Statistical analysis
multiple lesions, CM
The sample size was determined based on a retrospective study examining improved image quality in monoenergetic images with reduced CM (4.3 ± 0.6 in monoenergetic images vs. 3.6 ± 0.3 in standard images) [The independent-samples To compare the detection rate of FLLs between groups, we estimated the reader-averaged figure of merit (FOM) using the random reader, random lesion method in a weighted free response receiver operating characteristic analysis. This considered multiple lesions and lesion locations within the same participant. FLLs were considered to have been detected by each reviewer if the lesion conspicuity score was 2 or higher. Lesion conspicuity and detection were evaluated for all participants and in subgroups stratified by FLL size (less than 20 mm vs. 20 mm or greater).All statistical analyses were conducted using commercially available software packages (SAS version 9.4, SAS Institute Inc., Cary, NC, USA; SPSS version 27, IBM Corp., Armonk, NY, USA; MedCalc version 20.216, MedCalc Software, Ostend, Belgium) and R version 4.1.1 (R Foundation for Statistical Computing, Vienna, Austria). A p-value of less than 0.05 was considered to indicate a statistically significant difference.