The main precautions for cranial plain scan include: 1. There must not be any foreign objects on the head, such as jewelry, earrings, earrings, necklaces, etc., otherwise these foreign objects will cause artifacts on the CT scan results and affect the accuracy of the results. 2. During the examination, the head must not be shaken, as head shaking will cause poor imaging. Therefore, for patients who are agitated, someone must help hold the head or use sedation when performing CT scan of the head. 3. For some patients who undergo enhanced CT scan of the skull, they must drink more water after the scan, which can promote the excretion of the contrast agent. Cranial CT scan has a very important role in diagnosing many diseases of the skull and brain, and cranial CT scan has the advantages of being fast, short and moderate in cost.