Ultrasonography

Question 1

Probe types

Answer 1

Array - linear or curved - wide superficial view (MSK, abdomen, eyes, thorax)
Phased linear array - flat - direct field of view (deeper structure, echo)

Question 2

Controls (5)

Answer 2

gain - blackness
time gain compensation - adjusts gain at different depths
depth - zoom in and out
frequency - image resolution at level of object being assessed (higher = near, lower = deeper, higher has decreased penetration and increased resolution)
focus zones and position - narrows pulse at specific depth

Question 3

echogenicity

Answer 3

hyperechoic - strong echoes - bone, fat, stones, air
hypoechoic - weak - soft tissue, muscle
anechoic - no echoes - fluid

homogenous - uniform
heterogenous - non-uniform

Question 4

Artefacts

Answer 4

reverberation echo - bounces between 2 interfaces
shadowing - reflection of beam, black deep to block
mirror image - organs reflect distally instead of back to probe - makes multiples of a structure appear

Question 5

B-mode

Answer 5

normal ultrasound image in echo

Question 6

M-mode

Answer 6

sound wave mapped against time

e-wave - passive filling of left ventricle
a-wave - active filling (atrial contraction)

Question 7

fractional shortening

Answer 7

scaling to account for different sizes of animal in heart measurements

cat - 30-50%
dog - 25-50% (large breed down to 20%)

Question 8

cornell measurement

Answer 8

scale to body weight where breed reference ranges don’t exist

enlarged at <1.7

Question 9

aortic ratio

Answer 9

left atrium : aortic valve ratio - measured when atrium biggest

normal <1.5

Question 10

Echo - views

Answer 10

Right parasternal long axis - D shape left ventricle

Right parasternal short axis - mushroom

Aortic valve - mercedes sign

Question 11

Indications for echo

Answer 11

heart murmur
breathlessness, cough or collapse
arrhythmia
pericardial disease
pericardial effusion
unexplained pyrexia
breed screening
pre-chemo assessment

Question 12

stenosis

Answer 12

narrowing