Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bilateral pleural drains are in unchanged position . Since prior exam , the hazy opacity at the left base has improved , suggesting it is likely positional . Small bilateral pleural effusions are unchanged . A left upper lung zone opacity is unchanged . There is no new opacity , pulmonary edema or pneumothorax . The cardiomediastinal silhouette is normal .
    OUTPUT:
    
No significant change from the prior exam . Persistent bilateral pleural effusions .