Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . The mediastinal and hilar contours appear within normal limits . There is no pleural effusion or pneumothorax . There is slight volume loss at the left lung base with relative elevation of the left hemidiaphragm and streaky opacification suggesting minor atelectasis . Elsewhere , the lungs appear clear . Mild - to - moderate rightward convex curvature is centered along the lower thoracic spine .
    OUTPUT:
    
Patchy left basilar opacification , most likely due to minor atelectasis and volume loss .