| In contrast-enhanced CT, many kinds of contrast media are administered with an automatically controlled syringe injector whose needle is retained in a peripheral vessel. In such cases, damage to the injection syringe caused by intratube pressure and/or jet flow from the needle may result in injury and pain at the injection site of the vessel. Thus, stable injection including the needle tip is essential. To improve the reliability of injections and to ensure the safety of patients, we evaluated three factors, syringe materials, needles, and contrast media, by measuring intratube pressure. Frictional resistance of the syringe was also evaluated as it relates to syringe configuration. We found that the intratube pressure increased in proportion to the density and viscosity of each contrast medium. However, it was revealed that the pressure itself fluctuated according to the material and configuration of each syringe container. Glass syringes showed less intratube pressure and a stable injection rate, leading to more favorable results than nylon syringes. Further, intratube pressure was reduced by replacing the "winged-type" steel needle (21 G) with a "surflow-type" nylon needle (22 G) having the same internal diameter at the injection rate of 3 ml/sec. |
