1186 settings on volume measurement was quantified by multi- level modelling and demonstrated that 1 mm section thickness and a sharp kernel led to larger volumes and that the effect was different for the different nodule types (Table 3). Therefore, consistency in the use of reconstruc- tion settings is recommended for follow-up CT. A limitation of our study is that we used only three reconstruction settings. Therefore, it is difficult to general- ise the conclusions on the effect of section thickness and kernel. We decided to choose these three particular settings because they are most commonly used in low-dose chest CT. Furthermore, the accuracy of segmentation was not visually evaluated. It should be mentioned that manual adjustment of segmented volume will influence the standardisation of volume measurement in large popula- tions and therefore was not applied in our study. Finally, the results of our study are only applicable for the specific software used. 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