Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest demonstrate well - expanded and clear lungs . Cardiomediastinal silhouette is stable . There is no pleural effusion or pneumothorax . There is no pulmonary edema . Degenerative changes in the spine and old rib fractures are noted .
    OUTPUT:
    
No acute intrathoracic abnormality .