Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is mildly enlarged . A small hiatal hernia is noted . The aorta is mildly tortuous . Hilar contours are unremarkable . Rounded opacity within the posterior right lower hemithorax may reflect a focal diaphragmatic hernia , and appears unchanged from the previous radiograph . Remainder of the lungs are clear without focal consolidation . There is minimal subsegmental atelectasis in the left lung base . Pulmonary vasculature is normal . No pleural effusion or pneumothorax is identified no acute osseous abnormalities demonstrated . Dense material within the colon likely reflects oral contrast material .
    OUTPUT:
    
No acute cardiopulmonary abnormality . Unchanged rounded opacity within the posterior right lower hemithorax , possibly a focal diaphragmatic hernia .