What depth is typically reached with 1 MHz ultrasound?

What depth is typically reached with 1 MHz ultrasound?

• A. 1-2 cm
• B. 3-4 cm
• C. 0.5 cm
• D. 5 cm

Answer: (D)

The depth of penetration is mainly determined by the ultrasound frequency: lower frequencies travel deeper before being absorbed. For therapeutic 1 MHz ultrasound, the energy typically reaches around 3–5 cm into soft tissue, with many sources citing about up to 5 cm as a practical maximum. This is why 1 MHz is used when deeper tissues are the treatment target. In contrast, higher frequencies (like 3 MHz) are absorbed more quickly and tend to affect only about 1–2 cm beneath the surface. While the exact depth depends on tissue type, coupling, and settings, 5 cm represents the typical depth associated with 1 MHz.

The depth of penetration is mainly determined by the ultrasound frequency: lower frequencies travel deeper before being absorbed. For therapeutic 1 MHz ultrasound, the energy typically reaches around 3–5 cm into soft tissue, with many sources citing about up to 5 cm as a practical maximum. This is why 1 MHz is used when deeper tissues are the treatment target. In contrast, higher frequencies (like 3 MHz) are absorbed more quickly and tend to affect only about 1–2 cm beneath the surface. While the exact depth depends on tissue type, coupling, and settings, 5 cm represents the typical depth associated with 1 MHz.