Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a large retrocardiac opacity which is felt to be secondary to a known large hiatal hernia . The cardiac silhouette is normal . The right hemi thorax and left upper lobe are clear . There is no new focal consolidation . Blunting of the left costophrenic angle is likely secondary to a small left pleural effusion .
    OUTPUT:
    
1 . No acute focal consolidation . 2 . Small left pleural effusion . 3 . Large hiatal hernia .