Scanning the Body Part 1: Ultrasound

Aug 2

Written By Julia Arukakkal- CuriouSTEM Staff

The human body is a complex network of cells that allows us to jump, see, and think. However, injuries to the human body may be hard to see, especially if they are on the inside. This is where diagnostic imaging comes into play. We will be talking about 1 type of diagnostic test, ultrasound.

Ultrasound works by emitting a high frequency sound wave that reflects areas between tissues. Think about a bat using echolocation. When there is a high difference in densities, the ultrasound is reflected, which is shown in the monitor as white. Air next to internal organs would appear white because air is considerably less dense than muscle and fat. In addition, bone next to internal organs would also appear white because bone is considerably more dense than organs. There is also a thick gel applied to the skin on the area the doctor wants to scan. Remember that air would appear white next to tissue. The gel helps ensure that there is minimal air between the probe and the skin.

The probe, which sort of looks like a barcode scanner, emits ultrasound waves and detects it when it reflects back. The reason it can do this is due to the piezoelectric effect, where certain materials, like quartz, change electric energy into kinetic energy- vibrations which emit ultrasound waves. Likewise, it can change kinetic energy, in the form of ultrasound waves causing vibrations, into electric energy. This is useful because when the ultrasound waves are reflected, the changes in electric energy of the quartz can be measured and used to create a computer model of different densities of the human body.

There are also more innovations to expand the uses of ultrasound. For example, bubbles in a saline solution can be injected, which allows for doctors to see whether patients have a hole in their heart through an ultrasound. A hole between the left and the right atrium causes the oxygen rich blood in the left part of the heart, and the oxygen poor blood in the right part of the heart to mix. The bubbles are injected in the vein, a blood vessel that carries oxygen poor blood back to the heart, and removed by the lungs. If bubbles are on the left side, it means that there's a hole. These bubbles could also help deliver medications in the future.

Ultrasound is non-invasive, with no radiation. This allows it to be the primary diagnostic tool with less risk, and more benefits. Through the power of sound waves - this diagnostic tool has the power to diagnose rare conditions and the flexibility to change over time.