Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP view of the chest demonstrates low lung volumes , which accentuate bronchovascular markings . There is persistent left lung base heterogeneous opacity , which obscures left hemidiaphragm . There is slight blunting of the left costophrenic angle suggestive of trace pleural effusion . Trace right pleural effusion is also likely . There is no pulmonary edema . Hilar and mediastinal silhouettes are unchanged . Heart size is normal . No pneumothorax .
    OUTPUT:
    
Persistent heterogeneous left lung base opacity , which may represent atelectasis , aspiration or infection in the appropriate clinical setting .