Banding artifacts are most directly caused by an error in which imaging control setting?

• A. Depth
• B. Focus
• C. TGC
• D. Master gain

Answer: (C)

Banding artifacts arise when the receiver gain changes with depth in an uneven way, creating horizontal stripes of alternating brightness. This happens because the signals coming from different depths are amplified differently, so abrupt changes in that depth-dependent gain show up as bands across the image. Time Gain Compensation is the control that shapes how much amplification is applied at various depths to compensate for attenuation as the ultrasound waves travel deeper. If the TGC curve is set incorrectly or has abrupt steps between depth zones, those brightness differences appear as bands. Other controls don’t produce this pattern: depth sets how far you image and doesn’t create depth-dependent brightness bands; focus affects where along the depth the image is sharp; master gain changes brightness uniformly across all depths. So the setting most directly responsible for banding is the time gain compensation.