ultrasound
ultrasound — noun
1. sound waves at a frequency too high for the human ear to detect, used in medicin
sound waves at a frequency too high for the human ear to detect, used in medicine to produce images of the inside of the body and in technologies such as sonar for finding objects underwater
Bats send out pulses of ultrasound to find insects in the dark.
collocation: pulses of ultrasound
Doctors use ultrasound to check whether a patient's heart valves are working properly.
use + ultrasound + to-infinitive for examining body parts
Ultrasound can pass through soft body tissues but not through bone.
The submarine crew used ultrasound to map the ocean floor below the ship.
Engineers rely on ultrasound to find tiny cracks inside metal airplane parts.
- sonography
strictly refers to the imaging technique using ultrasound, not the waves themselves; more formal and technical
- ultrasonography
the full medical name for imaging using ultrasound; very formal, rarely used outside clinical writing
- infrasound
sound waves at frequencies below human hearing, the opposite end of the frequency spectrum
用法筆記
Always uncountable when referring to the waves or the general technology. Frequently used as a modifier before another noun (e.g., ultrasound waves, ultrasound therapy, ultrasound equipment).
常見錯誤
2. a medical examination during which organs, a developing baby, or other internal
a medical examination during which organs, a developing baby, or other internal body structures are shown as pictures on a screen using very fast sound vibrations
Leila had an ultrasound at twelve weeks to see her baby's heartbeat.
have + an ultrasound + at [time] for pregnancy
The ultrasound showed that Noa's appendix was swollen and needed urgent care.
Ravi's doctor scheduled an ultrasound of his liver for the following Monday.
Getting an ultrasound is painless because the device only touches the skin.
The hospital bought a new ultrasound machine that gives much clearer pictures.
- ultrasound scan
exactly the same meaning; adds the word 'scan' to make the medical procedure explicit
- sonogram
specifically refers to the image produced by an ultrasound, not the procedure itself; commonly used in American English
- ultrasonography
the formal medical name for the technique; very technical and rarely used in everyday conversation
用法筆記
Countable in everyday contexts: you have an ultrasound (a single examination). Uncountable when referring to the procedure in general: Ultrasound is a safe imaging method. Distinguish from sense 1: sense 2 refers to the examination or its result, not the sound waves themselves.