Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes cause bibasilar atelectasis and bronchovascular crowding . Allowing for this , airspace opacities in the right lung base and retrocardiac region may represent atelectasis or early consolidation . There is no pleural effusion , pulmonary edema , or pneumothorax . The cardiomediastinal silhouette is within normal limits . No evidence for pneumoperitoneum .
    OUTPUT:
    
1 . Low lung volumes . 2 . Bibasilar airspace opacities may represent atelectasis or early consolidation , depending upon the clinical setting . 3 . No evidence of pneumoperitoneum .