Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is no pleural effusion or pneumothorax . Heart size is normal . Mediastinal silhouette is unchanged and unremarkable . The lungs are clear . No definite rib fracture is seen . No definite displaced rib fracture is seen . Degenerative changes of the lower thoracic spine are noted . The bones are diffusely osteopenic . Calcifications are seen within the aortic arch .
    OUTPUT:
    
No evidence of acute intrathoracic process .