A typical transducer frequency used for penile Doppler duplex ultrasound is?

• A. 2-4 MHz
• B. 8-10 MHz
• C. 12-15 MHz
• D. 20-40 MHz

Answer: (B)

Penile Doppler duplex imaging relies on clearly visualizing the superficial penile arteries, so a high-resolution, shallow-imaging probe is ideal. A transducer in the 8–10 MHz range provides the best balance: it offers excellent spatial resolution to delineate the dorsal and cavernosal arteries and reliable Doppler signals, while still penetrating enough to reach those vessels just beneath the skin. Lower frequencies (like 2–4 MHz) would penetrate deeper but blur small penile vessels, making it harder to assess arterial inflow accurately. Very high frequencies (12–40 MHz) give superb surface detail but lack sufficient penetration for this anatomy and are not routinely used for penile vascular assessment. Thus, 8–10 MHz is the typical choice for penile Doppler duplex.