Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable upright frontal view of the chest shows no free air under the diaphragm . The lungs are clear . There is no pleural effusion , pneumothorax or focal airspace consolidation . The cardiac and mediastinal contours are normal . The hilar structures are unremarkable .
    OUTPUT:
    
No free air under the diaphragm .