A comparative study of image quality and radiation dosage between iterative reconstruction algorithm oflow-dose scans and filtered back project routine-dose scans in hepatic enhanced CT
XU Shu, HOU Yang, GUO Qi-yong
Department of Radiology, Shengjing Hospital of China Medical University, Shenyang 110004, China
Abstract：Objective: To assess the ability of iDOSE(iDOSE, Philips) iterative reconstruction technique for low-dose hepatic enhanced CT. Materials and Methods: 200 patients with diagnosis of liver tumors were randomly divided into four groups(A, B, C, D). Patients in group A were scanned with routine-dose CT, reconstructed with filtered back projection(FBP). While patients in group B, C, D were scanned with 30%, 50% and 70% radiation dose reduction CT respectively, reconstructed with iDOSE reconstruction. Quantitative noise and contrast-to-noise(CNR) measurements were performed. Qualitative ranking of sharpness of tumors, contrast between tumors and normal liver tissue, noise, and image quality were graded(scale: 1(worse)-4(best)). Data was analyzed using completely randomized design analysis of variance and Kruskal Wallis test. Results: In the comparison of quantitative noise, the groups with iDOSE reconstruction were lower than group A(P<0.01). CNR of groups with iDOSE reconstruction were higher than group A(P<0.01). There was no significant difference among the four groups for tumor tissue contrast and qualitative noise score(P=0.09, P=0.74). There was no significant difference between group B and A, C and A for tumor sharpness and image quality scores. However, a significant difference in tumor sharpness and image quality scores was observed beween group D and group A(P<0.01). Conclusions: When the radiation dose of hepatic enhanced CT scan was reduced by 50%, images maintaining the diagnostic quality of routine dose CT or even better images could be acquired with iDOSE technique.
2013, Vol. 24 
