Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are again noted in the patient is rotated to the left . The right lung is clear . Left - sided pleural effusion is again seen as well as rounded opacity projecting over the left lung laterally , previously characterized as rounded atelectasis . Cardiomediastinal silhouette is unchanged although difficult to accurately assess hypertrophic changes no spine .
    OUTPUT:
    
Persistent left - sided pleural effusion and rounded opacity which was more fully characterized on remote prior CT as rounded atelectasis . Presumed left basilar atelectasis noting that infection can not be excluded .