What is the typical depth of penetration for a 3 MHz ultrasound frequency?

What is the typical depth of penetration for a 3 MHz ultrasound frequency?

• A. 1-2 cm
• B. 2-3 cm
• C. 3-4 cm
• D. 4-5 cm

Answer: (A)

High-frequency ultrasound travels less deeply because it is absorbed more quickly by tissue. At 3 MHz, the energy is focused in superficial tissues, roughly about 1 to 2 centimeters beneath the skin. That’s why 3 MHz is chosen for superficial targets like near-surface tendons rather than deeper structures. If you need to reach deeper tissues, a lower frequency—around 1 MHz—would be used, which can reach roughly 3 to 5 cm. So the typical depth for 3 MHz is 1–2 cm.

High-frequency ultrasound travels less deeply because it is absorbed more quickly by tissue. At 3 MHz, the energy is focused in superficial tissues, roughly about 1 to 2 centimeters beneath the skin. That’s why 3 MHz is chosen for superficial targets like near-surface tendons rather than deeper structures. If you need to reach deeper tissues, a lower frequency—around 1 MHz—would be used, which can reach roughly 3 to 5 cm. So the typical depth for 3 MHz is 1–2 cm.