The following should be noted for head-enhanced CT: 1. Remove earrings, hairpieces, adhesive bands, etc.; 2. Set your head straight, keep your jaws inward, and do not move around; 3. Pay attention to fasting; 4. If the patient is in a state of pregnancy preparation or already pregnant, or if there is iodine allergy, severe liver and kidney function impairment, thyroid disease, allergic constitution, or advanced malignant tumor, it is not recommended to do head-enhanced CT; 5. Do not leave in a hurry, but stay in the observation room for 15 minutes, and if there is no adverse reaction, you can leave. After the examination is completed, drinking more water can make the contrast agent discharged from the body in time.