1 MHz - absorption occurs up to

1 MHz - absorption occurs up to

• A. 2.5 cm
• B. 10 cm
• C. 1 cm
• D. 6 cm

Answer: (D)

Penetration depth in ultrasound is controlled by frequency: lower frequencies lose energy more slowly and reach deeper into tissue, while higher frequencies are absorbed more quickly and don’t penetrate as far. At 1 MHz, the energy can travel through soft tissue to roughly 5–6 cm before absorption reduces the intensity significantly. Therefore, absorption occurs up to about 6 cm. The shallower depths (a few centimeters) align with higher frequencies, and 10 cm would require a much lower frequency than 1 MHz, which isn’t typical for this setting.

Penetration depth in ultrasound is controlled by frequency: lower frequencies lose energy more slowly and reach deeper into tissue, while higher frequencies are absorbed more quickly and don’t penetrate as far. At 1 MHz, the energy can travel through soft tissue to roughly 5–6 cm before absorption reduces the intensity significantly. Therefore, absorption occurs up to about 6 cm. The shallower depths (a few centimeters) align with higher frequencies, and 10 cm would require a much lower frequency than 1 MHz, which isn’t typical for this setting.