Abstract
CT and MR perfusion imaging are useful tools in evaluation of regional blood flow in acute ischemic stroke. However, quantitative results show fluctuations, because scan protocol and analysis method are not standardized. In addition, inadequate settings of scan parameters can induce unnecessary radiation exposure in CT perfusion. Therefore, standardization of scan protocol, analysis methods, and evaluation methods are needed.
It is important to standardize scan parameters, in order to assure safety of the patients. Standardization of scan parameters and analysis methods is also important to minimize variations of quantitative values. In order to evaluate the degree of ischemia correctly, defining a universal index for the ischemic lesion, such as DWI-PWI mismatch, is required.
In summary, the goal of the standardization is to assure the safety of patients, to ensure the reliability of results, and to establish universal evaluation methods. In Japan, standardization of perfusion imaging, as well as other stroke imaging, is being carried out by ASIST-Japan (Acute Stroke Imaging Standardization).