A Saline Test Injection Mode Improving the Safety of Using a Power Injector for CT

Background: Computedtomography (CT) with rapid injection of contrastmediumis important for the diagnosis of manydiseases. To obtain good diagnostic accuracy, a power injector is recommended and routinely used to achieve a consistent injection rate of contrast medium. Although rapid contrast injection improves diagnostic accuracy, it increases the risk of extravasation of contrast medium. Objectives: The aim of this study was to evaluate the extravasation rate of contrast medium using a power injector and determine if using a saline test injection mode can reduce the rate. Patients and Methods: The records of 10,310 computed tomography (CT) examinations with contrast administration by a dualsyringe power injector were retrospectively reviewed. Before contrast administration, the same volume of saline was injected with a higher injection rate than that for contrast medium and the protocol was defined as “saline test injection mode”. The incident reports of patients with extravasations were reviewed and the extravasation rate and prevention rate were calculated. Results: Extravasations occurred in 12 (0.12%) of 10310 patients, and follow-up information was available for all patients. Five (41.67%) of 12 extravasations occurred during the saline test injection period, and the CT examinations were completed after creation of a new venous access. Contrast medium extravasation occurred in only six (0.06%) patients. One of the patients with contrast medium extravasation developed compartment syndrome and required decompression surgery. Other cases with extravasation had only mild symptoms and improved within 5 days. Conclusion: The saline test injection mode may reduce the risk of contrast medium extravasation and improve the safety of using a power injector.