Equipment, Devices and Therapeutic ModalitiesDifficulty 3/5
Which ultrasound frequency penetrates deeper tissue, and what depth does it target?
- A1 MHz, targeting tissue at approximately 3 to 5 cm depth
- B3 MHz, targeting superficial tissue at 1 to 2 cm depth
- C1 MHz, targeting superficial tissue at 1 to 2 cm depth
- D3 MHz, targeting tissue at approximately 3 to 5 cm depth
Show answer and rationale
Correct: A. Lower frequency penetrates deeper: 1 MHz reaches roughly 3 to 5 cm, while 3 MHz is absorbed more superficially at about 1 to 2 cm.
- D — 3 MHz is absorbed superficially and does not reach 3 to 5 cm.
- B — The depth is right for 3 MHz but the question asks which penetrates deeper.
- C — 1 MHz is the deeper option, not the superficial one.