Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Assessment is slightly limited due to patient rotation . Mild enlargement of the heart is present . Mediastinal and hilar contours are unremarkable . Small left pleural effusion is noted with associated left basilar opacity likely reflecting compressive atelectasis . No pneumothorax or right - sided pleural effusion is present . Degenerative changes are seen in the imaged thoracic spine . Deformity of the right third rib likely reflects an old healed fracture .
    OUTPUT:
    
Small left pleural effusion with associated left basilar opacity likely reflecting atelectasis , although infection is difficult to exclude .