CT-enhanced contrast allergy mainly includes: 1. mild reaction: the symptoms are mainly hives, flushing, salivation, sneezing, lacrimation, chest tightness, shortness of breath, nausea and vomiting. Most of them can be relieved by themselves within a short time without special treatment. 2. Severe allergic reactions: mainly manifested as laryngeal and bronchial spasms, which can cause shortness of breath and difficulty in breathing. Angioneurotic edema appears, a large rash, skin mucous membrane bleeding, pulmonary edema, anaphylactic shock, coma, convulsions, etc. The most serious will appear cardiac arrest, requiring emergency treatment. For neurovascular edema, intramuscular injection of 25-50mg of isoprostanes, subcutaneous or intramuscular injection of 0.1% epinephrine 0.5-1ml or 0.5-1.5g of aminophylline for laryngeal or bronchospasm, intravenous injection of 100-400mg of hydrocortisone, or intramuscular injection of 5-10mg of dexamethasone to suppress the allergic reaction in the organism. In addition, oxygen, tracheal intubation, artificial respiration, cardiothoracic compressions, antiepileptic and anti-shock treatment are given according to the situation.