“…13,[16][17][18] Attention should also be paid to the diagnosis because, on chest x-ray, button batteries can be mistaken for coins, 11,19,20 electrocardiogram electrodes, or other external objects. 4,21 In this respect, button batteries have typical appearance on lateral radiograph: the step-off sign and, on posterior-anterior view, a double-density or double-ring shadow. 11,[22][23][24] Because most batteries pass spontaneous within 4 days, they can be left in the stomach in an asymptomatic patient, with repeated x-ray after 4 days.…”