Which statement is true about increasing frequency in ultrasound imaging?

• A. It increases tissue exposure
• B. It does not increase exposure
• C. It decreases tissue exposure
• D. It guarantees higher resolution

Answer: (B)

Raising frequency changes how the beam behaves, not how much energy is put into the tissue. Higher frequency improves image detail because shorter wavelengths give better resolution, but it also attenuates more quickly, limiting how deep the sound can travel. The amount of energy that tissue receives—the exposure—depends mainly on how much acoustic power is emitted and for how long the beam is on. If you keep the output power and pulse duration the same, simply using a higher frequency does not automatically increase the energy delivered to tissue. So, in this context, increasing frequency does not inherently raise exposure.