What does ultrasound mean?
Ultrasound is sound with frequencies above the range that human beings can normally hear. The word also commonly denotes the medical technique that uses reflected high-frequency sound waves to create images of organs, tissues, and developing babies. During an ultrasound, a handheld device sends sound waves into the body and detects the echoes that return from different structures; a computer converts those echoes into pictures. Ultrasound is widely used in medicine because it is generally painless, non-invasive, and does not use ionizing radiation, unlike X-rays. The same basic principle is applied in industry to inspect materials, detect flaws, and measure distances without making direct contact. In everyday speech, “ultrasound” often means a diagnostic scan, while the technical sense refers to the physical sound waves themselves. Ultrasound belongs to a family of terms built around ultrasonic waves and ultrasonography, the medical discipline that uses these waves to produce diagnostic images.
nounSound waves with frequencies above the range normally detectable by the human ear. In medicine, the term also refers to diagnostic imaging that uses high-frequency sound waves to produce pictures of structures inside the body.
- Sound waves with frequencies above the range of human hearing, used in physical and medical applications.
- A diagnostic imaging examination that uses reflected high-frequency sound waves to produce images of structures inside the body.
"The technician used ultrasound to examine the patient's heart."
"The clinic offered an ultrasound to check the baby's development."
"Ultrasound equipment can reveal defects that are difficult to detect by ordinary inspection."
The plural is used when referring to separate examinations, images, or pieces of equipment, although the singular is also common in general medical contexts.
"The technician performed several ultrasounds during the morning."
Ultrasound turns sound that people cannot hear into detailed images of what is happening inside the body.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does ultrasound come from?
Ultrasound combines the Latin-derived prefix ultra-, meaning “beyond,” with the English word sound, referring to sound waves beyond the usual range of human hearing. The compound was developed during the early 20th century, after the development of high-frequency sound generation and detection made such waves usable for imaging and other applications. Ultrasonic and ultrasonography belong to the same word family: both combine the idea of sound beyond ordinary audible frequencies with Greek sonos, “sound,” or its derivatives.
How ultrasound is actually used
In medical contexts, ultrasound and ultrasound scan are common. Ultrasound imaging is generally non-invasive and does not involve ionizing radiation, although the term is also used informally for the resulting image. Outside medicine, the word usually refers to the sound or to the technology using it.
Easily confused with ultrasound
Ultrasound is sound at frequencies above the human hearing range or an imaging technique that uses it, whereas ultrasonics is the broader field of studying or applying ultrasound.
Ultrasound is the physical sound or the general imaging technology, while ultrasonography is the specific diagnostic process and medical specialty based on producing images with reflected ultrasound.