Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral radiographs of the chest demonstrate decreased inspiratory lung volumes . There is increased retrocardiac opacification obscuring the left hemidiaphragm consistent with small left pleural effusion and associated atelectasis . In the appropriate clinical setting , underlying consolidation can not be excluded . No focal consolidation is seen in the right lung . No pneumothorax is detected . The cardiac silhouette is enlarged but unchanged . The mediastinal and hilar contours are prominent but unchanged allowing for positional differences . A hiatal hernia is noted on the lateral radiograph . There are multilevel degenerative changes throughout the thoracic spine . The bilateral humeral heads appear high - riding but unchanged from the prior study .
    OUTPUT:
    
Small left pleural effusion with associated atelectasis . In the appropriate clinical setting , underlying pneumonia can not be excluded .