Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A catheter projecting over the stomach appears in unchanged position . Lung volumes are low and there is mild atelectasis at the lung bases bilaterally . No convincing signs of pneumonia , large effusion or pneumothorax . The heart size is difficult to accurately assess in the setting of low lung volumes , though appears grossly unremarkable . Bony structures are intact .
    OUTPUT:
    
Mild bibasilar atelectasis . No convincing evidence for pneumonia .