What is the source of the echoes depicted by the arrows in this image of the kidney?

What is the source of the echoes depicted by the arrows in this image of the kidney?

• A. Side lobes
• B. Grating lobes
• C. Refraction
• D. Reverberation

Answer: (D)

Reverberation artifacts come from the ultrasound pulse bouncing back and forth between two strong reflectors, producing multiple, evenly spaced echoes along the beam. In this kidney image, the arrows show echoes that arise not from real structures but from these repeated reflections between a strong surface (often the transducer interface and a nearby boundary). That’s why this is best explained by reverberation. Side lobes and grating lobes would show off-axis echoes from outside the main beam, refraction would bend or displace structures, but wouldn’t create a straight train of echoes along the beam like reverberation does.

Reverberation artifacts come from the ultrasound pulse bouncing back and forth between two strong reflectors, producing multiple, evenly spaced echoes along the beam. In this kidney image, the arrows show echoes that arise not from real structures but from these repeated reflections between a strong surface (often the transducer interface and a nearby boundary). That’s why this is best explained by reverberation. Side lobes and grating lobes would show off-axis echoes from outside the main beam, refraction would bend or displace structures, but wouldn’t create a straight train of echoes along the beam like reverberation does.