Overlapping images reduce which type of artifact when viewing a 3D reformatted image?

The correct choice addresses stair-step artifacts, which are common in 3D reformatted images generated from volumetric data. These artifacts occur when there is insufficient data sampling along the z-axis, leading to a "stair-step" appearance in curved or angled surfaces of the image.

When images are acquired with overlapping slices, the additional data collected helps to fill in gaps between the slices, leading to a smoother and more continuous surface representation in the 3D reconstruction. By incorporating overlapping images, the amount of data available for processing is increased, which significantly reduces the stair-step effect and improves the overall quality of the image.

This understanding highlights the importance of proper technique in image acquisition, particularly in ensuring that slice thickening and spacing are within optimal ranges to minimize this specific type of artifact in 3D imaging.