Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette is mildly enlarged , unchanged from prior examination with mild tortuosity of the thoracic aorta . This study is somewhat limited due to patient habitus . Hilar contours are unremarkable . There is stable elevation of the left hemidiaphragm with left lung base atelectasis . Lungs are otherwise clear . Pleural surfaces are clear without definite effusion or pneumothorax .
    OUTPUT:
    
No acute cardiopulmonary abnormality .