Chest digital tomosynthesis (chest DTS) has been recently introduced to overcome the limitations for high patient dose of conventional X-ray radiography and of a cone-beam computed tomography (CBCT) in studies of overlap of anatomical structures. In the present study, we constructed chest DTS system with amorphous-silicon (a-Si) digital flat-panel detector with pixel pitch of 143 × 143 μ m2 based upon filtered backprojection (FBP) reconstruction methods We performed both experiments and systematic simulations using our chest DTS system. The image performances were evaluated by means of root-mean-square error (RMSE) and signal difference-to-noise ratio (SDNR) with respect to scan angles such as ± 5̂, ± 10̂, ± 15̂, and ± 20̂. We also performed experiments using our chest DTS system. According to the results, the image performances obtained from chest DTS are improved by using our wide scan angle approach The chest DTS slices showed an improvement in the depth resolution with increasing scan angle. It was found that the optimized filter with a Hanning window to limit the high-frequency components improves image performance because of noise reduction. The chest DTS slices showed an improvement in the depth resolution with increasing scan angle. Both simulation and experimental results showed the same tendency when image performances quantitatively compared. Based on our results, we successfully obtained chest DTS reconstruction images by using a FBP method and promising to application to field of medical imaging.