Ultrasound Therapy, Imaging and Shockwaves

"Hi MCR, I keep hearing about ultrasound therapy but I get confused with the seemingly different answers I get about them. There appears to be one for healing bruises and swells. And another to 'see' inside and another to blast off pieces of our bones at the heel of our foot. Are they all the same thing?" – Swee Yong

Dear Swee Yong,

Thanks for your question. Yes, indeed it can be confusing because medical professionals tend to just to refer to it as 'ultrasound', leaving their specific context to mean which type of ultrasound.

Therapeutic Ultrasound

The first one you mentioned about healing swelling is what is called 'Therapeutic Ultrasound'. Used in physiotherapy, this is a high frequency (0.7 to 3.3Mhz) but low energy sound wave. Absoprtion of these sounds waves by the tissues causes the cells to vibrate. The vibrational energy stimulates the cell-repair effects which helps to expedite the healing process. Also, when the sound waves are absorbed into the tissues, they are converted to heat energy which helps to improve circulation.

Compared to other types of 'heat' treatments such as a hot pack, ultrasound is able to penetrate deep into the affected area. When we say 'ultrasound' in the physiotherapy context, we actually mean this form of ultrasound.

Usually at Core Concepts, we use 'therapeutic ultrasound' as an adjunct to our main treatment option as healing the tissue is not enough. We first need to fix the reason behind the tissue injury.

Ultrasound Imaging

The second type of ultrasound you mentioned to 'see' inside, is 'Ultrasound Imaging'. This the type of ultrasound device used by your OBGY to see the baby inside. Much like the 'sonar' of a submarine, sound is used to look inside. The higher the frequency of the sound, the image is sharper but does not penetrate as deeply. (7-18Mhz) for structures nearer the skins such as muscle and 1-6Mhz for deeper body parts such as livers and kidneys. Gyneas and OBGY means this when they say, 'ultrasound'.

At Core Concepts, we use a similar version of Real-Time Ultrasound Imaging to help our clients visually and confirm deeep muscle contraction, particularly for their core muscles.

Shock-wave Therapy

The last type of ultrasound you mentioned is commonly referred to as Extracorporeal Shockwave Therapy (ESWT). Compared to the continuous lower-energy waves of'therapeutic ultrasound, ESWT machines send higher-energy pulses 2 or 3 times per second. These high-energy shockwaves blast off hard structures like heel spurs or kidney stones. The high-pressure waves also help promote healing. ESWT is never referred to as ultrasound though all three types use sound waves.

Hope this helps clear up some of the confusion.