Purpose: Portable chest x-ray (PCXR) is commonly employed in intensive care units (ICU). CXR provides valuable information but is hindered by structural overlap. Digital chest tomosynthesis (DCT) removes overlap, yielding quasithree-dimensional images. Spatially distributed x-ray source arrays eliminate complex mechanical motion and are wellsuited for mobile systems. The purpose of this study is to design and optimize a compact and portable DCT system employing a linear field emission x-ray source array in lieu of a conventional moving source, balancing image quality with size and clinical practicality.Methods: A prototype stationary DCT system was used to test a variety of system configurations. Tomosynthesis scans of an anthropomorphic phantom were performed repeatedly to generate an image ensemble. Subsets were selected for reconstruction to investigate the impact of spatial distribution on image quality. Reconstruction slice images were evaluated by visualization of simulated lung nodules and presence of artifact to determine the optimal source configuration.Results: Reconstruction slice images demonstrated out-of-plane artifact in configurations with low projection image density. Narrow angular span compromised the visualization of structures and low contrast features. Of the evaluated configurations, one was determined to best balance image quality with physical constraints, utilizing 15 projections covering an angular span of 23 degrees.Conclusion: Bedside 3D imaging is achievable by use of x-ray source arrays. A configuration was determined that generates good image quality in a size conducive to design of a mobile tomosynthesis system. Such a system should provide increased clinical utility compared to 2D radiography in the ICU.