Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Linear density at the right base likely represents atelectasis . Retrocardiac opacity could represent atelectasis or pneumonia . Heart size is mildly enlarged . Mediastinal contours are exaggerated by low lung volumes . No pleural effusion , pulmonary edema or pneumothorax is detected on these views .
    OUTPUT:
    
Low lung volumes with basilar atelectasis and retrocardiac density , which could represent atelectasis or pneumonia . Findings were reported to ___ by ___ by telephone at 1 : 15 p .m . on ___ at the time of initial review of the study .