Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable frontal chest radiograph obtained in the upright position excludes the right costophrenic angle . Otherwise , the lungs are clear without effusion or pneumothorax . The heart size is normal . The mediastinal contours are unremarkable . A radiopaque density overlies the right upper quadrant , likely external , please correlate clinically .
    OUTPUT:
    
No acute cardiopulmonary pathology .