Lesion localization using the scroll bar on tomosynthesis: Why doesn't it always work?

The scroll bar on digital breast tomosynthesis (DBT) is an important tool that facilitates localization of lesions on the orthogonal view. While this works well most of the time, occasionally the location of the lesion as directed by the scroll bar is seemingly inaccurate. There are five important reasons why the scroll bar indicator may suggest a contradictory lesion location. Understanding specific scenarios when this may occur will aid the reader in reconciling these differences.