What is Ultrasound and how does it work?

Ultrasound refers to sound waves of such a high frequency (above 20 kHz) as to be inaudible to humans. Ultrasound is non ionizing and is not an electromagnetic radiation. Ultrasound with its short wavelength can be formed into a narrow beam.

 Ultrasound undergoes reflection and refraction at the interface between two different body tissues. It is such reflections or echoes from different tissues that produce the ultrasound images. Diagnostic ultrasound has a special place in imaging soft tissues that are too similar to produce enough x-ray contrast; and also obstetric imaging, as the hazards are perceived to be insignificant compared with x-rays.

How is Ultrasound scanning done?

Ultrasound scanners use probes which painlessly glide over the human body. The probe is hand held by the operator. To eliminate air and ensure perfect contact with the skin, a non staining gel is applied on the scanner probe before the scan starts.

The probe generates and sends out the ultrasound waves and collects the returning echoes. These returning echoes are then converted to images on the monitor screen by the powerful computer inside the scanner.