The applications of Ultrasound in medicine

Ultrasound is widely used in medicine. The waves are generated by soliciting quartz with an electric field whose polarity is periodically reversed: due to the electromagnetic field that is created. The quartz compresses and expands, generating mechanical vibrations that cause the acoustic waves of ultrasound.

The waves lose energy, transferring it to the system they pass through with an attenuation mechanism when they penetrate into a biological system. The higher the wave frequency, the greater the attenuation (therefore, it penetrates less deeply). Generally, the waves enter up to depths between 1.5 and 5 cm. The biological system can be a tendon, a muscle, or a bone. The release of energy is converted into heat, whose therapeutic properties have been well known for hundreds of years.

The use of ultrasound for therapeutic purposes in orthopedics has been exploited since the mid-twentieth century. The heat-induced in the tissues is linked to the viscosity of the tissue (therefore its biological nature), its chemistry (composition), and thermal properties (conductivity). But heat transfer isn't the only effect. In fact, there is mechanical stress which produces a movement of the tissue molecules, inducing pressure variations. They allow the liquid to move inside the biological tissues and therefore have an effect in the presence of spills or to realign the collagen fibers.

The further effect of the acoustic waves that pass through a biological system is chemical, the pH and permeability of cell membranes are modified, facilitating the exchange and migration of liquids.

What is ultrasound?

The ultrasound is a diagnostic technique that uses ultrasound to provide an image of the scanned tissue. It is a non-invasive test that is neither painful nor annoying and absolutely free of risks and contraindications.

When the doctor performs the ultrasound, he spreads a conductive gel on the skin in correspondence with the organs to be explored and passes it over a probe that emits and records the ultrasounds. The ultrasounds - emitted by an electric generator and transmitted by the probe - impact against the different body tissues (muscles, organs, bones) and are reflected according to their different density. Thus ' echoes' are generated, which, through a graphic reworking, form the image of the explored tissues.

How are ultrasounds used in medicine? 

We know them as a diagnostic technique; for example, we think about ultrasound. But not everyone knows what ultrasounds are exactly, why they are so useful, and, above all, whether or not there are potentially harmful consequences for human health.

Ultrasounds: echography

One of the best-known uses of ultrasound is the use of ultrasound investigations. Ultrasound is precisely a diagnostic technique that is based on the "echoes" generated by ultrasound that cross a biological field (an organ or tissue). The ultrasound technique is used in radiology, obstetrics, and surgery.

This diagnostic technique allows, in fact, investigating what is called "soft tissues." For example, following a limb problem, the doctor may request both an X-ray (which does not allow you to see the soft parts) and an ultrasound, which can also highlight a "photograph" of the tissue.

The ultrasound is harmless and is also relatively inexpensive. However, it should be noted that the ultrasound depends very much on the professionalism and ability of the ultrasound operator. Simply we could say that the radiography is objective, while a good result of the ultrasound is very closely linked to the manual skills and, above all, to the correct interpretation of those who perform it.

Ultrasound as a therapy

Ultrasound is also used as real therapy, especially in the orthopedic field, and with ultrasound therapy, excellent results also obtained in aesthetic medicine.

The ultrasound therapy, therefore, is a therapeutic technique that uses precisely the action of sound waves (ultrasound) on a biological field (body). The power of the wave is in its ability to penetrate deep into the tissues. The waves used in ultrasound therapy have a frequency between 750 kHz and 3 MHz, the higher the frequency, the less deeply the wave penetrates. Therefore, the choice of the type of frequency changes according to the organ and tissue treated, and according to the type of therapy required. 

But why is the wave, or ultrasound, so beneficial? Because once it has entered the biological field, it performs various actions, a chemical action, a thermal action, and also an important action on the circulation. That's why ultrasound therapy is used for the treatment of arthrosis, arthritis, muscle contractures, sprains, tendinitis, sprains, muscle tears, bursitis, and even cellulite.

Ultrasound in physiotherapy

Therefore, ultrasound therapy is a great technique that is in physiotherapy. The ultrasound radiation, in fact, generates an effect similar to a micro-massage (mechanical button) and also a thermal effect, heating in depth.

This mix of actions ensures that cellular and intracellular exchanges are facilitated. Ultrasound treatment can be carried out in two different ways, directly and indirectly. The most used method is that for direct contact, which is a conductive gel is applied to the head of the appliance and on the area to be treated. Then, the head is moved with slow rotatory movement. The treatment in indirect contact, however, is performed in water.

The area to be treated is immersed in a kind of basin, and the head remains detached from the skin for about 1 cm. It is a less common but very useful method in the case in which irregular and difficult to treat areas must be treated directly, for example, elbows, hands, and malleoli.

The benefits of ultrasound, therefore, can be found at different levels. The therapy is analgesic (to combat pain), anti-swelling, anti-adhesion of the tissues, biostimulant at the cellular level, and a muscle relaxant (decontracting on the muscles).

Contraindications

Ultrasound is quite safe, but there are still contraindications. For example, sound waves cannot be used in areas adjacent to the heart if you suffer from cardiomyopathy. Similarly, its use near the sexual organs and bone marrow are contraindicated in the presence of neoplasms and thrombophlebitis. 

It is better to avoid the application of ultrasound; also in children and adolescents, as well as in the presence of osteoporosis (they can worsen the decalcification of the bone).

Author: Vicki Lezama