The reasons why metal should not be allowed to come close when doing an MRI may cause damage to the patient, interfere with the images, etc.
1. Damage to the patient: There is a strong magnetic field in the MRI machine and the MRI examination room, which may cause the metal to move, fly towards the instrument or damage the human body, etc. The patient may be injured by the metal. Powerful MRI radiofrequency field can produce thermal effects, causing metal substances to heat up, resulting in local tissue damage to the patient.
2. Interference with images: A stable and uniform magnetic field allows for clear images to be obtained. When metallic substances are present, the uniformity of the magnetic field is affected, resulting in artifacts in the image and affecting the diagnosis of the disease.
Patients need to follow the doctor’s instructions not to bring metal into the magnetic field during the MRI examination, so as not to cause damage to the machine or to the human body or to affect the examination results.