quality or quantity of the x-ray beam?
Definition
Quality
Term
mA describes the quality or quantity of the x-ray beam?
Definition
Quantity
Term
What is the best combination of the three radiology factors?
Definition
High kVp
Low mA
Short time exposure
Term
What is the standard SID or FFD?
Definition
40 cm
Term
What happens to the image in detail and intensity when the SID is decreased?
Definition
More detail, more intensity
Term
What happens to the image in detail and intensity when that distance is increased?
Definition
Less detail, less intensity
Term
To get a good quality spinal radiograph, two things must happen. What are they?
Definition
1) Spine parallel to the tabletop
2) Verterbral disc spaces perpendicular to the tabletop
Term
List two methods used to create a good quality spinal radiograph.
Definition
1) Positional aids
2) Manual extension
Term
What are the four views for cervical spine?
Definition
1) V/D extended
2) Lateral
3) Flexed
4) Hyperextended
Term
An important radiographic aid used during lateral cervical radiographs is?
Definition
A radiolucent positioner under the midcervical region
Term
Where do you center for a lateral T-L spine?
Definition
L1
Term
Where do you measure for a lateral T-L spine?
Definition
7th rib
Term
What are your cranial and caudal landmarks for a lateral T-L spine?
Definition
Cranial: xyphoid
Caudal: Last rib
Term
Where do you center a V/D T-L spine? Measure?
Definition
Center: T-L junction
Measure: 7th rib
Term
What are your cranial and caudal landmarks for V/D T-L spine?
Definition
Cranial: xyphoid
Caudal: last rib
Term
How many people are required to perform large animal radiology procedures?
Definition
Three
Term
What are the roles of each person?
Definition
Handler
X-ray cassette holder
Someone to work the x-ray machine
Term
What are the three sources of motion in large animal radiology?
Definition
1) X-ray cassette
2) X-ray machine
3) Animal
Term
Because of their low kVp output capabilities, what three areas of large animals are not capable of being taken with a portable unit?
Definition
1) Thorax
2) Abdomen
3) Pelvis
Term
List three retraint methods besides sedation used in large animal radiology?
Definition
1) Halter and rope
2) Twitch
3) Lift one leg (opposite of extremity being radiographed)
Term
List ten uses for diagnostic ultrasound in veterinary medicine.
Definition
1) Diagnose bladder wall inflammation
2) Visualize thyroid
3) Visualize kidneys
4) Visualize prostate
5) Visualize spleen
6) Check liver for changes in density that would indicate a problem
7) Detect pregnancy
8) Check for tendon issues
9) Guided fine needle aspirate
10) Echocardiography
Term
What is the difference between diagnostic ultrasound and therapeutic ultrasound?
Definition
Diagnostic produces an image using the differing intensities of returning echos while therapeutic is used to heat tissue and bone to promote healing.
Term
Name three organs/bones/structures that ultrasound is best designed for?
Definition
1) Kidney
2) Spleen
3) Prostate
Term
What is the difference in technology used between ultrasound and conventional radiology?
Definition
Ultrasound uses sound waves to produce an image while x-rays use ionizing radiation
Term
What is the difference in information gained between ultrasound and conventional radiology?
Definition
Ultrasound allows you to see density of tissue, gives real-time viewing of motion, more detailed images of fluid-filld organs and soft tissue as well as providing information about function. X-rays provide a 2D image of general outlines of organs
Term
How does therapeutic ultrasound work?
Definition
It uses sound waves to heat muscle/soft tissue by 3F, bone by 4F causing increased cellular metabolic rate, vasodilation, enhanced tissue healing and breakdown of scar tissue
Term
What are three circumstances where therapeutic ultrasound should be avoided?
Definition
1) Neoplasia
2) Over growing bones
3) Eyes
Term
Describe the difference between a high frequency transducer and a low frequency transducer.
Definition
Frequency used: High-increased, Low-decreased
Penetrating Depth: High-decreased, Low-increased
Resolution: High increased, Low decreased
Term
What is the difference between a pulse wave transducer and a continuous wave transducer?
Definition
Pulse contains one transducer that sends out a sound wave, then must wait for the echo before sending out another. Continuous has two transducers, so one can be sending out pulses while the other always listens for echos.
Term
Describe the appearances in the display modes of a ultrasound image.
Definition
A mode: Amplitude; spikes on a graph
B mode: Brightness; 2D image of grey-scale
M mode: Motion; continuous view of a thin slice of an organ over a period of time
Term
What is the importance of coupling gel?
Definition
Coupling gel eliminates air between the transducer and patient since air would bounce back the sound waves.
Term
Describe the positioning for a left lateral oblique film?
Definition
Patient in right lateral recumbancy with skull obliqued 30-40 degrees, mouth open
Term
Describe the labeling for a left lateral oblique film of the skull.
Definition
Label the mandible that is closer to the top of the film
Term
In ultrasound, air ____ sound.
Definition
Scatters
Term
_____ transmits sound with little attenuation or reflection.
Definition
Fluid
Term
Mineral and metals are highly ______.
Definition
Reflective
Term
Air and bone have_______ acoustic impedance.
Definition
High
Term
_______ is the forcing of substances (topical or injectable meds) through the skin and into the underlying tissue.
Definition
Phonophoresis
Term
The lateral oblique view of the tympanic bullae requires placing the _____side of the skull closest to the cassette.
Definition
Unaffected
Term
____ lateral recumbency for left obliques.
Definition
Right
Term
_____ lateral recumbency for right obliques.
Definition
Left
Term
A bladder stone is hyperchoic. What type of image does this project on the ultrasound monitor?
Definition
Bright white image
Term
A urine filled bladder is usually best classified as?
Definition
Anechoic
Term
Ultrasound term that means few echos are detected and the area is a low-level grey compared with the surrounding tissue?
Definition
Hypoechoic
Term
Which of the following best describes a high frequency ultrasound unit transducer?
Definition
Increase resolution and decreases penetration
Term
The best view for tympanic bullae is?
Definition
Open-mouthed rostrocaudal
Term
For a D/V view of the skull you should center the primary beam?
Definition
Between the lateral canthi on sagital crest
Term
A lateral skull radiograph should be...
Definition
done on anesthetized patients only
Term
A single piece of sound information related to the intensity of the signal
Definition
Echo
Term
Uniform number of echos throughout such as a normal liver or testicle.
Definition
Homogenous
Term
Misrepresentation of information such as enhancement or shadowing.
Definition
Artifact
Term
Without echoes, or the lack of density in a structure, such as fluid.
Definition
Anechoic
Term
Lesser number of echos when compared to surrounding tissue such as a tumor with necrosis
Definition
Hypoechoic
Term
The conversion of electrical energy to ultrasound or acoustic energy.
Definition
Piezoelectric effect
Term
The loss of intensity of the ultrasound wave as it travels through tissue.
Definition
Attenuation
Term
The lack of echos below a reflective area like bone or air because the sound waves do not penetrate and are reflected back up to the transducer.
Definition
Acoustic shadowing
Term
Tissue equal in appearance to that of surrounding tissues
Definition
Isoechoic
Term
The ability of a living tissue to resist or block the transmission of sound.
Definition
Acoustic impedance
Term
Lateral Skull
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: thickest point of the cranium
Center: lateral canthus of the eye
Cranial: tip of nose
Caudal: base of skull
Term
V/D skull
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: lateral canthi
Center: between lateral canthi
Cranial landmark: tip of nose
Caudal landmark: base of skull
Term
D/V skull
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: thickest point of cranium
Center: between lateral canthi
Cranial: tip of nose
Caudal: base of skull
Term
Describe the differences in patient prep for a large animal radiograph than a small animal radiograph.
Definition
Shoes should be removed
Overgrown hooves should be trimmed
Clean sole of foot and pack with radiolucent material
Make sure hair is clean and dry
Term
Name two positioning devices used in extremities of large animal radiology to compensate for the height of the primary beam exiting the unit.
Definition
1) Block
2) Manual cassette holder
Term
Long grey scale contast is good for what two views?
Definition
Abdomen and thorax
Term
Short grey scale contrast is good for what views?
Definition
Bone
Term
Motion is a common artifact in large animal radiology, give three patient examples of ways it can be managed.
Definition
1) Lift opposite leg of the one being radiographed
2) Lightly sedate
3) Use proper restraint techniques
Term
Which of the three exposure factors can be manipulated to control motion artifacts?
Definition
Time
Term
What is the perfect combination of exposer factors that is most effective in radiology?
Definition
Low kVp
High mA
Fast time
Term
What are two common causes of a radiograph that has turned yellow?
Definition
1) Improper storage
2) Age without the chemicals having been thoroughly washed off
Term
Describe correct positioning for an OFA V/D extended pelvis view. Include positioning, anatomy, and appearance of a finished film.
Definition
V/D in v-trough with hind legs extended and stifles luxated medially so that the patellas sit between the femoral condyles. Hind legs should be parallel to each other and to the cassette. Pelvis should look like a mirror image on each side with the tail taped flat between the legs. View should be from top of the ilium to past the stifle joint so film should include pelvis, femurs, and stifles. Finished film should look square.
Term
What steps would you take to prepare a patient for an abdominal radiograph?
Definition
Withhold food for 12-24 hours, give an enema one hour before radiographing and take for a long walk to allow for a good bowel movement before x-ray.
Term
Thoracic films are taken at what point in the respiratory cycle?
Definition
Peak inspiration
Term
Abdominal films are taken at what point in the respiratory cycle?
Definition
Pause at exhalation
Term
What is the advantage of taking a right lateral thorax?
Definition
Elongates the cardiac silhouette
Term
TO radiograph soft tissues like abdomens and thorax's, a specific combination of technique factors are required. What are they?
Definition
High kVp
Low mA
Fast time
Term
What is the advantage of taking a left lateral thorax?
Definition
Gives a better view of the lung field
Term
What information do BIPS provide?
Definition
motility of the GI tract
Term
What information do BIPS not provide?
Definition
View of intestinal lining or mucosal surfaces
Term
All artifacts appear as clear or white marks on film, except?
Definition
Crimping or folding of the film
Term
Positive contrast media are considered to be?
Definition
Radiopaque, which means it will be white on a processed film
Term
The tri-iodinated compound that is least irritating to the GI tissues and has less toxicity is the?
Definition
Meglumine diatrizoic salt
Term
The positive contrast compound that is not diluted by secrestions or absorbed through the intestines is?
Definition
Barium sulfate
Term
The veterinarian suspects a perforation of the small bowel in a 9 year old German Shephard and wishes to confirm her diagnosis via a special positive contrast study. She asks you to use what agent?
Definition
Tri-iodinated compound
Term
Angiography consists of a bolus injection of iodinated contrast media into the?
Definition
Vascular system
Term
An intravenous pyelogram is also referred to as a(n)?
Definition
Excretory urogram
Term
A specialy study that involves the use of a negative contrast media is?
Definition
Pneumocystogram
Term
What information can a BIPS study provide?
Definition
Information about gastric transit time
Term
When performing a double-contrast study of a cat's bladder the veterinarian expresses hematuria. She decides not to perform a double contrast study. Why?
Definition
She is concerned about vascular integrity and resultant room air embolism with the negative contrast agent
Term
A Newfoundland is presented to the clinic for an upper GI study. The veterinarian suspects an intramural tumor in the small intestine and requires excellent mucosal detail on the films. What contrast agent will most likely be selected?
Definition
Barium sulfate
Term
In large animal radiology, what is the purpose of raising the limb opposite to the limb being radiographed?
Definition
Restricts patient's movement
Term
How does spillage of contrast media on the cassette or tabletop cause artifacts?
Definition
Prevents x-rays from reaching the film properly
Term
When is a V/D frog leg pelvic view an appropriate choice?
Definition
Trauma
Term
A dog is lying in left lateral recumbancy for a pelvis radiograph. The right femur will be...
Definition
More magnified because of decreased FFD and increased OFD
Term
The femurs in a V/D hip dysplasia view appear foreshortened. This is likely due to not having the...
Definition
Femurs parallel to the table
Term
Which views must be taken to properly perform a throracic metastasis check on a patient with mammary adenocarcinoma?
Definition
Right and left lateral view and a V/D or D/V view
Term
Why is a right lateral view of the abdomen preferred over a left lateral view?
Definition
To allow better separation of the kidneys
Term
Thorax lateral
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: Caudal edge of the scapula
Center: Caudal border of the scapula
Cranial: Thoracic inlet
Caudal: Xiphoid process
Term
Thorax V/D
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: Caudal edge of the scapula
Center: Caudal border of the scapula
Cranial: Thoracic inlet
Caudal: Xiphoid process
Term
Thorax D/V
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: Caudal edge of the scapula
Center: Caudal border of the scapula
Cranial: Thoracic inlet
Caudal: Xiphoid process
Term
Abdomen Lateral
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: Last rib
Center: 2-3 fingers caudal to last rib
Cranial landmark: xiphoid process
Caudal back of the ischium
Term
Abdomen V/D
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: last rib
Center: 2-3 fingers caudal to the last rib
Cranial: xiphoid process
Caudal: back of the ischium
Term
Pelvis lateral
Measure?
Center?
Cranial landmark?
Top?
Caudal landmark?
Bottom?
Definition
Measure: greater trochanter
Center: greater trochanter
Cranial: 2-3 lumbar spine
Top: dorsal part of patient
Caudal: back of ischium
Bottom: mid-femur
Term
Pelvis V/D extended
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: greater trochanter
Center: greater trochanter
Cranial: top of ilium
Caudal: past stifle joints
Term
Front extremity: Radius/Ulna
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: at elbow or thickest part
Center: at midpoint of radius/ulna or at area of interest
Cranial: include elbow
Caudal: include carpus
Term
Front extremity-Lateral
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: at elbow or thickest part
Center: at midpoint of radius/ulna or at area of interest
Cranial: include elbow
Caudal: include carpus
Term
Rear extremity-Lateral Tarsus joint
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: tarsus joint
Center: mid-metatarsus
Cranial: 1/3 of the bone above
Caudal: end of phalanges
Term
Rear extremity-D/Pa tarsus joint
Measure?
Center?
Cranial landmark?
Caudal landmark?
Definition
Measure: tarsus joint
Center: mid-metatarsus
Cranial: 1/3 of the bone above
Caudal: end of phalanges
Term
Describe radiolucent.
Definition
Appears black or dark grey on finished film; negative contrast
Term
Describe radioopaque.
Definition
Appears white on finished film; positive contrast
Term
What is the advantage of using contrast medias?
Definition
It shows the lining of the mucosal surfaces and can show obstructions and perforations
Term
Give two examples of positive contrast.
Definition
1) Barium sulfate
2) Meglumine diatrozoic salt
Term
Give two examples of negative contrast.
Definition
1) Oxygen
2) Nitrous oxide
Term
What is a disadvantage or complication of using barium?
Definition
It is not absorbed by the body so if it enters the abdomen or chest it will stay there and can act as a foreign body.
Term
What is the disadvantage of using iodine preps?
Definition
They dilute as they pass through the GI system because they pull fluid from the tissues.
Term
What is a disadvantage or complication of using negative contrasts?
Definition
May cause an embolism
Term
Describe a double contrast study and where one might possibly be used?
Definition
Put positive contrast material into area of interest, then remove it and put negative contrast material in; bladder
Term
What are BIPS and what information do they provide?
Definition
Barium infused polyethelene; gastric transit time
Term
In what circumstance would you not want to take a V/D film?
Definition
If the animal is having respiratory distress
Term
What is the difference between and OFA film and a PennHip pelvic film?
Definition
OFA uses two views-lateral and extended V/D while PennHipp uses three-distraction, compression, and extended V/D to measure for joint laxity
Term
What is a physical property of x-rays?
Definition
They travel in straight lines
Term
As the wavelength of x-ray photons shortens, then energy of the x-ray beam will?
Definition
Increase
Term
X-rays are formed on the?
Definition
Anode
Term
When positioning an animal for radiographs it is best to place the thicker portion of the patient toward the _____ end of the tube to produce a radiograph with uniform density.
Definition
Cathode
Term
T/F-Portable x-ray units have a rotating anode tube and a single focal spot.
Definition
False
Term
As x-rays pass through materials, they have the ability to?
Definition
Cause some substances to fluoresce
Completely remove an electron from an atom, leaving the atom positively charged
Cause chemical changes that can kill cells
Term
During an exposure, electrons in the x-ray tube travel from the?
Definition
Cathode to the target
Term
To produce x-rays a great deal of energy in an x-ray tube is converted into heat. The ratio of heat generated to x-ray production is considered to be?
Definition
99:1
Term
X-rays are formed on the?
Definition
Anode
Term
A small filament and a small focal spot produces an image of?
Definition
Greater detail than a large filament
Term
The heel effect is going to be more noticeable with?
Definition
Larger film, shorter FFD, and lower kVp
Term
What transformer in an x-ray machine controls the temperature of the filament?
Definition
Step down transformer
Term
Regarding the production of x-rays in the x-ray tube, the
Definition
Cathode includes the filament and focusing cup
Term
When depressing the "prep" switch on a rotating anode x-ray machine, you are effectively...
Definition
Heating up the filament and spinning the rotating anode
Term
Full wave rectification means that?
Definition
120 pulses of x-rays are being produced per second
Term
The distance between the x-ray tibe and the film is the
Definition
Focal film distance
Term
Focal film distance is also know as the?
Definition
Source-image distance
Term
The focal spot is?
Definition
The spot on the tungsten target that te electron beam is aimed at
Term
A FFD that is too short causes the radiographed image to?
Definition
Appear too dark
Term
There is a gloved hand visible on a radiograph. This is...
Definition
A real concern because the hand has been exposed to radiation
Term
The cells that are the most susceptible to the hazards or ionizing radiation are?
Definition
All the cells of the body
Term
A sievert (Sv) is the?
Definition
Unit of radiation dose equivalent to the absorbed dose in tissue
Term
A radiation film badge worn at the collar level...
Definition
Monitors exposure of the thyroid gland and the lens of the eye
Term
If cracks are present in protective apparel, they appear _____ when radiographed?
Definition
Black
Term
The workplace program that has been developed to ensure radiation exposures are kept as low as possible is?
Definition
ALARA
Term
What does ALARA stand for?
Definition
As low as reasonably allowed
Term
The unit of absorbed does is?
Definition
Gray
Term
A person younger than ___ years should not be involved in radiographic procedures.
Definition
18
Term
One sievert (Sv) equals...
Definition
100 rems
Term
Images are displayed in real time in what radiography techniques?
Definition
Ultrasound and fluoroscopy
Term
Dosimetry badges should not be...
Definition
Left in the x-ray room
Term
Generally speaking when taking radiographs the veterinary technician should?
Definition
Maximize distance between herself and x-ray sources
Term
How often should chemical restraint be used during radiographic procedures?
Definition
As often as possible
Term
Scatter radiation on a film is more noticeable if there is...
Definition
Higher kVp, thicker patient and larger field size
Term
The acceleration of the electrons and their ultimate striking energy is determined by the...
Definition
kVp
Term
The exposure factor that is responsible for accelerating the electrons from the cathode to the anode is?
Definition
kVp
Term
The temperature of the cathode filament is controlled by what exposure factor?
Definition
mA
Term
Sante's ruled is used to calculate?
Definition
kVp
Term
When taking radiographs you should, whenever possible, use
Definition
Decreased exposure time, increased distance from radiation source, and increased shielding
Term
If you were going to decrease the focal-film distance from 100cm to 50 cm, what would your new mAs be if the old mAs was 16?
Definition
4 mAs
Term
Because of the relationship between mA and mAs, as you increase the mA you can?
Definition
Decrease the length of exposure so that there is less chance of movement
Term
When evaluating a film you note that the film is "too light". You determine that the film does not have adequate penetration. The best adjustment to make would be to?
Definition
Increase the kVp
Term
Who owns the radiographic record?
Definition
The veterinary practice
Term
How long legally should a radiograph be kept as part of the medical record?
Definition
5 years
Term
Can a radiograph be released to a client? Why or why not?
Definition
No, because it is a part of the medical record and is the legal property of the clinic that took it.
Term
Why must you take at least two views of every structure?
Definition
X-rays are 2D, so to get an accurate 3D representation you must have two views.
Term
List three methods that an x-ray tube will dissipate heat that is generated within the housing?
Definition
1) Oil
2) Rotating anode
3) ?
Term
Describe the heel effect.
Definition
Because of the angle of the anode, the x-ray beam is tronger towards the cathode end of the machine.
Term
Describe how the size of the focal spot will change the finished image.
Definition
The smaller the focal spot the more clear and defined the image.
Term
What are the two main advantages of using a beam limiting device like the collimator?
Definition
1) Avoid scatter
2) Clearer, sharper images
Term
What is the advantage of using three wave rectification?
Definition
Produces a more constant stream of electrons
Term
Non-image forming radiation that is scattered in all directions because of objects in the path of the x-ray beam.
Definition
Scatter radiation
Term
A device made of lead strips embedded in a spacing material, placed between the patient and the film, designed to absorb non-image forming radiation.
Definition
Grid
Term
The measurable difference between two adjacent densities
Definition
Contrast
Term
A device used to measure the thickness of anatomic parts.
Definition
Caliper
Term
The degree of blackness on a radiograph.
Definition
Density
Term
Related to thousands of volts. Describes the electrical potential between the cathode and the anode; it is responsible for accelerating the electrons from the cathode to the anode and relates the penetrating power of the x-rays.
Definition
Kilovoltage
Term
One thousandth of an amperage. A measure of electron current to the filament, which has a direct relationship to the number of x-rays being produced.
Definition
Milliamperage
Term
Effects of radiation that occur to the genes of reproductive cells
Definition
Genetic damage
Term
Damage to the body induced by radiation that manifests within the lifetime of the recipient.
Definition
Somatic damage
Term
Various methods used to measure radiation exposure to personnel.
Definition
Dosimetry
Term
The dose of radiation equivalent to the absorbed dose in tissue
Definition
Sievert
Term
The unit of absorbed dose imparted by ionizing radiations to matter
Definition
Gray
Term
A restricting device used to control the size of the primary beam
Definition
Collimator
Term
Part of a low energy circuit in the cathode that, when heated, releases electrons from their orbits.
Definition
Filament
Term
A recessed area where the filament lies, directing the electrons toward the anode.
Definition
Focusing cup
Term
A decrease of x-ray intensity on the anode side of the x-ray beam caused by the anode target angle.
Definition
Heel effect
Term
Partial outer shadow of an object being imaged by illumination
Definition
Penumbra
Term
The ability of a substance to emit visible light.
Definition
Flurescence
Term
A bundle of radiant energy
Definition
Quanta
Term
A visible photographic record on film produced by x-rays passing through an object.
Definition
Radiograph
Term
The distance between two consecutive corresponding points on a wave.
Definition
Wavelength
Term
A number of x-rays traveling together through space at a rapid speed
Definition
X-ray beam
Term
A positively charged electrode
Definition
Anode
Term
A negatively charged electrode
Definition
Cathode
Term
The process of changing alternating currects into a direct current.
Definition
Rectification
Term
A mechanism consisting of an anode and cathode in a vacuum that produces a controlled x-ray beam.
Definition
X-ray tube
Term
Name the five subject contrasts that can be seen on a radiograph.
Definition
1) Air
2) Bone
3) Metal
4) Liquid
5) Soft tissue
Term
What subject contrast has the most density?
Definition
Bone and metal
Term
What subject contrast appears the most black?
Definition
Air
Term
What subject contrast appears the most white?
Definition
Metal
Term
The grid with a ratio of 10:1 absorbs...
Definition
more scatter radiation and requires greater exposure factors than a grid of 5:1
Term
Grid cut-off can be described as?
Definition
Incorrect use of the grid so that the grid absorbs more radiation than it should.
Term
Elongation and foreshortening of anatomic structures are associated with?
Definition
Geometric distortion
Term
To prevent geometric distortion when performing a radiograph, what guidelines should be followed?
Definition
The primary x-ray beam should be perpendicular to the object of interest and the patient positioned parallel to the film.
Term
Low kVp produces?
Definition
A short scale of contrast
Term
What exposure factor increases radiographic density?
Definition
Increased mAs
Term
Where is the grid located?
Definition
Between the patient and the cassette