Which frequency range is associated with diagnostic ultrasound in clinical practice?

Which frequency range is associated with diagnostic ultrasound in clinical practice?

• A. 20 Hz to 20 kHz
• B. 15 to 30 kHz
• C. 2 to 15 MHz
• D. 1 to 3 GHz

Answer: (C)

Diagnostic ultrasound uses high-frequency sound waves in the megahertz range. The frequency determines image detail and depth of penetration: higher frequencies give sharper resolution but don’t travel as far, while lower frequencies penetrate deeper but with less detail. In clinical practice, most diagnostic ultrasound operates around 2 to 15 MHz, which covers imaging for deep organs with lower frequencies and superficial structures with higher ones. The other options fall outside this typical diagnostic range: 20 Hz to 20 kHz is the audible range, not ultrasound; 15 to 30 kHz is ultrasound but at very low frequencies, which would yield poor image quality for medical imaging; and 1 to 3 GHz is microwave-range, not ultrasound.

Diagnostic ultrasound uses high-frequency sound waves in the megahertz range. The frequency determines image detail and depth of penetration: higher frequencies give sharper resolution but don’t travel as far, while lower frequencies penetrate deeper but with less detail. In clinical practice, most diagnostic ultrasound operates around 2 to 15 MHz, which covers imaging for deep organs with lower frequencies and superficial structures with higher ones. The other options fall outside this typical diagnostic range: 20 Hz to 20 kHz is the audible range, not ultrasound; 15 to 30 kHz is ultrasound but at very low frequencies, which would yield poor image quality for medical imaging; and 1 to 3 GHz is microwave-range, not ultrasound.