1.If it is a foreign body in the body, it is usually due to accidental swallowing or inhalation of small metal objects, such as nails, iron filings, needles, etc., which cannot be eliminated properly in the gastrointestinal or respiratory tract.
2. If it is an instrument, it is usually a medical device or implant used in surgery or other treatments, such as a steel plate or a steel needle. X-rays are a very common imaging method, in which the body is irradiated and visualized by X-ray radiation to see if there is any abnormality in the body part. However, X-ray radiation is harmful to the human body and should be used with caution when necessary and to minimize the number of exposures.