Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiographs were obtained . Patchy linear opacities at both lung bases persist but are somewhat less apparent compared to the studies in the preceding week . There is no new consolidation , effusion , or pneumothorax . Cardiac , mediastinal , and hilar contours are unremarkable .
    OUTPUT:
    
Improving bibasilar opacities , likely atelectasis .