Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiographs are provided . There is a moderate left - sided pleural effusion , new from prior study . Left basilar somewhat linear opacity most likely represents atelectasis . There is no focal consolidation or pneumothorax . Cardiomediastinal silhouette is stable . No acute osseous abnormality .
    OUTPUT:
    
Moderate sized left pleural effusion with probable left basilar atelectasis .