What is an advantage of a water-path scanner?

• A. Near-field reverberations are reduced
• B. Penetration is increased
• C. Temporal resolution is improved
• D. Axial resolution is improved

Answer: (A)

Using a water-path coupling creates a smooth, continuous medium between the transducer and tissue, which improves impedance matching and eliminates air gaps. This reduces reflections and clutter that typically occur in the near field, so near-field reverberations are diminished. The cleaner near-field makes the image start more clearly and the superficial structures more reliable to interpret.

Penetration isn’t inherently increased by a water path; depth of imaging mainly depends on frequency and tissue attenuation. Temporal resolution and axial resolution are tied to scan speed and the ultrasound wavelength/bandwidth, respectively, and a water path doesn’t automatically boost those aspects.