Ultrasound (lecture) Flashcards
KNOW: Ultrasound is utlized in out pt settings for msk disorders
Heat is used for chronic swelling
(tendinosis = chronic inflammation)
(tendinitits = acute inflammation)
(tendinopathy = some tendon disease)
Is transmision of heat (or any wave) transmitted better through dense objects or non-dense objects?
Dense (conserves the integrity of the wave?)
think blue whale can be heard for miles)
What do we put on the pt before doing ultrasound? Why?
Gel
Helps the heat be transmitted better
Ares of increased molecular density (compressions or refractions?)
compressions
Areas of decreased molecular density (compressions or refractions?)
Refractions
Once waves reach a change in tissue density what 3 things could happen?
Reflection
Refraction
Absorption
Know: Reflected waves can increase or decrease treatment wave intensity
Well less dense tissue absorb ultrasound waves well?
No! we said earlier that water absorbs heat waves well = increase density
Give some examples of tissues that dont absorb ultrasound well. Why don’t they absorb it well?
Muscle, blood, fat, muscle
because none of it is very dense (solids absorb the best)
So bone, tendon, cartilage, all absorb really well
tendinopathies / platnar fasicits are good for ultrasound because they’re tnedon which is dense and superficial
What absorbs ultrasound better, muscle or bone?
Bone (denser)
KNOW: Ultrasound machine goes back and forth between convex and concave to create waves (the frequency of waves is how fast it flips back and forth)
What is the frequncy range of an ultrasound machine?
1 million - 3.3 million
or
1-3.3MHz
this is talking about the # of waves per sacond
KNOW Effective radiating area = area that wave energy will be transmitted form the head of the ultrasound machine
Will effective raiding area be bigger or smaller than the sound head of the ultrasound machine?
Smaller!
It will be smaller because if you just put the head of the machine down on the skin that area thats radiated (in that singular spot) will be smaller than the head itself
What freqency is best for deeper tissue?
1 MHz (smaller frequency reaches deeper tissue better)
3.3 MGh frequency is for what kind of tissue?
Superficial tissue (think base in car = lower amount reaches deeper)
what frequency propages further - lower or higher
Lower
What creates faster warming - increased or decreased frequency?
Increased frequency (think 3.3 MGh)
What is intensity?
Wave amplitude (how high the waves are)
More energy w/ increased intensity
As intensity increases what happens to tissue warming?
It also icnreases
What should intensity be set on?
1.5
KNOW: increased frequency (3.3 MgH) and intensity = super fast warming of tissue
If my goal is to warm deep tissue waht frequency do I use?
1
Part of the reason we use 1MgH for deep tissue is so we don’t heat up all that superficial tissue it must go through first. This allows the waves to go through superficial tissue first without heating it too much and reach that deeper tissue and begin the warming process (think cooking chicken on low heat)
What is dosage?
* what 3 things increase dosage
amount of energy were sending into pt in treatment time
So if treatment time is increased so is dosage
Increased intensity = increase dosage
Increased frequency = increased dosage
How long is treatment for ultrasound?
5-10 minutes (same as ice massage)
How often should ultra sound typically be done?
2-3x/week for 1 month
What is continuous ultrasound?
constand energy throughout treatment
more energy = more thermal effects
If we want to warm the tissue would we use theraml or pulsed ultrasound?
continuous (more thermal effects)
What is pulsed ultrasound
Period of time without delivered energy
Less energy = less thermal effects
(not much evidence to support this)
What should we set duty cycle to on an ultrasound
100 or 1 we want the ultrasound machine to be continuous (this is the amount of on time / amount of treatment time * 100)
how big is the treatment area when compused to the ultrasound machine head?
2-4 times as big as head
Why do we want the area being treated by the ultrasound machine to be no bigger than 4 times as big as the head?
poor thermal effects when we spread it out that much
KNOW: For ultrasound do small circles that end fit together in a big circle
KNOW: We never want to stop moving w/ ultrasound (we don’t want any hotspots)
Why must we move the soundhead when doing treatment
to prevent hotspots
KNOW: How to do ultrasound:
Confirm appropriate patient and treatment area
Position patient in comfortable and accessible position
Turn on units and set appropriate parameters (frequency / duration / intensity / duty cycle [continuous = 100% and pulsed = 50%])
Place gel on skin
Make contact w/ skin, move sound head BEFORE hitting start (prevents hotspot)
What heats faster muscle tissue or tendin?
Tendin heats 2x faster
How long do the effects of ultrasound last?
No more than 5 minutes
Which would have an increased treatment time, muscle or tendin? Why
Muscle because its less dense and will absorb less heat - so you will need to heat it longer to get thermal effects
KNOW: Ultrasound wouldnt be good for a fat person because all that adipose tissue would need to be heated before muscle tissue
Is exercise heating the body via convexion or conduction?
Convexion
What are the contraindications of ultrasound?
Pregnancy (dont use it over the abdomin)
Active bone growth at epiphysis (dont use on growth plates of kids)
Cancer (don’t want to warm cancer tissue = more BF = grow cancer)
Tuberculosis infection
Hemorrhagic conditions (active bleeding / hemophilia) - think a brusied area
Impaired circulation (don’t want to send more blood to bad vessels)
Consideredations for ultrasound (dont do it)
Myositis ossifications (bone growth in m tissue) - warms the bone fast (think thermal injury do to burn of bone)
DVT (dont increase BF in an area where theres a blood clot)
Acute injury - dont want heat in a swollen area (theres already lots of blood here)
Areas recently exposed to radiation - they’ve already been exposed to lots of energy and we don’t want to expose them to more
impaired sensation
impaired cognitiion/communication
Skin disease
Pacemaker or other implanted electronics
reproductive organs
Eyes
Anterior neck
Should you ultrasound over an implant?
No
think birth control one in arm / blood sugar monitor
Where spicfically should you look for implants?
Upper arm
Should you document all the setting and that you used a coupling agent (gel)? (and pt position)
Yes
When is ultrasound typically used
For pain (think pts just having back pain)
KNOW: ultrasound can be used on inflammation (even though its a heat modality), i think its that its being used on chronicly inflammed tissue
What four inflamatory diseases would we used ultrasound for?
Carap tunnel
Calcific tendinitis
Bursitits
Arthritis (pain)
KNOW: Ultrasound is good for pts that are afraid of moving (because this is the best way to warm up tissue) - hwoever - ultrasound sucks
KNOW: pts w/ carpal tunnel, calcific tenditits, bursitits, arthritits, back pain, myosfascial pain,
Watts/cm^2 is what?
Intensity
KNOW: Explain effects of ultrasound to pt (its thermal and only lasts 5 minutes)
