WK3-US Flashcards
US creates heat in tissues most likely as a result of
molecular vibration
Added heat buildup at the periosteal junction of bone can occur most likely as a result of
acoustic wave reflection producing standing waves
The best estimate of effective radiating area (ERA) of the ultrasound applicator is
Area of the piezoelectric crystal
The relationship between US frequency and depth of penetration is
Lower frequency US penetrates deeper than higher frequency US.
Which would be the most appropriate ultrasound (US) parameters to treat a joint contracture of the posterior hip (used prior to stretching the joint capsule)?
1 MHz continuous US
Which of the following best describes the appropriate use of therapeutic modalities for rehabilitation programs?
Adjunctive components of a comprehensive therapy program
Ultrasound most effectively heats __________ tissue with __________collagen content such as tendons, ligaments, joint capsules, and fascia.
deep, high
Ultrasound is generally classified according to its thermal and nonthermal effects. Which ultrasound setting is most responsible for whether there will be thermal or nonthermal effects?
duty cycle
A common mistake made by therapists in heating a tissue using ultrasound is
Applying US over too large of an area
What factors affect the amount of temperature increase when using thermal US
the type of tissue where the ultrasound is applied (i.e. tissue with higher collagen content heats more rapidly)
the intensity setting
the duration of the treatment
the frequency setting
The technique used to reduce the risk of burning while still getting an effective treatment with an ultrasound applicator with a high beam nonuniformity ratio (BNR) is to
Move the US applicator while applying the US.
Which ultrasound setting is responsible for the depth of ultrasound penetration?
frequency
The optimal treatment area to get the most rapid heating of the tissue is
2x ERA
The optimal intensity to achieve a heating effect of US in muscle tissue is
There is no optimal intensity because the intensity must be adjusted to meet the needs of the specific patient and the characteristics of the specific US device.
When applying ultrasound to heat tissues, which of the following is used to determine the final ultrasound intensity?
the patient’s report of warmth
Using thermal ultrasound in tissues with higher collagen content with a frequency of 3 MHz (as compared to 1 MHz), the depth of ultrasound penetration is more ________, but a _________ maximum temperature is achieved.
superficial, higher
Pulsed ultrasound, with a duty cycle of ____ is most commonly used to produce the nonthermal benefits of ultrasound
20%
Clinical indications for using therapeutic ultrasound include the following
phonophoresis
soft tissue shortening
carpal tunnel syndrome
tendon and ligament injuries
soft tissue healing
pain control
bone fractures
The ________ effects of ultrasound are used primarily before stretching of shortened soft tissue and to reduce pain. Whereas the __________- effects of ultrasound are used primarily for altering membrane permeability to accelerate tissue healing.
thermal, nonthermal
There are variations between the heating rates of different tissues. What is the relationship between the heating of tendons or ligaments and skeletal muscle under similar sonication conditions?
The heating rate and temperature rise seen in tendons/ligaments is between 2.5 and 3 times the rate seen in skeletal muscle.
The optimal coupling medium used to apply ultrasound is
US gel
When determining the duration of the ultrasound treatment, for most thermal and nonthermal application, ultrasound should be applied for _________for each treatment area that is ___________
the ____________ of the transducer.
5-10 minutes
2x
effective radiating area (ERA)
Ultrasound duty cycle is selected according to the treatment goal. When the goal is to increase tissue temperature, a _________ duty cycle should be used. When ultrasound is applied where only nonthermal effects without tissue heating are desired __________ ultrasound with a _________ duty cycle should be used.
100% (continuous)
pulsed
20%
There is strong substantiated evidence for the use of continuous US to treat
pain and dysfunction of Carpal tunnel syndrome
(T/F) The effective radiating area (ERA) is defined as the area of the transducer from which ultrasound energy radiates. Because the crystal does not vibrate at its margins the ERA is always smaller than that area of the treatment head
True
There is strong substantiated evidence for the use of pulsed US to treat
There is no compelling evidence for any use of pulsed US
In general, ultrasound seems to be most effective in treating
painful conditions
Evidence is moderate to strong for the contraindication of the use of continuous US in all of the following areas and conditions EXCEPT
Cancer—over a known or suspected area of malignancy
Hemorrhagic conditions—over an area of active bleeding
Active bone growth at the epiphysis
Pregnancy—over the shoulders, upper back, and cervical regions
Pregnancy—over the shoulders, upper back, and cervical regions
(T/F) phonophoresis evidence is strong and substantiated in the application of hydrocortisone
False
What is LIPUS
a kind of US that is standardized and low intensity to improve bone healing in the case of fractures.
What is NCLFUS
a kind of non contact US that improves wound healing by atraumatic selective tissue debridement, wound stimulatory effects, and antibacterial activity.