What depth is typically reached with 3 MHz ultrasound?

What depth is typically reached with 3 MHz ultrasound?

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

Answer: (B)

When ultrasound frequency is higher, the energy is attenuated more quickly and penetrates less deeply. At a frequency of 3 MHz, the energy is absorbed fairly rapidly by tissues, so it reaches only the superficial layers. Clinically, this frequency is used for treating structures close to the surface, typically around one to two centimeters beneath the skin. This makes it well-suited for superficial tendons, joint surfaces, and subcutaneous tissues. If you needed to treat deeper tissues, you’d use a lower frequency, which can reach greater depths. Options that imply depths like five centimeters would align more with lower frequencies. Deeper-than-typical depths such as three centimeters exceed what 3 MHz usually accomplish, while indeed shallower values around half a centimeter are beyond the typical range for this frequency.

When ultrasound frequency is higher, the energy is attenuated more quickly and penetrates less deeply. At a frequency of 3 MHz, the energy is absorbed fairly rapidly by tissues, so it reaches only the superficial layers. Clinically, this frequency is used for treating structures close to the surface, typically around one to two centimeters beneath the skin. This makes it well-suited for superficial tendons, joint surfaces, and subcutaneous tissues.

If you needed to treat deeper tissues, you’d use a lower frequency, which can reach greater depths. Options that imply depths like five centimeters would align more with lower frequencies. Deeper-than-typical depths such as three centimeters exceed what 3 MHz usually accomplish, while indeed shallower values around half a centimeter are beyond the typical range for this frequency.