MRI has no effect on the thyroid gland, because the working principle of MRI is that the human body is in a strong magnetic field, the water molecules in the body resonate in the magnetic field, the resulting signal is received by the machine, and the computer recomposes the signal into an image, because there is no radioactivity, so there is no harm to the body, and adults, children, and women in the second trimester of pregnancy are able to do it, so there is no effect on the thyroid gland. The thyroid gland is not affected. The patient’s body can not contain iron, nickel and other substances that may form magnetic properties, otherwise it will cause damage to the body, but the titanium alloy has no effect. Patients with hyperthyroidism or goiter will not be affected, and it will not worsen the disease or increase the size of the goiter.