Room: ePoster Forums
Purpose: To explore the effect of ECG 4D-CT special reconstruction algorithm on cardiac structural dose assessment, and to find a simple image for evaluating cardiac structural dose-volume index.
Methods: ECG 4D-CT series were obtained from each patient, and 20 phases of 0% ~ 95% series were reconstructed at intervals of 5% cardiac cycle. The 4D-CT series were reconstructed specially, and the maximum, minimum, average and sum density projection were obtained. The left ventricular muscle (LV) and the left anterior descending branch of coronary artery (LAD) were delineated on 20 time phases and special reconstruction images, respectively. The plan was designed on the basis of 0% phase, and the cumulative dose Dose-20, of 20 phases was obtained by deformation registration. The dose-volume indicators difference of LV and LAD among different CT seires were compared.
Results: In the dose assessment of LV. The change rates of V5, V30, V40, Dmax and Dmean, of Dose-MIP were 3.8%, 2.0%, 0.9%, 3.8% and 1.7%, respectively, which were higher than those of Dose-20. The Dmax, change rates of Dose-MinIP, Dose-SIP and Dose-AIP were 2.5%, 3.1% and 1.5% respectively, and the Dmean, change rates of Dose-SIP were 3.8% (P<0.05). The change rates of other indexes >5%. In the dose assessment of LAD, only the change rate of Dmax in four special reconstructed images <5% (P<0.05).
Conclusion: The V5, V30, V40 and Dmean obtained from Dose-MIP were similar as Dose-20, so Dose-MIP could be used to evaluate the dose-volume index of LV.