If a high-density shadow is present on a chest X-ray, it is important to determine its location. If the hyperdense shadow is present in the lung field, you need to differentiate an intrapulmonary lesion from a foreign body outside the lungs; an intrapulmonary lesion may be a soft tissue nodule or soft tissue mass, or it may be a calcified focus. If it is something outside the lung field, it may be a lesion outside the lung field or something on clothing. If the hyperdense shadow is present in the soft tissue of the chest wall or in the trachea, consider whether it is a foreign body in the trachea or the presence of a foreign body in the soft tissue of the chest wall that is causing the hyperdense shadow. Therefore, it is important to determine the different sites of hyperdense shadows in chest radiographs.