Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a vague retrocardiac opacity , best seen on the lateral projection , which may in the proper clinical setting reflect a developing consolidation . Prominent interstitial markings are noted , likely secondary to chronic parenchymal changes . There is no pleural effusion , pneumothorax , or pulmonary edema identified . The heart size is normal . Mediastinal contours are normal . Multilevel degenerative disease is noted throughout the thoracic spine , without evidence of an acute bony abnormality .
    OUTPUT:
    
Vague , posterior retrocardiac opacity which may reflect an early pneumonia . Findings were conveyed by Dr . ___ to Dr . ___ ___ telephone at 15 : 26 on ___ , 5 minutes after discovery .