Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The inspiratory lung volumes are slightly improved from the most recent prior study . Patchy bibasilar airspace opacities likely reflect atelectasis . No focal consolidation concerning for pneumonia , pleural effusion or pneumothorax . The pulmonary vasculature is not engorged and there is no overt pulmonary edema . The cardiac silhouette is normal in size . The mediastinal and hilar contours are within normal limits . Dense calcification of the aortic knob is re-demonstrated . Deformity at the right lateral fourth rib is compatible with healed prior fracture . No acute displaced rib fractures are detected .
    OUTPUT:
    
1 . Probable mild bibasilar atelectasis . 2 . No acute displaced rib fractures but an old healed right lateral fourth rib fracture .