Alignment of tomosynthesis systems requires operator skill, particularly where regions of interest are internal structures with limited surface features. Reconstruction of an entire 3D tomosynthesis image may require seconds to minutes, and it can take this long before operators realize that subsequent scans are required. In this time, the patient may have moved and a second scan could also potentially miss the region of interest, requiring a third scan, etc. Multiple exposures are time-consuming and increase patient radiation dose. A digital x-ray tomosynthesis system comprises a static array of x-ray emitters and an x-ray detector and involves selecting a sub-set of x-ray emitters so no x-ray detector part is exposed to x-rays from more than nine of the sub-set and generating a composite image from non-overlapping portions of each respective image produced on the x-ray detector. A two-dimensional image of a subject may be produced using minimal radiation dose.