Radiology The ultrasonic sound waves employed in ultrasound machine for medical sonography have the frequency of A 2 - 20 MHz B Less than 1 MHz C 20-20,000 Hz D Greater than 100 MHz 💡 Explanation The ultrasonic sound waves employed in ultrasound machine for medical sonography have the frequency of ✓ Correct Answer: A. 2 - 20 MHz