Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph was obtained . The lungs are well expanded and clear . There is no focal consolidation , pleural effusion or pneumothorax with mild bibasilar scarring . The heart and mediastinal contours are unremarkable . No displaced rib fractures are identified .
    OUTPUT:
    
No acute intrathoracic process .