Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The aorta is mildly tortuous . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is not engorged . Minimal linear and patchy opacities are seen in the lung bases likely reflective of atelectasis . No focal consolidation , pleural effusion or pneumothorax is present . There are moderate degenerative changes seen within the imaged thoracic spine .
    OUTPUT:
    
Mild bibasilar atelectasis .