Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lines and tubes are grossly unchanged . The NG to can not be traced through the lower most mediastinum due to underpenetration . The cardiomediastinal silhouette is unchanged . Extensive interstitial and alveolar opacity use in both lungs appear more confluent . Small effusions would be difficult to exclude . No pneumothorax detected .
    OUTPUT:
    
Progression of bilateral opacities , now more confluent , particularly on the left . suggesting progression of alveolar edema . In the appropriate clinical setting , underlying infectious infiltrate would be difficult to exclude .