Purpose : Using dynamic range compression (DRC) processing, this study compared the detectability of mediastinal lines by conventional film screen rediography (FS) and by storage phosphor digital radiography(DR). Materials and Methods : We selected 200 normal consecutive chest radiographs (100 FS, 100 DR) ; dynamic range compression was applied to DR processing and moving grids were used in both systems. Seven mediastinal lines (left paraspinal, right paraspinal, azygoesophageal, left para-aortic, posterior junctional, anterior junctional and right paratracheal) were scored from 0 point to 3 point (0:not visible, 1:suspiciously visible, 2:visible, but not clear, 3:clearly visible) according to visibility and sharpness, as agreed by a radiologist and a resident. The differences between the two modalities were compared and analyzed by chi-square test. Results : Among the 1400 mediastinal lines analyzed, 419 lines by DR(59.9%) and 232 lines by FS(33.1%) were scored more than 2 points. In all mediastinal lines except the left para-aortic, DR was more detectable and clearer than FS, with statistical significance(p<.01). Conclusion : DR processed with DRC visualizes mediastinal lines more frequently and clearly than conventional FS, and is therefore thought to be useful for the evaluation of mediastinal diseases.