Download ANSWERS Chapter 1 1. Define digital radiography. Answer: Term

ANSWERS
Chapter 1
1. Define digital radiography.
Answer: Term used to reference two main imaging systems,
computed radiography and digital radiography (direct and
indirect capture).
2.
What is DICOM?
Answer: DICOM is an acronym for digital imaging communication
in media, an image file format that standardizes medical digital
images from imaging modalities from different manufacturers.
3.
Explain the purpose of a DICOM conformance statement.
Answer: Permits the user or vendor to determine if two devices
are compatible and can communicate by comparing their
conformance statements.
4.
What is the purpose of a PACS?
Answer: PACS is a picture archiving and communication system
which provides image capture, display, annotation, archive, and
communication functions allowing images to be viewed on multiple
computers.
5. Jpeg and tiff images have equal resolution to DICOM images.
True or False
Answer:
False
6. Define each of the following terms in relationship to a
display monitor:
Pixel
Dot Triad
Bit Depth
Matrix
Dot Pitch
Resolution
Answer: Pixel is a basic picture element.
Dot Triad is a grouping of one red dot, one green dot,
and one blue dot that makes up a pixel.
Bit Depth describes the number of bits used to store
information about each pixel of an image and determines
how many levels of gray or color that can be generated.
Matrix is a rectangular or square table of numbers that
represents the pixel intensity being displayed on a
monitor.
Dot Pitch is the measurement of how close the dots are
located to one another within a pixel.
Resolution is the number of pixels in a monitor’s
display. As the dot pitch becomes smaller, the
resolution improves and the greater the number of pixels
in an image, the higher the resolution. The higher the
resolution, more information can be displayed.
7.
The aspect ratio is determined by measuring the front of the
monitor display diagonally from one corner to the other.
True or False
Answer:
False
8. What are the two main advantages of computed radiography?
Answer: CR cassette can be used in a similar fashion to a filmscreen cassette and no major change to the existing x-ray
equipment is required.
9. Define spatial resolution.
Answer: The amount of detail in any image
10. Direct and indirect digital radiographic detectors have an
increased detective quantum efficiency (DQE) over computed
radiographic systems.
True or False
Answer:
True
11. The effect of electronic and quantum noise is commonly
referred to as signal-to-noise ratio. A higher quality image
consists of more signal and more noise.
True or False
Answer: False
Chapter 2
1. What is a radiographic intensifying screen?
Answer: A device that changes the x-ray beam into visible light
in a process called luminescence.
2.
Name the four basic layers of an intensifying screen.
Answer: Protective coating, phosphor layer, reflective layer,
and base.
3. Spectral emission refers to the color of light produced by a
particular intensifying screen. True or False
Answer:
True
4. Define spectral sensitivity and spectral matching.
Answer: Spectral sensitivity refers to the color of light to
which a particular film is most sensitive. Spectral matching is
choosing and matching the spectral sensitivity of film with the
spectral emission of the intensifying screen. Mismatching will
reduce the speed of the screen-film system.
5. What is the effect of image noise in a film-screen receptor
system?
Answer: Image noise reduces image contrast and causes the image
to have a grainy appearance.
6. What are the main similarities between digital and filmscreen radiography. Name at least four.
Answer:

DR panel, CR cassette, and film-screen cassette are all
imaging receptors

CR, indirect DR, and film-screen use phosphors to
capture x-ray energy and convert to light

Detective quantum efficiency (DQE) is important in all
three.

Image noise affects the appearance of the image in DR,
CR, and film-screen.

Image quality is affected by geometric factors

Grid is equally important in absorbing backscatter
radiation to improve image quality
Chapter 3
1. Name the four main components of a radiographic system.
Answer: X-ray tube, table, generator, and method of image
capture
2. What are the primary factors involved in producing an image?
Answer: Source Image Distance, milliampere, exposure time, and
kVp
3. The tungsten cathode is positively charged.
Answer:
True or False
False
4. When is the small filament used in imaging?
Answer: Small filament is used when imaging smaller extremities
and bones of the head when measurement is below 10 cm in
thickness.
5. Due to the anode heel effect, thicker body parts, like the
cranial abdomen, should be positioned on the anode side of
the x-ray tube. True or False
Answer:
False
6. Who invented the fluoroscope?
Answer:
Thomas Edison
7. Define fluoroscopy and name at least two imaging procedures
where it is particularly useful.
Answer: Dynamic or real time imaging. Fluoroscopy is used for
esophagrams, myelography, collapsing trachea imaging, gastric
emptying studies, and cardiac vascular imaging.
8. Name the two types of radiation responsible for exposing film
or a digital receptor.
Answer:
Primary and secondary or scatter radiation.
9. What two devices can be used to reduce the effects of back
scatter radiation?
Answer:
Grid and collimator
10. Kilovolt peak (kVp) controls the quality and penetrability of
the x-ray beam as well as contrast. True or False
Answer:
True
Chapter 4
1. Film processing is as important as technique and positioning
in a making a quality radiograph. True or False
Answer:
True
2. The darkroom, automatic or manual, should be wiped clean
weekly to minimize artifacts on film.
True or False
Answer:
False.
The darkroom should be wiped clean, daily.
3. Film developing is a chemical process therefore the
developer, rinse, fixer, rinse, and wash temperatures should
be the same. True or False
Answer: True
4. What is the optimal developer temperature for manual
processing?
Answer:
200C or 680F
5. What causes reticulation?
Answer: Using a higher than recommended developer temperature
followed by placing a film in too cool fixer will make the
film’s emulsion swell and thicken unevenly, causing it to slip
off the film base, creating a wrinkled appearance called
reticulation.
6. Why are silver recovery cartridges required in automatic film
processing?
Answer: Silver is a heavy metal so its disposal is regulated by
local and state agencies.
7. It is important to use the correct safelight filter in all
darkroom safelights based on the spectral sensitivity of the
film being processed. True or False
Answer: True
8. Radiographs are part of the patient’s medical record, giving
ownership and responsibility for those records to the
practice that produced them. True or False
Answer:
9.
True
Describe the effect of poor film-screen contact and list the
most common causes.
Answer: Poor film-screen contact is usually seen as a localized
area of unsharpness somewhere on the radiographic image. It can
be caused by worn contact felt, bent or broken hinges or
latches, warped screens resulting from excessive moisture, and
foreign matter under the screen.
10. Define screen lag and its cause.
Answer: Intensifying screens may luminesce in two ways,
fluorescence or phosphorescence. Fluorescence refers to the
ability of phosphors to emit visible light only while exposed to
x-rays. Phosphorescence occurs when screen phosphors continue to
emit light after the x-ray exposure has stopped. This is also
referred to as screen lag and will cause general overall fogging
of the radiographic image and degrading the scale of contrast in
the radiographic image. Screen lag is generally due to old worn
out screens.
Chapter 5
1. What is an imaging artifact?
Answer: An artifact is any unwanted optical density on an image
that does not properly show the anatomic area of interest being
examined.
2. When do film artifacts occur?
Answer: An artifact can occur when the film is exposed,
processed, handled or stored, either before or after processing.
3. Fogging, quantum mottle or noise, and nonparallel collimation
are some of the more common artifacts seen in digital
radiography. True or False
Answer:
True
4. What are the contributing factors for fogging in digital
radiography?
Answer: High kVp, no grid or inadequate grid efficiency,
inadequate collimation, increased part size or tissue density.
5. What particular artifact occurs in both film-screen and
digital radiography, producing a similar appearance on the
image? What is its cause and how is it decreased or
eliminated?
Answer: Quantum mottle or quantum noise. It is caused by
inadequate exposure and can be corrected by increasing mAs and
sometimes by adjusting kVp, as well as collimating.
6. What causes the nonparallel collimation artifact?
Answer: The nonparallel collimation artifact is caused by not
centering the anatomic region of interest to the center of the
DR panel. In DR, collimation edges must be parallel to the sides
of the imaging plate or there is a decrease in resolution.
Chapter 6
1. What are the three main advantages for using positioning
aids?
Answer: They decrease the need for manual restraint, reduce
repeat exposures to correct poor positioning, and reduce
radiation exposure to the patient and holders.
2. Care should be taken when using alternative restraint
techniques. Never leave a sedated restrained animal
unattended. True or False
Answer:
True
3. Why is the sand in a sand bag divided to each side of a
patient’s neck as an alternative restraint technique?
Answer: The full weight should never be on sensitive areas like
an airway.
Chapter 7
1. Who was the first American fatality of radiation exposure?
Answer: Clarence Dally, Thomas Edison’s assistant.
2. When was the first radiation dose limiting recommendations
made to protect radiation workers and the public?
Answer:
1931
3. With DR imaging, it takes 10-30% more radiation exposure to
produce a single DR image than a conventional film-screen
radiographic exposure. True or False
Answer: True
4. Safe operating procedures for a veterinary facility should
include:
a.
b.
c.
d.
protective lead apparel and radiation dosimetry badges
positioning aids
good technique chart
all of the above
Answer: d
5. What is the ALARA concept?
Answer: Radiation exposure in the workplace should be As Low As
Reasonably Achievable.
6. Lead aprons, gloves, and optional thyroid shields should be
0.5 mm thick lead equivalent. True or False
Answer: True
7. What is the occupational exposure limit a worker may receive
annually?
Answer: Annual 50 mSv(5000 mrem)
Chapter 8
1. To become proficient in radiography, one must learn basic
positioning views, correct positional terminology, required
patient preparation, and methods of restraint. True or False
Answer: True
2. When positioning a right or left lateral view of the thorax,
the right or left anatomic lead equivalent markers should be
placed within the collimated field
a.
b.
c.
d.
e.
f.
dorsally
ventrally
in the anatomy
in the axillary region
b & c
b & d
Answer: f
3. When positioning lateral view of the spine or pelvis, the
right or left anatomic lead equivalent markers should be
placed in the collimated field
a.
b.
c.
d.
e.
dorsally
ventrally
in the anatomy
in the axillary region
a & c
Answer: a
4. When positioning DP, CdCr, or CrCd view of an extremity, the
right or left anatomic lead equivalent markers should be
placed in the collimated field
a.
b.
c.
d.
medially
laterally
in the anatomy
a & c
Answer: b
5. In some states, manually restraining a patient is against
state regulations. True or False
Answer: True
6. Describe the types of horizontal beam views.
Answer: Horizontal beam views are views taken with the patient
in lateral, dorsal or ventral recumbent positions or with the
patient standing in lateral, dorsal or ventral standing
positions. Horizontal beam views called lateral decubitus views
can be used for visualization of free air in the abdomen and
pleural effusion in the thorax. They are also used for imaging
trauma patients when spinal fractures are suspected or even
fractures of the extremities. Horizontal beam views for
mediastinal masses are taken with the patient held upright in a
VD position.
Chapter 9
1. Two lateral projections of the scapula may be needed to
completely visualize the scapula, one for the body of the
scapula and a second lateral projection for the neck of the
scapula. True or False
Answer:
True
2. For extremity views, the measurement should be taken
a.
b.
c.
d.
Mid long
Over the
Over the
Over the
bone above joint
joint most near the area of interest
middle of the area of interest
thickest part of the area of interest
Answer: d
3. What shoulder projection is used to visualize the
supraspinatus tendon for calcifications?
Answer: Bicipital groove projection
4. Hyper-flexed lateral projections of the elbow are taken when
an ununited anconeal process is suspected. True or False
Answer: True
5. What projections are required to evaluate the elbow joint by
OFA?
a.
b.
c.
d.
450 lateral, only
900 lateral and CrCd
Hyper-flexed lateral
b & c
Answer: c
Chapter 10
1. For the lateral view of the pelvis, the patient is placed in
a lateral recumbent position with the affected side down. The
down femur is
a. Super-imposed beneath the up femur
b. Pulled cranially and the up femur is pulled caudally to
separate the legs
c. Positioned in a neutral position which means it is
slightly pulled cranial with the stifle flexed, as if the
patient were standing. The upper femur is pulled caudally
to separate the legs
d. None of the above
Answer: c
2. TPLO views of the stifle require both the stifle and tarsal
joints to be flexed 900 and included in the field of view.
True or False
Answer:
True
3. Most common routine views of the pelvis are:
a.
b.
c.
d.
Lateral, VD frog leg
Lateral, VD with legs extended
VD with legs extended, only
None of the above
Answer: b
4. OFA requires the following view(s) to be taken for
evaluation.
a.
b.
c.
d.
Lateral, VD frog leg
Lateral, VD with legs extended
VD with legs extended, only
None of the above
Answer: b
5. The PennHip imaging series to evaluate the hips is the most
accurate hip screening method available and can be safely
performed on dogs as young as 16 weeks of age by certified
PennHIP veterinarians and veterinary technicians, only.
True or False
Answer: True
Chapter 11
1. Spinal imaging requires careful positioning. The divergence
of the x-ray beam and the importance of imaging the
intervertebral disc spaces require the spine to be as
parallel to the table top as possible. True or False
Answer: True
2. Flexion and extension views of the cervical spine
a. Are taken only under the direct supervision of the
clinician
b. Do not require sedation
c. Are taken only when fracture or luxation is suspected.
d. None of the above
Answer: a
3. When positioning the patient for the lateral projection of
the cervical spine, the forelimbs are
a.
b.
c.
d.
Pulled cranially and secured
Left in a neutral lateral position
Pulled caudally and secured
None of the above
Answer: c
4. Where should the measurement be taken for the lateral and VD
projections of the thoracic spine?
a. Over the caudal ribs
b. Over the thickest part of the area of interest
c. Over the shoulders
d. None of the above
Answer: b
5. For the lateral view of the lumbar or LS spine region, the
hind limbs should be
a. Pulled caudally
b. Left in a neutral position
c. Positioned with the down leg pulled cranially and the up
leg pulled caudally
d. None of the above
Answer: a
Chapter 12
1. When evaluating the heart, DV and right lateral projections
of the thorax are taken. True or False
Answer:
True
2. If a patient is in respiratory distress or if a diaphragmatic
hernia is suspected, a VD projection is taken first.
True or False
Answer: False. A DV projection should be taken first when a
patient is in respiratory distress and a lateral projection
should be taken if a diaphragmatic hernia is suspected.
3. The most common routine view(s) for a soft tissue neck
a. Lateral and VD views to include the area between the TMJs
and the thoracic inlet
b. Lateral view to include the area between the TMJs and the
thoracic inlet
c. Lateral, oblique, and VD views to include the area between
the TMJs and the thoracic inlet
d. None of the above
Answer: b
4. Views of the thorax are taken on inspiration and views of the
abdomen are taken on expiration. True or False
Answer: True
5. For abdominal imaging, a long scale of contrast is preferred.
True or False
Answer: False
6. Flexed Leg Lateral view of the abdomen is taken
a.
b.
c.
d.
To visualize the caudal abdomen
On inspiration
To visualize the urethra
None of the above
Answer: c
Chapter 13
1. General anesthesia or heavy sedation is preferred for most
imaging studies of the head. True or False
Answer: True
2. When positioning a patient for the lateral projections of the
skull, what positioning aid should be used to keep the head
in a true lateral position?
Answer:
Foam wedge
3. For oblique views of the mandible, the degree of angulation
is dependent upon the shape of the dog’s head. True or False
Answer: True. A brachycephalic breed may only need 20o obliquity
whereas a dolichocephalic or mesaticephalic breed may need 30o.
The goal is to minimize any superimposition from the opposite
mandibular arcade.
4. Both left and right lead anatomic markers should be used for
each oblique projection of the cranium for bullae, mandibular
and maxillary arcade imaging. Placement of the markers is
dependent upon the imaging exam being performed.
True or False
Answer: True.
Chapter 14
1. Masking tape is the preferred tape for use in avian imaging.
True or False
Answer: True. When removing masking tape from wings of adult
birds, always remove the tape in the same direction the feathers
are pointing. Extra care is needed when using tape to restrain
during imaging of baby birds. Placing small additional masking
tape to cover the adhesive side of the tape actually covering
the wing will still permit effective restraint and not hurt the
feathers. Using a Plexiglas bird board during imaging is
recommended, particularly when chemical restraint is not an
option.
2. Why do avian imaging exams require smaller exposure factors
than small mammals or reptiles?
Answer: Avian cortices are significantly thinner.
3. What is an easy method of restraint when performing imaging
exams on nonpoisonous snakes?
Answer: Place the snake in a cloth bag, plastic tube, or box.
4. Chemical restraint is preferred when imaging small mammals to
prevent injury to both the patient and the holder.
True or False
Answer: True
Chapter 15
1. To better visualize soft tissue structures or organs,
positive or negative contrast enhanced imaging exams are
performed to assist the small animal practitioner in
diagnosing and treating illnesses in the small animal
patient. True or False
Answer: True
2. What are the most common contrast imaging exams performed in
a small animal practice? Name at least three.
Answer: Gastrointestinal tract (esophagram, gastrogram, upper
and lower intestinal studies); genitourinary tract
(cystourethrogram, IVU, vaginogram); vascular (angiogram,
lymphangiogram, venogram); spinal canal (myelogram,
epidurogram); fistulogram.
3. What are the two most common radiopaque contrast media agents
used to opacify low-contrast tissues in the body?
Answer: Iodine and barium.
4. What are the advantages of non-ionic contrast agents over
ionic contrast agents?
a. Fewer side effects permit more concentrated and greater
volumes of contrast to be used which improves
visualization of a structure or organ
b. Dilutes more slowly and to a lesser extent resulting in
sharper contrast borders for an increased length of time
c. Safer than ionic contrast agents
d. All of the above
Answer: d
5. What types of side effects and reactions are caused by ionic
contrast agents?
Answer: Acute renal failure, ECG changes, respiratory arrest,
peripheral vasodilatation, nausea, and vomiting
6. What is the weight-volume barium sulfate suspension typically
used for stomach and small intestinal tract imaging?
Answer: 30-60% weight-volume
Chapter 16
1. If an esophageal, gastric, or intestinal perforation is
suspected, an oral ionic or nonionic contrast media agent
should be used to opacify the structures. True or False
Answer:
True
2. What oral contrast agent can cause pulmonary edema if
aspirated?
Answer: Oral ionic contrast media agents such as Gastrografin or
MDGastroview
3. Fluoroscopic or dynamic imaging of the esophagus is
significantly helpful in evaluating
a.
b.
c.
d.
Esophageal and cricopharyngeal function
Strictures
Foreign bodies
None of the above
Answer: a
4. The excretory urogram, often called an intravenous urogram or
pyelogram, consists of two main phases. What are the two
phases?
Answer: Nephrogram phase and the pyelogram phase.
5. Positive contrast cystography is used to provide mucosal
detail and to visualize calculi and wall masses.
True or False
Answer: False. Positive contrast cystography is used to
visualize bladder position and the integrity of the bladder
wall.
6. Urethrography can be done antegrade or retrograde.
True or False
Answer: True. The antegrade or voiding cysto-urethrogram is
performed post positive contrast cystography.
7. What is a retrograde vaginourethrogram?
Answer: A contrast study performed to examine the vagina,
cervix, and urethra to look for ectopic ureters, vaginal
strictures or masses, and vaginal or urethral tears.
8. Myelography is a contrast study used to examine the spinal
cord by injecting nonionic contrast media into the
subarachnoid space to identify:
a.
b.
c.
d.
Protruding disk material
Spinal cord compression
Vertebral abnormality or mass
All of the above
Answer: d
9. Define fistula.
Answer: A fistula is a draining tract exiting at the skin’s
surface from an abscess or organ. Fistulas can be caused by
foreign bodies or sequestra associated with osteomyelitis