Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable frontal view of the chest demonstrates low lung volumes . There is no pneumothorax . The left costophrenic angle is obscured , suggestive of a small pleural effusion . Retrocardiac opacity is noted , more conspicuous from prior exam . There is no right pleural effusion . There is apparent thickening of the minor fissure . Calcified lymph nodes within the AP window are again noted . The hilar and mediastinal silhouettes are unchanged . The heart size is top normal . There is no pulmonary edema . Port - A - Cath tip projects over cavoatrial junction . Partially imaged upper abdomen is unremarkable .
    OUTPUT:
    
Retrocardiac opacity is more conspicuous from ___ exam , which likely represents atelectasis or infection in the appropriate clinical setting . Possible small left pleural effusion .