Diagnostic Ultrasound 1
Card Set Information
Diagnostic Ultrasound 1
Clinical Practice ll
Clinical Practice ll
What are the two different types of ultrasound?
What is diagnostic ultrasound?
short bursts of ultrasound
Does diagnostic ultrasound cause damage to tissue?
What is therapeutic ultrasound?
constant wave of sound?
What is the purpose of therapeutic ultrasound?
used to breakdown tissue
What is the nature of sound?
wave of mechanical pressure
What is ultrasound transmitted through?
a medium - air, metal, body
What is a frequency?
cycles per second
What is frequency measured in?
1 hertz (Hz) = 1 cycle per second
1 megahertz (MHz) = 1,000,000 cycles/second
What ranges of frequency are used in veterinary medicine? What are the common frequencies used?
range from 2.5 - 12 MHz
commonly used: 3.5 MHz, 5 MHz, 7.5 MHz
Can people hear the frequency of an ultrasound?
What frequency can people hear? Dogs?
people: 20 - 20,000 Hz
dogs: 70 - 100,000 Hz
What is velocity?
speed of transmission of the sound wave
What is the formula for velocity?
velocity = wavelength x frequency
the velocity of ultrasound in the patient's body is a _____.
As frequency increases, wavelength _____.
As frequency decreases, wavelength _____.
How do we get shorter sound waves?
use higher frequency transducer (7.5 MHz) or setting
Short sound waves give _____ image resolution
clear, detailed picture
Shorter sound waves give _____ patient penetration.
What are some examples of what we can use shorter sound waves on?
abdomen in cats and small dogs
tendons of horses
Longer sound waves give _____ patient penetration
Longer sound waves _____ image resolution.
more grainy, less detail
What would we use longer sound waves to exam?
abdominal ultrasound in medium and large size dogs
How is the image of an ultrasound formed?
by the pattern, intensity, and depth of the reflected sound waves (echos)
Echos or sound waves are _____ in proportion to tissue density.
Does ultrasound penetrate air?
What color is air on an ultrasound?
What does ultrasound not penetrate air?
because there is such a great change in density between air and tissue
Ultrasound cannot see past air _____, _____, and _____.
trapped in hair coat
pockets in the GI system (stomach, intestines)
in normal lungs
Can ultrasound tell anything about a structure behind or surrounded by air?
Is bone dense?
What color is bone on an ultrasound?
Can ultrasound tell us anything about a structure behind or surrounded by air?
Does ultrasound penetrate fluid well?
What color is fluid on an ultrasound?
An ultrasound image will appear _____ if fluid has particles in it?
What are the intermediate tissues in the body?
most body tissues
What color are intermediate tissues on an ultrasound?
What is echogenicity?
how much does the matter reflect echos
quality of the echo produced by ultrasound waves in different matter
What are the different echogenicity?
How many echos does anechoic produce?
What color is anechoic?
Where do we see anechoic?
How many echos does hypoechoic produce?
Where do we does hypoechoic?
water or fluid with particles, urine, blood
What color is hypoechoic?
dark gray to black
How many echos does isoechoic produce?
about the same number of echos
What color is isoechoic?
shades of gray on screen
What is isoechoic?
soft tissue densities
How many echos are hyperechoic?
What does hyperechoic look like?
What things are hyperechoic?
Can we use barium for an ultrasound? Why or why not?
no - it reflects
What kind of contrast material can we use for an ultrasound?
can inject bolus of saline with little air bubbles into the jugular vein to watch it go through the heart
Is ultrasound safe?
yes - no ionizing radiation and can be used repeatedly
Is ultrasound invasive?
Does ultrasound require sedation?
not painful, no strange positions, patient tolerates it well, decreases cost
Other than looking at structures, what can ultrasound be good for?
permits guided aspiration or biopsy of lesions in internal organs
place needle correctly
avoid vital structures (example - large blood vessels)
What are some disadvantages to using ultrasound?
takes time to learn to use and evaluate
ultrasound shows cross sections - need to learn to interpret
equipment is expensive
Are we able to distinguish between soft tissue densities and liquid densities using ultrasound? Xrays?
Is ultrasound hazardous? X-ray?
Can you examine the internal structures of organ using ultrasound? X-ray?
Are we able to examine structure in real time using ultrasound? X-ray?
Does ultrasound give us a large, over-all picture? X-ray?
Why do we need to prep the patient for an ultrasound?
to prevent the presence of air between the patient and transducer
How do we prep the patient for ultrasound?
clip closely to remove hair
apply contact gel
Why do we need to clip the hair before ultrasound?
hair holds air next to the skin and clipping the hair removes scales, dirt and debris
Why do we use contact gel for ultrasound?
for better skin contact
What is the transducer?
What does the transducer contain?
What are the piezoelectric crystals for?
when electricity is passed through the crystal, the crystal vibrates and produces ultrasound waves
What are the different types of transducers?
What is a linear array transducer?
several crystals placed side by side
What kind of image does a linear array transducer produce?
What does the linear array transducer look like?
"in line" or "T" shaped
Linear array has a large _____.
footprint or contact area
What is a linear array transducer good for?
transrectal reproductive exams in cattle and horses
What is a sector scanner?
the crystal sweeps back and forth across the area
What does a sector scanner image look like?
wedge shaped image
What does a sector scanner look like?
probe shape - rod or cone shaped
What size footprint does a sector scanner have?
What is the sector scanner commonly used for?
can put between ribs
commonly used in small animals
Why do we use different transducers or change the settings?
to get different frequencies of ultrasound waves
Different frequencies have different size _____.
What is the 3.5 MHz frequency used for?
big dog, horse abdomen
What is the the 5 MHz frequency used for?
medium to big dog abdomen
What is the 7.5 MHz frequency used for?
very good resolution
cat and small dog abdomens, eyes, tendons of horse
What does the transducer do?
transmits and receives sound waves
integrates picture and displays it on the screen
Transducer transmits about _____ of the time. Transducer receives about _____ of the time.
Returning sound is converterd to _____.
What are the different types of display modes?
What is the B-mode?
What does the B-mode produce?
most recognizable images
"real time" or "static" images
What are "real time" images?
sees structures as they are at that moment
What does "real time" allow us to do?
view and evaluate the motion of a structure
What is a "static" image?
can freeze a frame of a real time image
What is M-mode?
What scanner is used for M-mode?
What do the crystals in the sector scanner do?
crystals stays still, sees things moving past it
What kind of images does the M-mode produce?
rectangular image with squiggly lines
Is the M-mode used often in veterinary medicine?
What is the M-mode mainly used for?
What does the M-mode measure in echocardiography?
thickness of heart walls, valves, and great vessels
What are the different ultrasound artifacts?
What is acoustic shadowing?
area of darkness occurring deep to a dense structure
What is acoustic enhancement?
area of brightness occurring deep to a fluid-filled structure
How do we clean the ultrasound equipment?
wipe off probes and units as needed with water or mild disinfectants
Can we clean the ultrasound equipment with alcohol?
no because it will damage the surface
What are some clinical uses for ultrasound?
What kind of animals do we usually use ultrasound to evaluate tendons?
What happens to tendons when they are injured?
the parallel fibers pull apart and fill with blood
What do we need in order to look into the thorax?
Where do we look between or beneath to see structures in the thorax?
between or beneath the ribs
What can you detect in the thorax using ultrasound?
fluid in or around lungs
masses in lung if not surrounded by air
When can you use ultrasound to diagnose pregnancy in mares? Dogs?
: day 14
: day 18 - 20
What do we evaluate about the fetus during an ultrasound?
gas (cause - decomposition of dead tissue)
What do we evaluate about the heart during an ultrasound?
see valves move
measure thickness of walls
What do we evaluate about abdominal organs during an ultrasound?
masses in liver
calculi in bladder
What kind of mass evaluation do we do with ultrasound?
What do we evaluate about the eye during an ultrasound?
mass behind eye
Other than evaluating structures, what can we use ultrasound for?
guidance for fine needle aspiration (example - cysto)
guidance for biopsy
guidance for culture