Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Moderate to large right pleural effusion with adjacent atelectasis is slightly smaller when compared to previous exam . The left lung remains clear . The cardiomediastinal silhouette is grossly unremarkable . Compression deformity in the lower thoracic spine is unchanged .
    OUTPUT:
    
Right - sided pleural effusion although moderate to large is slightly smaller when compared to previous exam .