2004 Volume 60 Issue 3 Pages 423-428
In three-dimensional CT angiography (3DCTA) studies, we make it a rule to use a CT number monitoring system (SureStart, Toshiba Medical Systems Company) to ensure that contrast-enhanced images are acquired at the optimal timing. However, although SureStart can accurately determine enhancement start timing, it is still possible to inject more contrast medium than necessary because the scan start time is not known with certainty. To address this problem, we conducted investigations to determine the ideal contrast examination technique using SureStart and an injector synchronization system. Our results showed that a CT number of 300 HU in the middle cerebral artery (M1) could be obtained with the injection of contrast medium for a period of 45 s (450 mgI/kg)for the head or for 50 s (450 mgI/kg)for the craniocervical region. This makes it possible to perform contrast studies with greater reproducibility by taking individual variation into consideration. Moreover, it was found that comparable results could be obtained by terminating the injection of contrast medium 15s before the completion of the study and immediately injecting a physiological saline solution flush, permitting the volume of contrast medium to be further reduced.
