Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . The lungs are well expanded and clear without focal consolidation , pleural effusion , or pneumothorax . Heart size is upper limits of normal . Mediastinal silhouette and hilar contours are normal . Median sternotomy wires are intact . No displaced rib fracture is identified . There is no free air under the diaphragm . med sternotomy
    OUTPUT:
    
No evidence of acute intrathoracic injury . If clinical concern for rib fractures is high , CT is more sensitive .