A Protocol for Contrast Enhanced CT Using a Fixed Injection Period for the Contrast Agent

Abstract

The purpose of this paper was to make an appropriate protocol for obtaining desirable contrast effects by contrast enhanced computed tomography (CT) regardless of the size of animals in veterinary clinics. Using a total of 214 cats and dogs of various sizes, non-ionic iodine contrast agent was injected to each animal (600 mgI/2.0 ml/kg) for 5, 10, 15, 20, or 30 seconds at random. When the injection time was 10 seconds or less, scanning timing was too short because the time density curve had a narrow peak. When the injection period was 30 seconds, the time density curve was too broad. Consequently an appropriate injection time was considered to be 15 to 20 seconds. Our protocol will be useful in providing reproducible contrast effects in small animals.