It uses ultrasonic waves to image internal organs.
Explanation
Ultrasonography, commonly known as ultrasound imaging, is a non-invasive medical diagnostic technique. It utilizes high-frequency sound waves to visualize internal body structures such as tendons, muscles, joints, vessels, and internal organs.
Option Analysis
- It uses X-rays to image bones. is incorrect: The use of X-rays to image bones refers to Radiography or CT scans. X-rays are electromagnetic waves, whereas ultrasonography uses mechanical sound waves.
- It uses magnetic fields to image soft tissues. is incorrect: The use of strong magnetic fields and radio waves to generate images of soft tissues describes Magnetic Resonance Imaging (MRI), not ultrasonography.
- It uses ultrasonic waves to image internal organs. is correct: Ultrasonography employs ultrasonic waves (sound waves with frequencies above 20,000 Hz, typically between 1 MHz and 10 MHz for medical use). A transducer sends these waves into the body, and they reflect off internal organs and tissue boundaries. The echoes are recorded and converted into visual images.
- It uses infrasonic waves to treat kidney stones. is incorrect: Infrasonic waves have frequencies below the audible range (less than 20 Hz). The treatment of kidney stones, known as Lithotripsy, typically uses high-energy shock waves (often ultrasonic) to break stones, not infrasonic waves. Furthermore, ultrasonography primarily refers to the imaging aspect rather than the therapeutic breaking of stones.
Key Takeaway: Ultrasonography relies on the reflection of ultrasonic waves (frequency > 20 kHz) to create real-time images of internal organs, distinct from X-rays (electromagnetic) or MRI (magnetic fields).