Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are small bilateral pleural effusions . Patchy left base opacity may be due to overlying atelectasis , grossly similar to prior , however aspiration or infection is difficult to exclude . The cardiac and mediastinal silhouettes are grossly stable .
    OUTPUT:
    
Small bilateral pleural effusions . Patchy left base opacity is grossly similar compared to the prior study from 4 days prior , may be due to atelectasis though infection or aspiration are not excluded .