MRI is not recommended for patients who have just finished eating, because MRI is easy to misabsorb, especially for patients with nasal feeding diet and poor digestion, the chance of misabsorption will increase significantly. Patients with magnetism inside the body cannot do MRI, such as pacemaker implantation, internal carotid artery stent implantation, or patients with spatial claustrophobia cannot do MRI, nor can patients who cannot cooperate with lying down or mania in clinical practice.