VTNE: Diagnostic Imaging

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

-750 HU

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

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

110 V

Which of the following kV will produce more scatter and secondary radiation? a. 40 kV b. 60 kV c. 70 kV d. 110 kV

110 kV

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?

1460m/s

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

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

256 shades of gray

What is the speed of sound through air?

330 m/s

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

What is the speed of sound through bone?

4080 m/s

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

4MHz

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

546 ms

MRI machines produce noise in which of the following ranges?

60-90 dB

what is the typical kilovotage preset on a dental unit?

70kV

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

when obtaining a lateral projection of the skull of small animals, 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 impedance

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

Against the 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 of the following can occur if DNA is affected by radiation? A. Cell death B. Cell damage may be obvious, with portions of the DNA compromised C. Cell may display no immediate effects, but damage may have occurred internally that will affect the individual later, when mitosis occurs D. All of the above

All of the above

Which of the following can the piezoelectric crystal within an ultrasound probe do? A. Convert electrical energy into mechanical energy B. Convert mechanical energy into electrical energy C. Change shape in the presence of an electrical current D. All of the above

All of the above

Which of the following factors should all personnel understand about MRI machines? A. No loose metallic objects can be near the machine B. It consists of a strong magnetic field C. the magnet is always on D. Every patient/ employee should be screened for safety purposes E. All of the above

All of the above

All of the following people are allowed to view individual dosimetry reportsm, except: a. osha inspector b. owner of the practice c. only the employee exposed d. all team members

All team members

ALARA

As Low As Reasonably Achievable

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

Between 2 and 10 weeks gestation

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

Black

IV contrast used with CT imaging will help to view all of the following, except: (59 A. Veins B. Arteries C. Bone marrow D. Infection of the extremities

Bone marrow

Which of the following types of tissue absorb the most radiation? a. bone b. soft tissue c. fat d. bone, fat, and soft tissue absorb the same amount of radiation

Bones

Which particles have high linear energy transfer (LET) with low penetrability? (67) A. alpha particles B. Beta particles C. Gamma particles D. Both A and B

Both A and B (alpha particles and beta particles)

Which of the following correctly describes a CT image? A. A two-dimensional image B. A matrix of pixel or picture elements C. A three-dimensional image D. A matrix of voxels E. Both C and D F. Both A and B

Both C and D

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

Brightness

The amount of radioisotope used for each examination in a nuclear medicine study is measured in which of the following units? (100) A. kV B. mAs C. mCi D. MHz

C. mCi

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

CW Doppler

Caudocranial abbreviation

CdCr

To obtain a dorsoventral view of the abdomen of a rabbit, where should the center of the beam be focused? (6)

Center of the liver

Hypoechoic definition

Dark gray

Which of the following best describes the use for Doppler ultrasound? A. Doppler uses a motion mode that simultaneously creates a B-mode image while displaying the motion of the tissues over a two-dimensional scale B. Doppler is used to image the flow of blood and other liquids as well as to measure their velocity C. Doppler units display the different shades of gray D. None of the above

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

Which of the following radiographic terms describes the radiographic views distal to the carpus obtained by passing the primary x-ray beam from the dorsal direction to the palmar surface of the forelimb? (49)

Dorsopalmar

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

Dosimeter

Which of the following is the best view for detecting distal corner fractures? (99)

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? A. CT B. MRI C. Fluoroscopy D. Ultrasound

Fluoroscopy

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

Gadolinium

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

Grade 4

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

It allows adjustment of the gain at various depths

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

Kidneys

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

MRI

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

Medial oblique view

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

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

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? A Pieces or plates of metal used to correct the magnetic field within the magnet B. Coils or assemblies within the magnetic bore that enable the machine to create images in any plane C. Devices that receive radio-wave signals from a body part that is covered or contained by them D. None of the above

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

What is an isotope termed when it is radioactive?

Radioisotope

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

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

Tesla

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

The brightness of the image

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, and red indicates flow toward

What is a major safety concern with MRI machines?

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

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

To absorb the exiting remnant radiation

Which one of the following imaging modalities produces images without the use of radiation? A. X-ray B. Ultrasound C. Fluoroscopy D. CT

Ultrasound

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

Up and pointing rostrally

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

Varus deformity

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

Wipe with a glutaraldehyde-based disinfectant

Which of the following is considered to be a cardinal rule for radiation protection? Distance Time Shielding All of the above

all of the above

which of the following image receptors is used in dental imaging? Film Phosphor Plates Neither both

both film

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

comet tail

Which of the following best describes the word tomography? (62) A. Cut or section B. Whole C. Point of interest D. A series of boxes or individual shades of information

cut or section

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

dorsal recumbency

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

Which of the following locations is best for storing dosimeter badges?

dry cool place

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

every 2 years

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

hung by shoulders when not in use

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

lateral surface

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

lateral view

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

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

medial aspect

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

microconvex probe

In which imaging modality is Technetium 99m used?

nuclear medicine

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

radio waves

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

radionuclides

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

A biarticular fracture is also known as a:

slab fracture

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

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

the point at which the maximum blood velocity is reached

Describe the term fulcrum:

the point of interest

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

they vibrate