Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is an opacification seen posterior to the heart which likely reflects the descending aorta . There is no pleural effusion or pneumothorax . The cardiac and mediastinal contours are normal . The hilar and pleural structures are unremarkable . The imaged upper abdomen is normal . There is no acute osseous abnormality .
    OUTPUT:
    
No acute cardiopulmonary process .