Which artifact appears as a grainy texture in ultrasound images due to interference?

Which artifact appears as a grainy texture in ultrasound images due to interference?

• A. Speckle
• B. Shadowing
• C. Mirror Image
• D. Lobes

Answer: (A)

Speckle is the grainy texture you see in ultrasound images, caused by interference of echoes from many small scatterers within the tissue. Each pixel results from summing signals from countless tiny structures; their randomly varying phases cause some echoes to reinforce and others to cancel, producing a granular appearance. This interference pattern is intrinsic to ultrasound imaging and can affect contrast and resolution, though it also carries some natural tissue texture information. Other common artifacts have different appearances: shadowing shows up as dark areas behind highly attenuating objects, a mirror image looks like a duplicated structure created by strong reflections, and lobes create ghost images from energy that radiates outside the main beam. Speckle’s grainy look is distinct because it arises specifically from interference of many sub-resolution scatterers.

Speckle is the grainy texture you see in ultrasound images, caused by interference of echoes from many small scatterers within the tissue. Each pixel results from summing signals from countless tiny structures; their randomly varying phases cause some echoes to reinforce and others to cancel, producing a granular appearance. This interference pattern is intrinsic to ultrasound imaging and can affect contrast and resolution, though it also carries some natural tissue texture information. Other common artifacts have different appearances: shadowing shows up as dark areas behind highly attenuating objects, a mirror image looks like a duplicated structure created by strong reflections, and lobes create ghost images from energy that radiates outside the main beam. Speckle’s grainy look is distinct because it arises specifically from interference of many sub-resolution scatterers.