Which kind of waves are used in sonography?
Ultrasonic waves
The explanation for the correct option:
Ultrasonic waves:
Sound waves of very high frequency, higher than 20 kHz are called ultrasonic waves or ultrasound. These waves are able to travel along well-defined paths even in the presence of obstacles, hence finding wide applications in industries and the medical field. Certain animals like dolphins, bats, and porpoises emit these rays to find their prey.
2. Ultrasonic waves are used to find defects in huge structures like buildings, bridges, machines and also scientific equipment. If the waves are passed through the structures, they get reflected back indicating the presence of the flaw or defect.
3. Reflecting ultrasound waves from body parts because of the varying density of the tissue helps doctors to detect faults in different organs. ‘Echo-cardiography’ technique uses these waves to analyze the working of the heart. The ultrasonography technique develops images of body parts with the help of electrical signals generated from reflected ultrasonic waves.
4. Ultrasonic waves help doctors to detect abnormalities in body parts, such as stones in the gall bladder and kidney or tumors in different organs by developing an image of the part with the help of electrical signals generated from reflected ultrasonic waves.
The explanation for incorrect options:
Options A, B, and C are energy waves that have wide applications in different fields but are not suitable for sonography.
Hence, option (D) is correct