Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear stable . The left atrial appendage appears enlarged . There is persistent moderate blunting of the left costophrenic sulcus , suggestive of an effusion and unchanged . There is no evidence for effusion on the right side . Alternatively , this may be due to chronic pleural thickening . Patchy right basilar density is similar to the earlier radiographs . On this study , the lateral view suggests new posterior density , probably in the left lower lobe , not specific but suggestive of developing pneumonia , however .
    OUTPUT:
    
Increasing posterior density in the left lower lobe raising concern for developing pneumonia , although the area is difficult to assess .