Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . Left costophrenic angle and hemidiaphragm are obscured , suggestive of moderate pleural effusion . Adjacent opacity is also noted . Right lung is clear . Hilar and mediastinal silhouettes are unremarkable . Heart size can not be accurately assessed due to adjacent pleural effusion . There is no pulmonary edema . Partially imaged upper abdomen is unremarkable .
    OUTPUT:
    
Moderate left pleural effusion with adjacent opacity , which may represent atelectasis or infection in the appropriate clinical setting .