Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Redemonstration of a larger retrocardiac opacification , characterized as a large diaphragmatic hernia on the ___ CT . Adjacent opacification likely reflects atelectasis , though can not exclude infectious process in the appropriate clinical setting . Left costophrenic angle is blunted , reflecting atelectasis or a small pleural effusion . Linear right middle lobe opacification is similar to prior radiograph and correlated with area of atelectasis on concurrent CT . Stable mild enlargement of the cardiac silhouette . Mediastinal and hilar contours are unremarkable . No lytic or blastic lesion identified . There is stable mild vertebral body height loss of mid thoracic vertebrae , unchanged compared to ___ CT .
    OUTPUT:
    
Large retrocardiac opacity likely represents combination of large hiatal hernia and adjacent atelectasis , though can not exclude infectious process in the correct clinical setting . Possible left pleural effusion . Stable mild mid thoracic vertebral body height loss .