Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is not enlarged . Aorta is minimally unfolded . There is no CHF . Minimal hazy retrocardiac opacity likely relates to left base atelectasis . No frank consolidation is identified . Elsewhere , no focal opacity is seen . Small focus of subsegmental atelectasis noted at the right lung base . . No pleural effusion . No pneumothorax detected .
    OUTPUT:
    
Mild hazy opacity in the retrocardiac region , question due to atelectasis , though an early infectious infiltrate or area of aspiration pneumonitis could have a similar appearance . If clinically indicated , a lateral view could help for further characterization . Otherwise , no acute pulmonary process identified .