Which ultrasound frequency provides a depth of 2-3 cm?

Which ultrasound frequency provides a depth of 2-3 cm?

• A. 3 MHz
• B. 1 MHz
• C. 0.5 MHz
• D. 5 MHz

Answer: (B)

Lower frequency ultrasound penetrates deeper because attenuation increases with frequency, so high-frequency waves lose energy more quickly and don’t travel as far. For imaging around 2–3 cm beneath the surface, you want enough depth while keeping usable image quality, which is achieved with a lower frequency probe. A 1 MHz transducer provides that deeper reach, whereas a 5 MHz probe would give better detail but usually only to shallower depths, and a 3 MHz probe sits between—often not as reliable for reaching the full 2–3 cm in all patients. A very low frequency like 0.5 MHz could go deeper but with poor resolution, making the image less useful. So, 1 MHz is the best match for a 2–3 cm depth.

Lower frequency ultrasound penetrates deeper because attenuation increases with frequency, so high-frequency waves lose energy more quickly and don’t travel as far. For imaging around 2–3 cm beneath the surface, you want enough depth while keeping usable image quality, which is achieved with a lower frequency probe. A 1 MHz transducer provides that deeper reach, whereas a 5 MHz probe would give better detail but usually only to shallower depths, and a 3 MHz probe sits between—often not as reliable for reaching the full 2–3 cm in all patients. A very low frequency like 0.5 MHz could go deeper but with poor resolution, making the image less useful. So, 1 MHz is the best match for a 2–3 cm depth.