An MRI does not necessarily require an injection of medication, depending on what type of MRI the patient is having. If the patient is just having a plain MRI scan, no special preparation is needed and the patient can go straight to the scan. However, if the patient’s other imaging examinations reveal an occupying lesion and need to further clarify the diagnosis, an enhanced MRI is needed, and the patient needs to be injected with MRI contrast agent through a vein, and the patient should have an allergy test for contrast agent before the examination, and the patient’s kidney function should be checked at the same time, because a small number of patients will have an allergic reaction to contrast agent, and patients with poor kidney function are also prone to Nephropathy of contrast agent occurs.