History of ultrasound in medicine

The first written document dealing with the use of waves in spatial orientation dates back to 1794, when an Italian physicist Lazaro Spallanzani (“Opus coli di fisica”), analyzed the basic mechanisms of the navigation of flying bats in the dark, and rightly deduced that bats employed sound rather than light to orient themselves .

It was in 1880 when Galton created and produced the apparatus that was able to produce the sound waves of a frequency of 40 hertz. The same year, the brothers Jacques (1856-1941) and Pierre Curie (1859-1906) noted that electricity may be created in a crystal of quartz under mechanical vibrating . This phenomenon was termed the piezoelectric effect. The Curie brothers also discovered the inverse piezoelectric effect, the ability of the liquid crystal to produce electricity under the vibrations produced by the ultrasound wave.

Following the tragic sinking of the Titanic in 1912, scientific efforts were instigated to develop a system to visualize underwater structures . The French government, during the First World War, commissioned Paul Langevin, a French physicist, and colleagues, to research the use of high-frequency sound waves to find German submarines. Although their efforts were ultimately unsuccessful, the U.S. Navy was able to develop SONAR (SOund Navigation And Ranging) on the back of Langevin's studies.

In 1928, SY Sokolov, a Soviet physicist, first proposed the idea of ultrasound to find flaws deep in metal structures. Indeed the successful use of ultrasound in industry predated its introduction into clinical medicine. These early sonographic methods in industrial manufacture used "through transmission". A receiver on the opposing side of the material to the ultrasound transmitter detected the sound waves as they passed through the material under testing, creating 'shadows' that could be interpreted.

During the 1940s, efforts to use reflective techniques were made, which of course required that the receiver was on the same side of the material as the transmitter. Donald Sproule, a researcher working in England in 1941 created a system in which the receiver was a separate device collecting the waves that had bounced off the material. In 1944, Floyd Firestone, working in the US, received a patent for the Reflectoscope, the first system in which the same transducer both generated the ultrasound waves, and also detected the reflected waves, in the time between transmitted wave pulses.

In 1947-1948, Karl Dussik, an Austrian physician, and his brother Friederick, a physicist, introduced hyperphonography, a technique which used ultrasound to visualize the cerebral ventricles. Unfortunately, W Guttner, working in Germany showed that the apparent 'pictures' of ventricles were nothing of the kind, but instead represented densities of different parts of the overlying skull!

George Ludwig, working at the Naval Military Research Institute, in the United States, in 1949, carried out research into gallstones embedded in soft tissues, using a through transmission technique. His pioneering investigations into the interactions between ultrasonic waves and animal tissues, helped lay the foundations for the later successful use of ultrasound in medical practice.

Ian Donald introduced the ultrasound in diagnostic and medicine in 1956, when he used the one-dimensional A-mode (amplitude mode) to measure the parietal diameter of the fetal head. Two years later, Donald and Brown presented the ultrasound image of a female genital tumor. Brown invented the so-called “two-dimensional compound scanner”, which enabled the examiner to visualize the density of the tissue, which is often referred to as the turning point in the application of ultrasound in medicine.

The commercial use of ultrasound devices dates back to 1963 when the B mode (“brightness mode”) devices were constructed, enabling the examiner to visualize the two-dimensional image. In the mid-seventies, the “grey scale” was introduced (Kossoff, Garrett) leading to the introduction of the real-time ultrasound scanners. A decade later the Doppler effect served as the basis for the construction of the device that enabled the visualization of blood circulation, color flow Doppler ultrasound.