Ultrasound

Question 1

Ultrasound Basics

Answer 1

• Deep heating modality
• Inaudible sound waves of high freq that produces both thermal and nonthermal physiologic effects

Question 2

Ultrasound Indications

Answer 2

• Non-thermal — acute condition and bone healing
• Thermal — scar tissue and joint contracture
• Inflammation
• Muscle tightness
• Pain
• Increased blood flow

Question 3

Ultrasound Angle & Gel Medium

Answer 3

• Gel applied generously across treatment area
• Angle — perpendicular

Question 4

Ultrasound Procedure

Answer 4

• Constantly moving
• Clockwise or counterclockwise

Question 5

Effective Radiating Area (ERA)

Answer 5

• Treatment area should be at least 2x the size, but no greater than 4x the size of the effective radiating area (sound head)

Question 6

Beam non-uniformity ratio

Answer 6

• Ratio of spatial peak intensity divided by spatial average intensity
• Poor units 6:1 or greater create “hot spots”
• Should be 5:1 or less

Question 7

Ultrasound Frequency & Duration

Answer 7

• No real consensus
• 10-15 minutes is recommended on NPTE(8 minutes is typical)
• 2-3x/week

Question 8

Ultrasound Depth

Answer 8

• 1mHz — deep (3-5cm, bursitis, arthritis, epicondylitis, myofascial pain, back pain, CTS, calcific tendinitis)
• 3mHz — superficial (1-2cm, joints, superficial tendinitis, CTS, calcific tendinitis)

Question 9

Ultrasound Intensity/Power

Answer 9

• Acute = 0.5-1.0 Wcm^2
• Subacute = 1.0-1.5 Wcm^2
• Chronic = 1.5-2.0 Wcm^2

Question 10

Ultrasound Duty Cycle (on/off time)

Answer 10

• 20% — pulsed, non-thermal, acute conditions
• 50% — pulsed, non-thermal, subacute conditions
• 100% — continuous, thermal, chronic conditions

Question 11

Ultrasound Contraindications

Answer 11

• Acute and post op conditions (cannot use thermal but can use non-thermal)
• Pregnancy (cannot do abdomen or lower back)
• Areas of decreased sensation
• Pacemaker
• Epiphyseal plates (active bone growth)
• Precaution — total joint replacements

Question 12

Ultrasound Water Immersion Technique

Answer 12

• Putting limb into water instead of putting it directly to skin
• Since it is not directly on skin and just around the skin, we want to increase the intensity
• Therefore, we would increase the intensity by 50%
• This is used when providing US to irregular surfaces
• US head should be held 1cm away from the treatment area

Question 13

When patient complains of burning when using ultrasound…

Answer 13

• Malfunctioning unit
• Too high BNR —> 6:1 or more
• Intensity or duty cycle set too high
• Improper depth