Statistics
The relationship of CT hardware parameters (CTW(n) and CTW(s)) with CTDI and SNR was
assessed using Pearson correlations for all three groups. The differences of characteristics as
well as CTDI and SNR among the three groups were tested by ANOVA with Bonferroni adjustment
for continuous variables and chi-square for categorical variables. Subgroup analysis comparing
helical and axial scanning modes were performed between Group B and C using t-tests.
All statistical analyses were performed using MedCalc (Version 13.2.2, MedCalc Software, Ostend,
Belgium).