Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomegaly is stable . The aortic arch stent as well as tricuspid and mitral valve hardware are again seen . The pulmonary vasculature is normal . Given the patient 's clinical presentation , linear lucency inferior to the heart is likely air within a loop of bowel rather than pneumomediastinum or pneumoperitoneum . No pleural effusion or pneumothorax .
    OUTPUT:
    
No nodules or signs of infection .