The improvement in the cerebral blood flow analysis software in case of CT-perfusion inspection and the examination of the scan protocol]

In our hospital, CT-perfusion was introduced in April, 2002. It is used to diagnose, to determine what treatment to use and to prognosticate cerebral blood flow after operation in super acute period brain infarct. At the beginning of the introduction, processing time and dosage for partial areas needed improvement. Therefore, we investigated the possibility of shorter processing time and lower dosage of radiation with the help of improvement in the analysis software as well as a different scan method. Two methods of reducing radiation dosage were examined. (1) The speed of X-ray rotation was slowed down; while photon per image was maintained, total mAs was lowered. (2) Continuation scan was replaced by intermission one. Analyzing time with older and newer version of analysis software was compared. The dosage was able to decrease by 25% as a result of the rotation speed slowed down; it became further less by 50% with the intermission scan. Processing such as the vein extraction was automated by using new analysis software and successfully shorten the analysing time without damaging the reliability of analyses. We forecast that more clinical research on further lowering dosage and stabilization of analyzing will enable us to provide better information.