Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Right - sided central venous line terminates in the low SVC without evidence of pneumothorax . Left base retrocardiac opacity is seen which could be due to atelectasis or confluence of overlying structures , however , underlying consolidation is not excluded in the appropriate clinical setting . The cardiac and mediastinal silhouettes are stable .
    OUTPUT:
    
Subtle left base retrocardiac opacity could be due to atelectasis or overlapping structures , however , underlying consolidation is not excluded in the appropriate clinical setting .