Applications of ultrasound in medicine

Diagnostics:
This field is probably the most well known and most widely used application of ultrasound. In 1942, neurologist K.-T. Dussik from Vienna, Austria used his "hyperhponography" method to produce the first transmission ultrasound image, or "hyperphonogram", of a human skull (published in the Journal of Neurological Psychiatry 1942). Originally viewed with skepticism, this diagnostic method gained widespread acceptance by the end of the 1950s. The pioneer in the development and production of systems for medical use was, and still is, the Siemens Group of Germany. These days, given greater computational power and optimized scanning methods, we can already produce three or four-dimensional pictures for better differential diagnostics using ultrasound technology (spatial compounding and frequency compounding). Ultrasound diagnostics is considered a highly-developed, reliable, gentle and safe diagnostic method, and we can no longer imagine classical medicine without it.

 

Therapy:
The therapeutic use of ultrasound is essentially based on three different principles of action:
The thermal action – the kinetic energy of the sound inside the tissue is converted into heat when employing ultrasound (molecular collusion). Continuous ultrasound waves are used to produce this effect. With the mechanical action, the sound waves cause vibration in the tissue, which leads to a so-called micro-massage. In physical medicine, pulsed sound waves are used here as well, where no heating effect occurs. The third action is sonophoresis (also known as phonophoresis). This is where the properties of ultrasound are used for transcutaneous (penetrating beneath the skin) transport of active ingredients. Ultrasound optimizes the permeability of tissue structures, thereby transporting active ingredients to deeper regions of the organism than they would otherwise reach by other methods. In dentistry, ultrasound has been used for a very long time as a gentle means of cleaning teeth. Other applications in medicine include eye surgery, separation and fusion of tissue and bone, tumor therapy, tissue cleaning, germ killing and biostimulation at the cellular level. Very recently, in 2009, the first non-invasive brain operation using transcranial high-energy ultrasound technology was performed in Switzerland (Universitätsspital Zurich), under observation with magnetic resonance imaging.