12 Point Ultrasound

1. Piezoelectric effect discovered in 1880 by Curie.

2. Submarines first used SONAR in 1916.

3. Introduced medically in 1960.

4. Utilizes “acoustic reflection” at tissue interfaces.

5. Using a probe the machine transmits high frequency sound pulses into tissue. Screen forms a 2D image of echoes.

6. Probe detects any reflected waves.

7. Distance from tissue to probe is calculated from these waves using the speed of sound in tissue (5,005 ft/second or 1,540m/s)

8. Sound waves cause particles to collide, compress and disperse.

9. Ultra sound transducer frequency = 1-20 MHz.

10. Audible sound range is 15 Hz – 20 MHz.

11. Increased frequency of sound waves will:

1. Improve resolution

2. Collimate and direct the beam

12. Higher frequencies are used for smaller objects (eye)

Category: Radiology Notes