Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Diagnostic imaging > 2- ultrasound > Flashcards

2- ultrasound Flashcards

1
Q

how does the ultrasound work

A

high frequency sound waves penetrate tissue (or don’t) and bounce back to transducer
- crystals in transducer converts sound waves to electric current and converted to image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the acoustic impedance of fluid, soft tissue, fibrous tissue and solids

A

fluid (blood): black
- waves go straight through

soft tissue (liver): grey
- a lot goes through but some bounce back

fibrous tissue (diaphragm): white
- a lot bounces back

solid (stone): ?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what does ultrasound hate

A

Air (all the waves bounce back)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does anechoic mean

A

black color

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what does hypoechoic mean

A

dark grey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does hyperechoic mean

A

white - bright

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does isoechoic mean

A

light grey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does reflective mean

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

explain the acoustic shadow

A

artifact - you cannot see below a structure that reflects back all waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is acoustic enhancement

A

artifact - brightness deep to anechoic structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a reverberation artifact

A

sound waves reflection multiple times between 2 strong reflectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is a mirror image artifact

A

duplication of image of the opposite side of a strong reflector
- most common from thorax/abdomen interface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is a slice thickness artifact

A

from imaging a 3D structure with anechoic fluid
- most common in the bladder and gall bladder = artificial sludge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is a edge shadow artifact

A

when sound waves bend as they hit a curved surface tangentially

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the different types of ultrasound transducers

A

linear
- large foot print and most commonly used for equine tendons

curvilinear
- either used for SA or LA abdomen and thorax
- small foot print

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does an increased frequency (mHz) mean

A

greater resolution but less depth

17
Q

what does a decreased frequency (mHz) mean

A

greater depth but less resolution

18
Q

what can real-time imaging (doppler mode) measure

A

movement
- heart movement = heart beat

can assess direction of flow
- regurgitation of blood though a leaky valve

19
Q

what are the principles of computed tomography (CT scan)

A

X-ray tube in a circle
- intensity of x-ray allows for differentiation of structures
- computer reconstructs the data to make a “slice” image

  • 2D slices to allow 3D location (way more detail and gets around superimposition of radiographs)
20
Q

how are CTs applied to vet med

A

animals are anesthetized or very heavily sedated

  • imaging in horses “generally” limited to carpus/tarsus, digit and the head
    —– there are also standing CT machines for LA that can do more
20
Q

what are the common imaging done with CTs

A

detailed evaluation of bone
- fracture repair planning
image the head
image spine
image the abdomen
- requires inj of contrast to enhance lesions (limited)

21
Q

what are the principles of magnetic resonance imaging (MRI)

A
  • all tissues have lots of hydrogen protons because they are made of H2O
  • STRONG magnet is applied and protons are excited by a radiofrequency pulse

pulse removed -> protons relax -> emits signal
- protons in different tissues relax differently

22
Q

what precautions must be taken with MRI machines

A

must remove anything metal and use non magnetic anesthesia equipment

23
Q

MRI vs CT

A

both allow for tomography and 3D reconstruction

MRI has better contrast resolution
- superior for imaging soft tissues

CT is superior for imaging bone because it does not have a much water
– for fracture planning!!

24
Q

what is the pro of using and MRI in equines

A

imaging soft tissues and bone lesions in areas where ultrasound is not possible = the foot

25
Q

what is MRI used for commonly in small animal

A
  • neuroimaging
  • musculoskeletal
  • tumor staging
  • possible abdomen and cardiac
26
Q

what are the principles of nuclear scintigraphy principles

A

Inject a drug that is bound to a rapidly decaying radioactive atom
- gamma camera detects decay of radioactive atom

increased done formation –> increased uptake –> increased atoms decaying –> increased signal

27
Q

how are nuclear scintigraphy used in equine pts

A
  • localize lameness (after failed block or no lesion on rads/ultrasound)
  • multiple limb lameness
  • upper limb or axial musculoskeletal issues
  • suspect fracture not seen on X-ray
  • mild, intermittent lameness that precludes blocking
28
Q

how is nuclear scintigraphy used in SA

A

renal function
thyroid
musculoskeletal

29
Q

add photo of chart

A

Diagnostic imaging (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions