Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Linear atelectasis in the lower lungs noted . No convincing evidence for pneumonia or edema . No large effusion or pneumothorax . Heart appears top - normal in size . The mediastinal contour is normal . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
No signs of pneumonia .