Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Moderate cardiomegaly is noted , not substantially changed in the interval . The mediastinal contour is similar . Mild pulmonary vascular congestion is demonstrated with perihilar haziness . Retrocardiac focal opacity may reflect an area of pneumonia . Mild atelectasis is also demonstrated in the right lung base . There may be a small left pleural effusion . No pneumothorax is identified .
    OUTPUT:
    
Low lung volumes with retrocardiac opacity concerning for pneumonia . Mild pulmonary vascular congestion and possible small left pleural effusion .