Diagnostic Imaging Flashcards by Karyssa Hiller

What are the imaging modalities, and which ones require a specialized veterinary clinic?

Radiographs (x-rays)
Ultrasound
Thermography

’ Specialized veterinary clinic:
‘ Nuclear Scintigraphy (bone scan)
‘ Computed tomography (CT)
‘ Magnetic Resonance Imaging (MRI)

How well did you know this?

Not at all

Perfectly

What are radiographs used for?

Use x-ray to assess internal structures

Lameness uses:
Fractures, OA, OCD, osteitis, luxation, etc.

How well did you know this?

Not at all

Perfectly

What are the concerns of radiographs?

radiation exposure

How well did you know this?

Not at all

Perfectly

What are the five basic opacities in a radiograph?

Gas (dark gray to black)

Fat

Fluid or soft tissue

Bone-mineral

Metal (white)
□ Foreign bodies
□ Contrast agents - barium, iodine

How well did you know this?

Not at all

Perfectly

Describe radiograph contrast

X-ray beams are variably attenuated
§ Some are stopped, some get through

What determines final image
§ Type of tissue
§ Thickness of tissue
§ Energy of x-ray beam

Contrast radiography
§ Adding barium or iodine = + contrast
§ Adding gas = - contrast

How well did you know this?

Not at all

Perfectly

What is a summation?

An area of increased radiopacity (whiteness) occurring when two overlapping objects are in path of x-ray beam and are not in contact with one another

How well did you know this?

Not at all

Perfectly

What is a silhouette?

Margins of two objects cannot be distinguished because of similar opacity and margins are in contract

How well did you know this?

Not at all

Perfectly

What is film?

○ Analog gray scale
§ Continuous scale from black to white
○ Blackest = gas, fluid = radiolucent
○ Whitest = dense bone, metal = radiopaque

How well did you know this?

Not at all

Perfectly

What are the components of a digital radiograph?

Composed of discrete shades of gray

If there are enough “shades” then scale appears continuous

Most digital systems have 1000+ shades, making it possible to change grayness (lighten and darken image)

How well did you know this?

Not at all

Perfectly

What are the different radiographic views?

Lateral-medial (lateral): Flexed

Dorso-palmar/plantar (DP)

Angled: Skyline (carpus and navicular), DP 65 degrees

Obliques: DMPLO, DPLMO

How well did you know this?

Not at all

Perfectly

What is this view

flexed lateral of the carpus

How well did you know this?

Not at all

Perfectly

What is this view?

skyline of the carpus

How well did you know this?

Not at all

Perfectly

What is this view?

Navicular skyline

How well did you know this?

Not at all

Perfectly

What is this view

DP 65

dorsopalmar

How well did you know this?

Not at all

Perfectly

What is this view?

dorsomedial and plantarolateral surface: DLPMO

dorsolateral plantaromedia surface: DMPLO

How well did you know this?

Not at all

Perfectly

What does an ultrasound do?

Study These Flashcards

Use sound waves to assess soft tissue

Used for heart, reproduction, abdomen, and musculoskeletal systems

Lameness uses: Tendons, ligaments, intrasynovial issues and injections

What are the concerns with ultrasound?

Study These Flashcards

artifacts, expertise

How do Ultrasounds work?

Study These Flashcards

sound waves

travel through some mediums better than others

see white when sound wave cannot get through, black when it can

air = white = hyperechoic

fluid = black = hypoechoic

What is this called?

Study These Flashcards

comet tail

What is this view

Study These Flashcards

palmar surface of left forelimb

cross section view

What is this view

Study These Flashcards

longitudinal view

What is shown here?

Study These Flashcards

mild tear of SDFT

called a core lesion

What is shown here?

Study These Flashcards

a severe tear of the SDFT

this is because the core lesion is taking up more than 50% of the overall structure

What is shown here?

Study These Flashcards

initial (L) and 5-month follow up (R) of SDFT injury

tendon is filling itself in with healthy tissue and not scar tissue

scar tissue shows up more white

What is shown here?

initial (L) and 4 month follow-up suspensory ligament suspensory desmitis more black in the image because the tissue is pulled apart and full of liquid

What is nuclear scintigraphy?

AKA bone scan Uses radiopharmaceuticals (Technetium - 9mm) to localize areas of inflammation (increased blood flow or increased osteoblastic activity) Dynamic versus static (rads and U/S) Post IV injection - Soft-tissue phase 15-30 minutes - Bone phase 2-4 hours

What lameness uses is nuclear scintigraphy used for?

Muscle disorders, non-specific causes, upper limb/back injuries

What are the concerns of nuclear scintigraphy?

Excretion of radioactive substance

What does the computed tomography (CT) do?

Uses x-ray to create a 3-D image, better visualization of bone and soft tissue structures X-ray tube diameter limits structures visualized: Below mid-radius and tibia, mid-cervical neck Requires anesthesia

What lameness uses are CT scans used for?

Chronic lameness with no radiographic or ultrasound changes, neurologic

What are the concerns of CT?

radiation exposure, anesthesia

What is magnetic resonance imaging (MRI)?

Uses magnetic to assess protons in hydrogen nuclei, produces high contrast resolution Majority of units require anesthesia, increasing use of standing units (require sedation) Limited focus area

What is MRI used in lameness?

bone and soft tissue

What are the concerns of an MRI?

magnet attracts metal, anesthesia

What is shown here?