quiz #1 – ultrasound

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what is ultrasound
- high-frequency sound waves >20,000 Hz
- therapeutic ultrasound 1–3 million hertz
how deep does ultrasound penetrate

approximately 5 cm
how does ultrasound produce heat

through friction
true or false – absorption decreases with density of tissue

false – absorption increases with density of tissue
what is cavitation
the creation of bubbles
- bad for blood
- cerebral spinal fluid– don't cross the spinal cord, okay to go parallel with the spinal cord
- eyes- don't go over forehead
what does this picture represent

refraction
What is refraction?

a change in direction of the soundwave due to different density of tissues
what does this picture represent

reflection
What occurs with reflection?

the wave doesn't penetrate but instead bounces off
true or false – the periosteum of the bone is at risk for burns when performing ultrasound

true- this would occur due to reflection
what is piezoelectric effect

AC passes into crystal which vibrates at same frequency as AC
what is transduction

change of one energy to another

Vibration to electricity and electricity to vibration
how is the intensity of ultrasound measured and what is a typical value used in the clinic?
- Watts/cm squared or Watts
- .5-2.5 watts/cm squared
true or false – crystals in ultrasound heads are now synthetically made

true
the typical outlet has a frequency of _____ Hz
And power of _______V
- 60 Hertz
- 120 V
Inductor
Resistor
capacitor
which frequency will penetrate the body at a greater depth?
A) 1 MHz
B) 3 MHz

A) 1 MHz
how long does the typical ultrasound treatment last

5– 10 min.
what are some examples of coupling medias
- ultrasound gel
- water
true or false – ultrasound treatments always cover a large area

false – areas treated are always small
what are some of the therapeutic effects of ultrasound
- relieve pain– thermal effect
- increase elasticity of tissue – thermal effect
- reduce inflammation – thermal effect
- break adhesions/mineral deposits – mechanical effect
- push drugs through the skin – mechanical effect (steroid products)
what are the indications for ultrasound
- subacute/chronic inflammation
- joint contractures
- muscle spasms
- scar tissue (be careful with thermal modality on a scar)
- trigger points
- calcium deposits
- plantar warts
- chronic ulcers
what are some of the contraindications for ultrasound
- acute inflammation
- hemorrhage
- vital organs – heart, neck, etc.
- epiphyseal growth plates
- fractures (will break up the new callus)
- malignant tumor (break off cancerous cells)
- pregnant abdomen
- infection
- thrombophlebitis (causes swelling and pain)
- impaired sensation
- impaired circulation
- metal implants

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BPT

64111

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quiz #1 – ultrasound

Description

ultrasound

Updated

2011-02-27T01:57:41Z

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