Ultrasound Flashcards
What tissues does ultrasound effect the most?
Tendons
Ligaments
Joint capsules
Fascia
What’s the difference between pulsed and continuous ultrasound?
Continuous-Used for thermal effects
Pulsed-produces nonthermal effects
What are the units of measurement for US?
Intensity - W/cm2
Frequency - MHz
Duty cycle - % or ratio
Effective radiating area (ERA) - cm2
What are some effects of Thermal US?
Affective for heating smaller areas Can increase the tissue temperature by : -Tissue type -Intensity -Frequency
What depth do the different US frequencies go to?
1 MHz - Up to 5 cm deep
3 MHz: 1 - 2 cm deep
What are some effects of nonthermal US?
Cavitation, microstreaming, acoustic streaming
Increased intracellular calcium
Promotes cell function
What are some clinical applications for US?
Soft tissue shortening Pain control Dermal ulcers Surgical skin incisions Tendon and ligament injuries Bone fractures Carpal tunnel syndrome Phonophoresis
What are US contraindications?
Malignancy Pregnancy CNS tissue Joint cement Plastic Pacemaker Thrombophlebitis Eyes and reproductive organs
What are some precautions for US?
Acute inflammation
Epiphyseal plates
Fractures
Breast implants
What are some adverse effects of US?
Burns (Worse in areas of poor circulation, keep head moving)
Standing waves (cause blood cell stasis)
Cross-contaminations and infection (clean transducer before and after each use)
What are the parameters for US?
Frequency -1MHz = 5 cm deep -3MHz = 1-2 cm deep Duty Cycle -100% = thermal -20% = nonthermal Intensity (thermal) -1MHz = 1.5-2W/cm2 -3MHz = .5 W/cm2 Intensity (nonthermal) -0.5-1W/cm2 Duration -5-10 min
What all do you need to document with US?
Area treated US frequency US intensity US duty cycle Treatment duration If underwater Response to intervention
What is Diathermy?
Means through heating
Uses shortwave or microwaves to produce gentle heat in large areas
How do you determine the temperature with diathermy?
Field intensity
Tissue type
Duty cycle
Distance from patient
What are some types of diathermy?
Inductive Coils - shortwave
Capacitive plates - shortwave
Magnetron - Microwave
What are some traits of the inductive coils?
Uses magnetic field and can heat superficial and deep structures
(greatest in superficial structures)
How do Capacitive plates work?
High frequency alternating electrical current flows from one plate to the other through patient. (poor heating for deeper structures)
When is the magnetron type of diathermy most useful?
Best when there’s only a small area of tissue. (most heat is superficial)
What are the diathermy clinical indications?
Thermal -Pain control -Accelerated tissue healing -Decreased joint stiffness -Increased joint ROM Nonthermal -Control pain and edema -Soft tissue, nerve, and bone healing -Improvement of OA symptoms
What are some contraindications for diathermy?
All Diathermy -implanted or transcutaneous stimulators, (pacemakers) -Pregnancy Thermal -Metal -Malignancy -Eyes -Testes -Growing epiphysis Nonthermal -Deep tissues/internal organs Substitute for conventional therapy for edema and pain -Pacemakers, electronic devices, or metal implants
What are some precautions for diathermy?
All -Near electronic or magnetic equipment -obesity -copper bearing IUD Nonthermal -Pregnancy -Skeletal immaturity
How far away does the PT need to stance from the applicator?
1-2m and out of direct beam
What are some adverse effects of Diathermy?
Burns
- particularly fat layers
- keep skin dry
What all do you want to document with diathermy?
Area treated Frequency range Average power or Power setting Pulse rate Treatment duration Type of applicator Patient position and distance from applicator Response to intervention
