The idea of using sound to create images is nothing new. In nature, animals like bats and dolphins use a technique called “echolocation” where they emit high-pitched bursts of sound, most of which are inaudible to the human ear. These sound waves bounce off objects in the environment, and the varying speeds by which these reverberations return help the animals to “see” in their sight-restrictive environments. That is why bats can navigate around trees in utter darkness and dolphins can track a single fish in the vast expanse of the ocean. Ultrasonography works in much the same way.
An ultrasound is an imaging method that uses high-frequency sound waves to produce accurate pictures of structures inside the human body, according to Medline Plus. These can be used in a variety of ways, such as recording the development of a fetus inside a woman’s womb, or locating cancerous tumors and other abnormalities. Due to the varying densities and complex composition of the body, ultrasound imagery cannot be used everywhere.
However, it does cover a huge expanse of human health. Echocardiography relates to heart health and gastroenterology examines the solid organs in the abdomen. Neurology deals with the brain and spinal cord and ophthalmology uses sonar to examine the eyes. Obstetrics correlates with female reproductive health and musculoskeletal sonography looks at the tendons, muscles, and bones.
High frequencies, or “ultrasound,” are used as opposed to low frequencies because the sound waves in higher pitches are closer together, while in low pitches, they are spaced further apart. The closeness of the sound waves allows them to bounce back faster and create a more accurate image than lower frequencies would.
To prepare for an ultrasound procedure, the area being examined is typically slathered in a special gel that helps conduct sound waves and improve the clarity of the reading. Air bubbles and other contact problems with the patient’s skin can cause hazy or inaccurate images, so the gel assists in establishing a firm link between the transducer, which emits and reads the sound waves, and the patient’s skin. The ultrasound technician then moves the transducer around until a desirable image can be viewed and interpreted on the monitor. Technicians are trained to look for any abnormalities that the ultrasound may pick up and note these for the patient’s physician. The desired images are then saved for the physician’s viewing later. After the procedure, the gel is easily wiped off the patient’s skin.
Although a non-invasive procedure that requires no discomfort aside from the coldness of the ultrasound gel, ultrasounds should be used with caution in certain situations, such as in obstetrics. It is important that pregnant women take advantage of the technology available today to ensure the health of their baby, but studies have shown that excessive ultrasound procedures, such as in the vanity ultrasound videos being offered today, can result in developmental problems, according to the U.S. Food and Drug Administration. Yet, as long as the procedure is performed by a licensed ultrasound technician and under doctor’s orders, the benefits far outweigh the risks.