Section 10 - Diagnostic Imaging

Anything below what Hounsfield unit is displayed as black on CT imaging?

-750 HU

What is the typical wavelength of a medical x-ray?

0.05-0.01 nm

Modern CT scanners use multislice technology and are able to acquire image slices thinner than which of the following sizes?

1 mm

Pulse wave imaging can detect velocities up to a maximum of _____ m/s

1.4

Radiographs of joints must include which of the follwing?

1/3 of the bones proximal and distal to the joint

Which of the following kV will produce more scatter and secondary radiation?

10 kV

During an x-ray, a tabletop technique is most commonly used for exotic companion animals, except when the species' girth (waist) exceeds which diameter?

10-12 cm

What size power outlet is required to run a digital dental unit?

110 V

To what level of kV radiation are most lead aprons effective?

125 kV

Which of the following Hounsfield units on CT imaging appears as white?

1260 HU

What is the speed of sound through fat tissue?

1460 m/s

To obtain a dorsopalmar view of the interphalangeal joint, what should the primary beam angle be proximal to distal?

15-20 degrees

When using the shaded-surface display process with CT, which Hounsfield units should be selected to view bone?

160 HU

At what age in foals does the closure of the proximal growth plate of P2 occur?

18-30 weeks

What is the maximum number of focal points that are recommended for use in ultrasound?

2

To obtain a dorsopalmar view of the fetlock joint, the primary beam need to be angled ___ degrees proximal to distal?

20

The protective lead equipment required for wear during x-ray exposure can decrease the primary beam exposure by how much?

25%

Approximately how many shades of gray are incorporated into the display of an image obtained through ultrasound?

256 shades of gray

How long does it take for barium sulfate to travel from the stomach to the colon?

3 hours

How long should veterinary facilities maintain dosimetry reports?

30 years

What is the speed of sound through air?

330 m/s

What is the correct temperature for an automatic processor tank that is used to develop x-ray film?

35 C (95 F)

A computer tomography x-ray tube can rotate how many degrees?

360 degrees

When using a dental x-ray unit, the end of the cone should be positioned at ___ inches from the patient's anatomy.

4

Which of the following frequencies will allow for the deepest level of penetration in ultrasound?

4 MHz

What is the speed of sound through bone?

4080 m/s

When do fetal skeletons of small animals become visible on x-ray?

42-45 days

When does the soft tissue phase occur in nuclear medicine?

5-10 mins after injection

What is the maximum permissible dose of radiation a person can receive per year?

5000 millirems/year

Which repetition time shows the T1 decay response of the tissues during MRI?

546 ms

What is the half-life of the radioisotope Technetium Tc 99m used in nuclear medicine studies?

6 hours

To obtain a flexed lateromedial view of the carpus, the limb should be flexed how many degrees?

60 degrees

MRI machines produce noise in which of the following ranges?

60-90 dB

Horses have approximately how many carpal bones?

7

What is the typical kilovoltage present on a dental unit?

70 kV

When using computed tomography, what Hounsfield unit does blood have?

80 HU

What does the term pitch refer to in CT imaging?

A ratio between the table movement in mm and the CT slice thickness

Which of the following correctly describes a CT image?

A three-dimensional image and a matrix of voxels

The term ventral recumbency refers to the patient lying on the ____.

Abdomen

To obtain a craniocaudal view of the brachioantebrachial joint of a horse, how should the leg be positioned?

Abducted

When obtaining a view of the tympanic bullae, where should the centering of the image occur?

Above the base of the tongue and just below the palate, approximately at the commissure of the mouth

In the equation Z = pV used in ultrasound, what does the letter Z represent?

Acoustic velocity

All of the following organs are seen on ultrasound:

Adrenal glands, pancreas, gallbladder (not the lungs)

When obtaining a dorsopalmar view of the carpus, where should the cassette be held?

Against palmar aspect of the carpus

Where should the cassette be held when obtaining a dorsomedial-palmarolateral oblique view of the carpus of a horse?

Against the palmarolateral aspect of the leg

Which particles have high linear energy transfer (LET) with low penetrability?

Alpha and beta particles

What does the acronym ALARA stand for?

As low as reasonably achievable

What is the best exposure time for a thoracic radiograph?

At maximum inspiration

Which contrast is use for GI studies when perforation is not suspected?

Barium sulfate

Which time frame is the most critical for limiting radiation exposure to an unborn fetus of an employee?

Between 2-10 weeks gestation

When obtaining a foramen magnum projection of the skulls of small animals, where should the centering of the image occur?

Between the eyes

Where is the grid located in reference to an x-ray machine?

Between the patient and the cassette

How does cerebrospinal fluid appear on a true T1-weighted imaged of MRI?

Black

Which of the following types of tissue absorb the most radiation?

Bone

What caudal landmark is used when obtaining a lateral x-ray of the pelvis?

Border of the ischium

If pneumonia is suspected in small animals, which of the following radiographic views should be performed?

Both lateral and ventrodorsal views

Radiographs of long bones must include which of the following?

Both the joint proximal (above) and the joint distal (below) to the long bone

What is the correct definition of the abbreviation b-mode in ultrasound?

Brightness

Which of the following allows for measurements of very high blood flow velocities in ultrasound?

CW Doppler

Which of the following contains a filament consisting of a tightly coiled tungsten wire and is the site of electron generation in the x-ray tube?

Cathode

The abbreviation Cd in x-ray positioning refers to what?

Caudal

When positioning a lizard in right lateral recumbency before taking an x-ray, the left limbs are always ____ to the right limbs.

Caudal

For a lateral avian view, where would the left wing and limbs be positioned?

Caudally to the right wings and limbs

Which of the following radiographic terms describes the radiographic projection obtained by passing the primary x-ray beam from the caudal surface to the cranial surface of a structure?

Caudocranial

Which of the following is the correct abbreviation to perform a caudalocranial radiograph?

CdCr

Which of the following can occur if DNA is affected by radiation?

Cell death, immediate cell damage or cell damage seen later on

When obtaining a caudocranial view of the scapula of a small animal, where should the central ray be located?

Center of the scapula

What is the topographic radiographic landmark for the caudal cervical vertebrae?

Center of the spine of the scapula

To obtain a dorsoventral view of the abdomen of a rabbit, where should the center of the beam be focused?

Center over the liver

To obtain a whole body view of the abdomen of a rabbit, where should the center of the beam be focused?

Center over the thoracolumbar area

Which of the following is the best restraint to use in avian radiography?

Chemical restraint

Films that are properly collimated will have which of the following appearances?

Clear, unexposed areas on all four edges of the film

Lead shutters installed in the tube head of the x-ray machine are referred to as:

Collimeters

In a dorsoventral view on a small animal x-ray, which organ appears in the shape of a question mark?

Colon

Which of the following ultrasound artifacts will likely be produced when the sound wave strikes a metal object or a pocket of air?

Comet tail

A feature of digital radiography that is related to the bit depth of each pixel and the software that accompanies the digital-imaging system is referred to as:

Contrast optimization

Which of the following can the piezoelectric crystal within an ultrasound probe do?

Convert electrical energy into mechanical energy, convert mechanical energy into electrical energy, change shape in the presence of an electrical current

Film badges, TLDs, and OSL badges contain 3-4 elements for filtration. Which element monitors the highest level of exposure to radiation?

Copper

Which of the following are ways to determine if the animal is properly positioned in the lateral view?

Coxofemoral joints are superimposed

Which of the following is the correct abbreviation to preform a cranial radiograph?

Cr

The abbreviation CrCd refers to what?

Craniocaudal

Which of the following radiographic terms describes the view when the primary x-ray beam enters the cranial surface and exits the caudal surface of the patient?

Craniocaudal

Which of the following best describes the world tonography?

Cut or section

Digital radiography, CT, MRI and ultrasound are stored using a universally accepted format known as?

DICOM

Which of the following is the correct definition for the ultrasound term hydoechoic?

Dark gray

In which of the following circumstances should water-soluble organic iodides be avoided?

Dehydrated patients

Which of the following is considered to be a cardinal rule for radiation protection?

Distance, time, shielding

Which of the following best describes the use for Doppler ultrasound?

Doppler is used to image the flow of blood and other liquids as well as to measure their velocity

To obtain a craniocaudal view of the tibia of a small animal, that patient should be in which of the following positions?

Dorsal recumbency

When obtaining a caudocranial view of the humerus, in which position should the animal be?

Dorsal recumbency

Which of the following radiographic terms describes the radiographic views distal to the carpus obtained by passing x-ray beam from the dorsal direction to the palmar surface of the forelimb?

Dorsopalmar

Which of the following radiographic terms describes the view when the primary x-ray beam enters the dorsal surface and exits the ventral surface of the patient?

Dorsoventral

What view is required for the evaluation of the nasal passages?

Dorsoventral, laterl, rostrocaudal and open-mouth views

Meters to measure the rate of exposure is also known as:

Dosimeter

Which of the following is the correct abbreviation to perform a dorsopalmar radiograph?

Dpa

Which of the following is not an advantage of digital x-ray vs analog x-ray?

Elimination of damaging radiation

How often should x-ray equipment in a vet office be tested?

Every 2 years

Which of the following will cause a fogged film?

Exposure to excessive scatter radiation

Which of the following image receptors is used in dental imaging?

Film and phosphor plates

Which of the following is the best view for detecting distal corner fractures?

Flexed lateral view

Which of the following imaging modalities can cause radiation burns if the unit is too close to the skin and remains in exposure mode for too long?

Fluoroscopy

What causes grid lines on the entire film?

Focal-film distance not being in the range of the grid's focus

What occurs when the object is not parallel to the recording surface of an x-ray?

Foreshortening

What does MRI require to highlight injections, tumors, or vascular disease?

Gadolinium

Which of the following is not considered a physical restraint?

Gloved hands

Which grade level on the offification index for newborn foals does a closed metacarpal and metatarsal physes describe?

Grade 4

Which should be avoided when manually restraining a bird?

Grasping the patient around the neck

What is the caudal landmark for obtaining an abdominal x-ray in the lateral position?

Greater trochanter of the femur

Which of the following will help prevent motion artifacts?

High milliamperage

Before imaging the coffin bone, which of the following tasks should be preformed in preparation?

Hoof should be trimmed to the new sole level, the horseshoes need to be removed, the sulcus should be packed with radiolucent material

What is the term used to describe an area that indicates higher radiation has been emitted in nuclear medicine?

Hot spot

Which of the following is the best method for storing lead x-ray gowns?

Hung up by the shoulders when not in use

Which of the following locations is best for storing a dosimeter badge?

In a dry, cool place away from the x-ray beam

Which of the following should be done to ensure proper exposure?

Increase the kVp

Which of the following is not a form of barium sulfate that can be administered to patients?

Injectable

What does the TGC or time gain compensation allow on the ultrasound machine?

It allows adjustment of the gain at various depths

If the mA or exposure time is doubled, what happens to the film density?

It is doubled

How is gadolinium that is used in MRI excreted from the body?

Kidneys

Which of the following PPE must the handler wear when a patient is considered radioactive?

Lab coat, gloves, disposable boots and a dosimeter badge

When obtaining a lateral projection of the skull of small animals, where should the centering of the image occur?

Lateral canthus of the eye socket

The ability to distinguish between two objects that are adjacent to each other, yet perpendicular to the sound wave in ultrasound, is described as:

Lateral resolution

Which of the following is the best view for judging a major fracture dislocation and conformational abnormalities?

Lateral view

Which radiographic view provides the best accuracy for evaluating major fracture dislocation and conformational abnormalities in horses?

Lateral view

A grid is a series of thin, linear stripes made of what?

Lead

When viewing a lateral radiograph, the cranial part of animal is in which direction in relation to the illuminator?

Left

When obtaining an x-ray of a vomiting patient, which position is ideal?

Left lateral recumbency

When scanning in the sagittal plane, where is the cranial aspect of the patient's body displayed on the ultrasound monitor?

Left side of the monitor

The median plane divides the body into which of the following?

Left/right portions

Which of the following causes a black irregular border on one end of the film?

Light exposure while still in the box

The term oblique is generally used in reference to which of the following?

Limbs

When viewing a radiograph, which organ lies in the cranial abdomen between the diaphragm and stomach in small animals?

Liver

All of the following organs are normally seen on a radiograph:

Liver, kindey, bladder (not the pancreas)

Scatter radiation has a ____ wavelength than the primary beam

Longer

What does the color blue indicate on a nuclear medicine study?

Low activity

Which imaging modality is superior for demonstrating the brain and spinal cord?

MRI

For digital radiography, what does the postprocessing step of image manipulation allow?

Magnification, rotation, contrast adjustment

To obtain a lateromedial view of the femorotibial joint of the horse, the cassete should be placed against which surface?

Medial aspect

Which radiographic view provides the best option for detecting slab fractures in horses?

Medial oblique view

To perform an ultrasound in the intercostal region, which transducer would be ideal?

Microconvex probe

Which of the following factors should all personnel understand about MRI machines?

No loose metallic objects can be near the machine, it consists of a strong magnetic field, the magnet is always on, every patient/employee should be screened for safety purposes

The term rostral refers to toward the _____

Nose

In which imaging modality is Technetium 99m used?

Nuclear medicine

All of the following people are allowed to view individual dosimetry reports:

OSHA inspector, owner of the practice, only the employee exposed

For a mediolateral view of the tarsal joint of a horse, the cassette should be placed in which position?

On the lateral surface

Which of the following could cause a false diagnosis of a pneumothorax on a radiograph?

Overexposure of film

When obtaining a lateral view of the cervical vertebrae, which of the following techniques should not be performed?

Overextend the limbs caudally

Which of the following could be considered as negative-contrast agents used in radiography?

Oxygen, air, carbon dioxide

The only dental radiographic view that can be made with a true parallel technique is:

Parallel mandibular view

Which of the following is the correct order to process dental film?

Passed through the developer, wash, fixer, then wash again

To decrease magnification of an x-ray, which of the following would help?

Patients are positioned as close to the x-ray cassette as possible

Which of the following is the best technique to consider for an abdominal x-ray?

Peak expiration

Which type of magnet consists of two slabs of magnetic material facing each other?

Permanent magnets

Which of the following correctly defines the term shims in reference to MRI?

Pieces or plates of metal used to correct the magnetic field within the magnet

What element is found within the transducer of an ultrasound machine?

Piezoelectric ceramics

Which of the following radiographic terms describes the caudal surface of the hind limb distal to the carpus?

Plantar

What is the difference between color Doppler and power Doppler ultrasound?

Power Doppler is sensitive to slow flow and color Doppler indicates direction of flow

The term proximal refers to which of the following abbreviations?

Pr

What is the amount used to express the dose equivalent that results from exposure to ionizing radiation known as?

REM

What does the MRI unit use to manipulate hydrogen atoms in and out of an excited energy state?

Radio waves

The degree of blackness on a radiograph is described as:

Radiographic density

What is an isotope termed when it is radioactive?

Radioisotope

In dental radiographs, periapical disease appears as a:

Radiolucent area around the apex of the tooth

Atoms that emit particles and energy to become stable are known as:

Radionuclides

Which of the following terms is used to describe the white appearance on an x-ray?

Radiopaque

Which of the following are ways to determine whether the animal is properly positioned in the ventrodorsal view?

Rib and abdominal symmetry, wings of the ilium are symmetrical

When a patient is receiving an x-ray and is in the right lateral recumbent position, what marker should be used to denote the correct side?

Right

The number of detectors that are covered by the x-ray beam in CT scanning is known as which type of field of view?

Scan field of view

In MRI what are the various shades of gray referred to as?

Signal intensities

Which parts of a patient's body are considered radioactive after they have received the radioisotope?

Skin, hair, waste products

A biarticular fracture is also known as a:

Slap fracture

What is the cranial landmark for an x-ray of the thoracic vertebrae in the lateral position?

Spine of the scapula

To obtain a radiographic image of both temporomandibular joints of a small animal, which of the following is the best position?

Sternal recumbency

Which of the following is the most common medical magnet?

Superconducting magnets

For a ventrodorsal avian radiographic view, the keel (sternum) should be in which position related to the spine?

Superimposed

Exposing a reptile to cool conditions will cause what?

Temporary lethargy and immobility

What is the term used to describe a medical magnet's field strength?

Tesla

When using a V-trough, what needs to be measured before taking the x-ray?

The V-trough and the thickest portion of the body

What does the millimperage control on the x-ray machine affect?

The amount of radiation that is produced and the current to the cathode

What does the gain control knob adjust on the ultrasound machine?

The brightness of the image

When obtaining a radiograph, the thickest part of the area of interest is placed toward what?

The cathode end of the x-ray tube

When using color-flow Doppler in ultrasound, what do the displayed red and blue colors mean?

The colors show blood flow; blue indicates flow away, red indicates flow toward

Radiographic projections are named according to which of the following?

The direction in which the central beam anatomically enters the body parts, followed by the area of exit of the x-ray beam

Decreased radiographic density with poor contrast results from which of the following?

The film was underexposed

When obtaining a radiograph of the thoracic vertebrae, what level should be measured for the kVp setting?

The highest point of the thorax

The area of interest when obtaining an x-ray should be closest to what?

The image receptor

When obtaining a ventrodorsal x-ray of the thorax, what is the cranial landmark?

The manubrium

For a lateromedial view of the metacarpus of a horse, which surface should the cassette be on?

The medial aspect

For a dorsopalmar view of the metacarpus of a horse, which surface should the cassette be on?

The palmar aspect

For a dorsolateral-palmaromedial oblique of the metacarpus of a horse, on which surface should the cassette be placed?

The palmaromedial aspect

When an x-ray photon strikes an object, which of the following can occur?

The photon penetrates the object

Which of the following best describes the Nyquist point in ultrasound?

The point at which the maximum blood velocity is reached

Which of the following best describes the term fulcrum?

The point of interest

What is a major safety concern with MRI machine?

The potential projectile effect with metallic objects within the vicinity of the machine

Which of the following causes the entire film to be clear?

There was no exposure or the film was placed in the fixer before the developer

What happens to crystals within the ultrasound transducer when strong, short electrical pulses strike them?

They vibrate

What is the purpose of the foil backing found on dental x-ray film?

To absorb exiting remnant radiation

For what are grids used for on an x-ray machine?

To decrease scatter radiation and to increase the contrast on the radiograph

What does it mean to collimate the x-ray beam?

To limit the beam exposure just to the area of interest

You are looking at your dental radiograph and notice that the tooth is elongated. This happened because the beam was perpendicular to the:

Tooth

Which one of the following imaging modalities produces images without the use of radiation?

Ultrasound

Which of the following conditions results from uneven development of film?

Uneven chemical levels

What is a concern of exposure creep with the use of digial x-rays?

Unnecessary patient and personnel exposure

Dental film should be placed in the mouth with the dimple facing:

Up and pointing rostrally

Which radiographic view is best suggested for imaging the lungs?

VD

A deformity, in which the interior angle of the joint, viewed frontally, is <180 degrees, is known as what?

Varus deformity

IV contrast used with CT imaging will help to view all of the following:

Veins, arteries and infection of the extremities (cannot view bone marrow)

Before taking a radiograph of a patient, what is the proper way to obtain a measurement of the area of interest?

When the patient is in the position in which it is to be x-rayed

Which of the following is the proper way to disinfect an ultrasound probe?

Wipe with a glutaraldehyde-based disinfectant

The amount of radioisotope used for each exam in a nuclear medicine study is measured in which of the following units?

mCi

When using a Plexiglas tube to obtain an x-ray, which of the following should be adjusted?

the kVp should be increased