3-year-old baby for MRI does not cooperate, should cooperate with the doctor in advance to let the baby take sedative drugs. Magnetic resonance imaging is enough to clearly display the diseased tissue, reflecting the physiological and biochemical information in the function and metabolic process of living tissues, and plays a very great role in the definitive diagnosis of clinical diseases, the selection of treatment plans and the assessment of prognosis. However, MRI scanning time is relatively long, for children who can not actively cooperate with the examination will need to use drugs for sedation. If a 3-year-old baby is not cooperating with the MRI, give the baby an amount of sedative medication based on his or her weight 30 minutes before the exam and wait until the baby is asleep. It is important for parents to follow the doctor’s instructions for the period of time before sedation medication is given. It is important that each sedated child be awake for a period of time before the sedation is given, as this will help the examination to go smoothly. During the sedation period, you need to pay attention to your baby’s breathing, heart rate and other general conditions.