Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral chest radiograph demonstrate no focal opacity convincing for pneumonia . Heart is within normal limits in size . Mediastinal and hilar contours are unremarkable . There is no pleural effusion or pneumothorax . Visualized osseous structures demonstrate no acute abnormality .
    OUTPUT:
    
No acute intrathoracic abnormality .