Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: 1 there are low lung volumes . There is subsegmental atelectasis at both lower lobes . There are small bilateral pleural effusions . There is mild pulmonary vascular redistribution . The cardiac silhouette is upper limits normal in size . There is retrocardiac opacity that could be due to volume loss / infiltrate / effusion .
    OUTPUT:
    
Mild CHF . An underlying infectious infiltrate in the left lower lobe can not be excluded .