Effects of Mathematical Analysis of Test Injection on the CT Value Estimation of the Aorta

The circulation time and the mechanical acceleration time (MA time) of an automatic injector were simulated using pharmacokinetic analysis. The addition method and transfer-function method, which are mathematical techniques used for analyzing the test bolus method in multi-detector computed tomography, were used to verify the accuracy of estimation of the time-enhancement curve (TEC) of the main bolus. The TEC estimated using the addition method, and the TEC of the main bolus matched completely only if the MA time of the automatic injector was set to 0 seconds. Moreover, the estimation accuracy of the TEC deteriorated when the MA time was set according to the TEC estimated by the addition method. In contrast, the TEC estimated using the transfer-function method, except when the MA time of the automatic injector was 0 seconds, had higher accuracy than the TEC estimated using the addition method. In this study, the addition method, a number of additions of TEC, and MA time of the automatic injector were found to have a negative effect on the estimation accuracy of the main bolus. The use of the transfer-function method for determining the TEC and the MA time has a positive effect on the estimation accuracy of the main bolus.