7 Important Points - Piezoelectricity

1. The crystal within an ultrasound machine is naturally piezoelectric

2. Piezoelectricity is the generation of a change in charge distribution from the introduction of mechanical stress.

1. Crystal under mechanical pressure will produce an electric pulse.

2. Electrodes on crystal surface will transmit and receive these pulses.

3. Near field = Fresnel zone, highly collimated parallel component.

4. Far field = Fraunhofer zone which is divergent.

5. The best Ultra sound images are taken within the transitional zone.

6. The size and frequency of a transducer determines near or far field.

7. The B-mode of ultrasound is the most commonly used mode. The brightness of the blip is equal to the intensity of the echo.

Category: Radiology Notes