Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patchy left lower lobe opacity may be due to atelectasis or pneumonia . No focal consolidation is seen on the right . No pleural effusion or pneumothorax is seen . Cardiac silhouette is top - normal to mildly enlarged . Mediastinal contours are unremarkable .
    OUTPUT:
    
Patchy left lower lobe opacity is subtle and may represent atelectasis or pneumonia .