What is the effect of using a higher frequency on attenuation and imaging depth?

• A. Lower frequency reduces imaging depth
• B. Higher frequency increases attenuation and reduces imaging depth
• C. Frequency has no effect on attenuation
• D. Higher frequency reduces attenuation

Answer: (B)

Using a higher frequency increases attenuation, meaning the ultrasound beam loses more energy per centimeter as it travels. This happens because absorption and scattering rise with frequency, so the attenuation coefficient in soft tissue grows roughly with frequency. As a result, echoes from deeper structures become weaker and may fall below the detectable threshold, shortening the maximum imaging depth. At the same time, higher frequency improves spatial resolution due to the shorter wavelength, giving crisper detail at shallow depths. The practical takeaway is the trade-off: higher frequency gives better detail but penetrates less deeply; lower frequency travels farther but with less resolution.