Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Semi-erect portable frontal radiographs through the chest demonstrates clear lungs bilaterally . No focal opacification is identified . The mediastinal and hilar contours are unremarkable . Heart size is normal . There is no pleural effusion or pneumothorax . Visualized osseous structures are without acute abnormalities .
    OUTPUT:
    
No acute intrathoracic abnormality .