For people who cannot have MRI, the following are specific: 1. have a definite metal placement in the body: such as aneurysm clips, orthopedic metal placements, certain types of pacemakers, metal foreign bodies in the eyes, or some metal foreign bodies in the body. 2. have high fever: because MRI itself will raise the patient’s body temperature. 3. within the third trimester of pregnancy: MRI should be avoided. 4. have claustrophobia: MRI should not be done. 4. claustrophobia: MRI should not be performed. There are some people who should be cautious about having an MRI, such as patients who are unsure of their pacemaker type or patients after the third trimester of pregnancy, depending on the situation, they can choose whether to have an MRI or not.