Describe the basic principles of ultrasound imaging (2 marks)
Ultrasound is any frequency above that of human hearing - around 20 kilohertz.
Ultrasound imaging works by emitting a known intensity of ultrasound at a specific frequency, and capturing the reflected sound from whatever is being imaged.
At each boundary between different materials (whether manufactured or living tissues), a certain percentage of the ultrasound is transmitted and a certain percentage reflected.
By calculating the time between emission and the return of the reflected wave, the distance of that boundary can be found.
AG
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