To focus the ultrasound beam at greater depths, which element characteristic should be increased?

• A. Increase the thickness of the element
• B. Increase the diameter of the element
• C. Decrease the width of the element
• D. Increase the curvature of the element

Answer: (B)

Expanding the transducer’s aperture is what lets you focus deeper. The element’s diameter acts like a lens: a larger aperture provides a wider path over which the wavefront can converge, so the focus can occur farther from the transducer while also reducing beam spread at depth. Changing thickness mainly alters resonance and impedance, not where the beam focuses. Making the width smaller tightens the aperture and moves the focus shallower. Increasing curvature (more curved surface) also brings the focal point closer, not farther. So, increasing the diameter best enables focusing at greater depths.