Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . The aortic arch is partly calcified . The mediastinal and hilar contours appear unchanged . There is no pleural effusion or pneumothorax . The lungs are clear aside from minimal right basilar atelectasis or scarring . Moderate degenerative changes are noted along the lower thoracic spine . There is partly visualized irregularity along the right acromioclavicular joint and possibly acro-osteolysis , which does not appear present on the left side . This appearance could be post-traumatic , noting asymmetry . There is no evidence of rib fracture .
    OUTPUT:
    
No evidence of acute disease .