Fig. 4
An ordinal logistic regression showed a significant correlation between the contrast ratio (CR) and the chosen image quality (IQ) of CACTMC_no_bone. This is reflected by the higher probability of choosing a better IQ with increasing contrast ratio and an odds ratio of 0.7 ± 1.1 (mean ± std. error). For CACTOrg, no significant correlation was noted between the CR and the readers’ evaluation of IQ, which is also demonstrated by the comparable probabilities of choosing IQ and an odds ratio of 1 ± 1 (mean ± std error). The gray area between the perforated and continuous line represents the 95% confidence interval