Which artifact involves the sound beam bouncing off multiple reflectors before returning?

Which artifact involves the sound beam bouncing off multiple reflectors before returning?

• A. Multipath artifact
• B. Side lobe artifact
• C. Ring-down
• D. Acoustic shadow

Answer: (A)

Multipath artifact is about the ultrasound energy taking more than one path back to the transducer. When the sound beam encounters reflectors that cause successive reflections, the echoes can return along different routes and at different times. The ultrasound system then mixes these multiple return paths, which can make structures appear at incorrect depths, duplicated, or distorted. This exact situation—the beam bouncing off several reflectors before returning—produces the multipath effect. The other artifacts don’t fit as well. Side lobe artifact comes from energy that leaks out of the sides of the main beam and creates off-axis echoes, not echoes from multiple return paths. Ring-down is a persistent, resonant ringing after the pulse, often from gas bubbles or metallic objects, not a path-length issue. Acoustic shadow is a dark area behind a highly attenuating object, due to blocked deeper echoes, not multiple return routes.

Multipath artifact is about the ultrasound energy taking more than one path back to the transducer. When the sound beam encounters reflectors that cause successive reflections, the echoes can return along different routes and at different times. The ultrasound system then mixes these multiple return paths, which can make structures appear at incorrect depths, duplicated, or distorted. This exact situation—the beam bouncing off several reflectors before returning—produces the multipath effect.

The other artifacts don’t fit as well. Side lobe artifact comes from energy that leaks out of the sides of the main beam and creates off-axis echoes, not echoes from multiple return paths. Ring-down is a persistent, resonant ringing after the pulse, often from gas bubbles or metallic objects, not a path-length issue. Acoustic shadow is a dark area behind a highly attenuating object, due to blocked deeper echoes, not multiple return routes.