Ultrasound

Question 1

4 Physiologic Responses to US

Answer 1

1. Non-thermal

Question 2

Parameters

Answer 2

Frequency: 3MHz for 1-2cm superficial tissue
1 MHz for 2-5cm deep tissue
-high freq=more oscillation=more energy in superficial=less for deep

Sound Waves: continuous=stays same
Pulsed= intermitant
Duty cycle= duration on/total time
20 and 50% most common (non-thermal)

Intensity= rate energy/unit area [W/cm2]
higher intensity=higher thermal effect
0.5-2.0 W/cm2

SATA= spacial average temperature avg
For non-thermal: 0.1-2.0 W/cm2-> pulse 5-10 min

ERA= effective radiating area
x2 is treatment size

Sound head movement 4cm/s

Question 3

6 Thermal Physio Responses to US

Answer 3

1. Increase collagen tissue extens
2. Increase blood flow
3. Increase pain threshold
4. Increase nerve conduction velocity
5. Increase metabolic activity
6. Decrease muscle spasm

[therapeutic window 4 min after-> intervention immediately or during]

Question 4

2 Physio Processes of Non-Thermal US

Answer 4

GOAL: enhance healing process in acute phase

1. Cavitation: stable gas buble in tissue expands/compresses causing vibration
2. Acoustic Microstreaming: pressure diff from cavitation causes circular flow of fluids
   - Microscopic currents increase membrane/vascular wall permeability
   - Movement of ions into/out of membrane

Question 5

4 Results of Non-Thermal Physio Processes

Answer 5

1. altered cell membrane permeability (Na/Ca)
2. stimulation of fibroblasts
3. increase protein synthesis
4. increase tissue regeneration

Question 6

US Indications

Answer 6

acute/subacute probs
soft tissue heal/repair
tissue regen, protein synth
increase blood flow
increase extensibility/scar tissue mobil
joint contracture
reduce chronic inflam
reduce muscle spasm
pain mod
myofascial trigger points

Question 7

US Contraindications

Answer 7

Acute/active inflam process for THERMAL
Decrease sens/circ
vascular insuffic
infections
eyes, reprod organs
pregnancy
malignancy
epiphyseal in kids