Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is probable background hyperinflation / COPD . The cardiomediastinal silhouette is enlarged . There is mild pulmonary vascular congestion . There is increased retrocardiac opacity . While this could represent atelectasis , the differential diagnosis includes infection or aspiration . Minimal atelectasis at the right base is also present . No gross effusion .
    OUTPUT:
    
1 . COPD and cardiomegaly . 2 . Mild vascular plethora consistent with mild CHF . 3 . Patchy opacity left base consistent with atelectasis , the differential diagnosis includes infectious infiltrate or changes due to aspiration .