Ultrasounds

Question 1

Explain the uses of ultrasounds

Answer 1

1. Baby, liver, bladder scans as they consist of soft tissues
2. Used to determine blood flow speeds through use of colour Doppler.

Question 2

Explain how ultrasounds are produced.

Answer 2

1. Piezoelectric crystal has AC applied across it, causing it to vibrate over 20kHz to create an ultrasound.
2. Ultrasound bounces back off an organ when there is a difference in tissue density, elasticity and/or texture.
3. It hits the piezoelectric crystal again in which the ultrasound then causes the piezoelectric crystal to vibrate, thereby producing an AC.
4. By measuring frequency and time between signals, a computer can produce images, calculate speeds and calculate depths.
5. Ultrasound scans send ultrasound waves and pick up the waves that are bounced back.