ultrasound Flashcards
T/F US must be absorbed by tissue for effect
t
T/f ultrasound is preferential absorbed by tissues with lower protein content
false - HIGHER
is ultrasound better absorbed by blood or bone
bone cus higher protein content
is 1 or 3 Mhz better for deep
1
is 1 or 3 MHz better for superficial
3
biophysical effects of ultrasound
thermal
non-thermal
the resting ____ causes heating from US
molecular friction
temperature increase from thermal US depends on
amount of energy applied
frequency of sound wave
type of tissue
duration
T/F 3 Mhz heats faster than 1
yes but more shallow
vigorous heating at ___ fora atlas 5 minute may increase extensibitly of joints, legs, scar and cause vasodilation
40-45C
T/F vigorous heating will provoke inflammatory reaction helpful in tissue healing
T
temps > 45 are destructive
true
effects of mild heating
reduce pain, mm spasm promote healing alter nerve conduction velocity vasodilation increase activity
T/F US is a good way to heat near bone or joint
yea if the area is small
what risk of US tho
overheating cus periosteum can’t dissipate heat quickly so keeper moving
Thermal US for
pain relief
decrease joint stiffness
improve blood flow
promote tissue healing
non thermal ultrasound. mechanisms
cavitation (stable and unstable)
acoustic streaming
standing wave
micromassage
cavitation
tiny bubbles. stable or unstable.
stable might be good but unstable are mad
stable cavitation
bubbles form then oscillate, they might help in acoustic streaming
unstable cavitation
bubbles do large increase and decrease in volume and implode
could cause damage
acoustic streaming
unidirectional flow around stable bubbles alters NA permeabiltiy influx of Ca accelerate tissue repair
problem with cavitation studies
in vitro
standing waves
tissues isn’t homo so its unlikely these dangerous waves happen plus you’re moving the head
high intensity energy
micromassage
caused by waves of compression
causes pressure differences
thought to reduce edema
non thermal effects of US
increased membrane permeability
stimulation of protein synthesis
improve scar tissue
how does US optimize inflammation
releases wound healing factors
t/f US augments tensile strength
t
joule calcuation (total energy)
w/cm2 x cm2 x SECONDS
phase of healing impacts US type
inflam - low dose
prolif - higher
remodelling - higher
whats most important factor in US
total energy given
energy determinants
intensity continuous or pulsed frequency size of area duration treatments
when do you use low dose
acute inflammatory phase
when do you use high dose
chronic , after first stage of healing
shorter duration for acute or chronic
acute
total energy depends on
intensity and duration
frequency of US
acute conditions daily
chronic alternate days at higher dose
how to record US
Watts, pulsed, hertz, time, where
indications for US
pain
contraindications for ultrasound
ab if preg lamigancy heemoraphage haemophilia active DVT eyes anyeror neck
can you US metals
ok if using pulses b ut not over pacemaker or other implants
precautions US
SC or superficial nervs
regenerating vernces
epiphyseal plate is unfused
dosage depends on
nature of problem (acute, sub or chronic)
tissue
depth
size
LIPUS
low intensity pulsed US
might help with fractures, teeth and cartilage
does LIPUS help in fracture healing
yes but its not he equipment used in clinic
intensity for acute
.1-.3
intensity fo sub acute
.2-.5
intensity for chronic
.3-1
treatment time
1 x # of heads x pulse factors
how to determine pulse factors
add the ratio together
