临床上，为增强CT扫描效果，常需使用造影剂。以往使用的多为离子型（高渗）造影剂泛影葡胺。但是，由于这类造影剂输往速度快，剂量大，浓度高，故易发生过敏反应及毒副作用。近年来，非离子型（低渗）造影剂问世，为临床上合理选用碘造影剂提供了更多的可能性和灵活性c国内外 Clinically, in order to enhance the CT scan results, often need to use contrast media. In the past mostly used for ionic (hypertonic) contrast agent diatrizoate meglumine. However, due to the delivery of such contrast agent fast, large dose, high concentration, it is prone to allergic reactions and toxic side effects. In recent years, the advent of non-ionic (hypotonic) contrast agent, the clinical rational use of iodine contrast agent provides more possibilities and flexibility c at home and abroad