Table 4.
The comparisons of intra-subject consistency between BC measurements on longitudinal scan pairs with and without FOV extension. The scan-wise BC measurements were defined as the summation of BC areas measured on the cross-sectional slices at T5, T8, and T10. For NLST, the intra-subject pairs were formed by the possible combinations of two screens for each subject, categorized into 1-year-pair and 2-year-pair based on the years of trial the two scans were conducted. For VLSP, pairs with time distance between 0.5 and 1.5 years were categorized as 1-year-pair, while pairs with time distance between 1.5 and 2.5 years were categorized as 2-year-pair in consistency with NLST. The pairs are further categorized into different truncation severity levels defined as the maximum of scan-wise truncation severity levels of the two paired scans. Spearman’s rank correlation coefficients with 95% confidence interval are reported. Results on groups with too few cases (e.g., less than six pairs) are not included. As FOV extension is not needed for pairs without truncation, only results on raw images are displayed when it is possible. Statistical significance are evaluated by method of (Silver et al., 2004) for comparison between two non-overlapping dependent correlations. The tests are two-sided, with p-values reported. BC=Body Composition. FOV=Field-of-view. SAT=Subcutaneous Adipose Tissue.
| SAT Area (cm2) | Muscle Area (cm2) | ||||||
|---|---|---|---|---|---|---|---|
| Cohort | Group (no. of pairs) | Without Correction | FOV Extended | p-value | Without Correction | FOV Extended | p-value |
| VLSP | No Truncation | ||||||
| 1-year-pair (N=13) | 0.967 (0.845,1.000) | - | - | 0.918 (0.659,0.994) | - | - | |
| 2-year-pair (N=6) | 0.886 (0.200, 1.000) | - | - | 0.771 (0.000, 1.000) | - | - | |
| Trace Truncation | |||||||
| 1-year-pair (N=233) | 0.946 (0.923, 0.961) | 0.941 (0.915, 0.958) | <.001 | 0.940 (0.914, 0.958) | 0.946 (0.923, 0.961) | <.001 | |
| 2-year-pair (N=79) | 0.894 (0.809, 0.947) | 0.893 (0.803, 0.951) | .89 | 0.955 (0.921,0.971) | 0.943 (0.895, 0.965) | .69 | |
| Mild Truncation | |||||||
| 1-year-pair (N=181) | 0.929 (0.896, 0.949) | 0.933 (0.899, 0.954) | .64 | 0.936 (0.908, 0.956) | 0.946 (0.922, 0.963) | .001 | |
| 2-year-pair (N=72) | 0.886 (0.797, 0.941) | 0.890 (0.805,0.944) | .69 | 0.911 (0.814, 0.962) | 0.925 (0.860, 0.961) | .49 | |
| Moderate Truncation | |||||||
| 1-year-pair (N=69) | 0.810 (0.701,0.881) | 0.908 (0.840, 0.947) | <.001 | 0.865 (0.751,0.931) | 0.944 (0.901,0.964) | <.001 | |
| 2-year-pair (N=31) | 0.762 (0.502, 0.898) | 0.906 (0.749, 0.967) | <.001 | 0.849 (0.663, 0.945) | 0.904 (0.806, 0.944) | .50 | |
| Severe Truncation | |||||||
| 1-year-pair (N=9) | 0.400 (−0.381,0.890) | 0.617 (−0.242,1.000) | .02 | 0.850 (0.352,1.000) | 0.983 (0.817, 1.000) | .16 | |
| 2-year-pair (N=3) | - | - | - | - | - | - | |
| Overall | |||||||
| 1-year-pair (N=505) | 0.950 (0.937, 0.959) | 0.961 (0.949, 0.969) | <.001 | 0.930 (0.910, 0.946) | 0.952 (0.940, 0.961) | <.001 | |
| 2-year-pair (N=191) | 0.927 (0.895, 0.947) | 0.941 (0.915, 0.959) | <.001 | 0.927 (0.889, 0.953) | 0.938 (0.912, 0.957) | .42 | |
| NLST | No Truncation | ||||||
| 1-year-pair (N=4) | - | - | - | - | - | - | |
| 2-year-pair (N=1) | - | - | - | - | - | - | |
| Trace Truncation | |||||||
| 1-year-pair (N=207) | 0.952 (0.932, 0.965) | 0.946 (0.923, 0.960) | <.001 | 0.934 (0.897, 0.959) | 0.927 (0.880, 0.955) | .028 | |
| 2-year-pair (N=105) | 0.955 (0.920, 0.972) | 0.951 (0.914, 0.970) | <.001 | 0.934 (0.886, 0.962) | 0.937 (0.898, 0.958) | .84 | |
| Mild Truncation | |||||||
| 1-year-pair (N=645) | 0.936 (0.922, 0.949) | 0.936 (0.921,0.948) | .96 | 0.942 (0.930, 0.952) | 0.936 (0.922, 0.947) | .21 | |
| 2-year-pair (N=329) | 0.885 (0.849, 0.911) | 0.886 (0.852, 0.915) | .50 | 0.912 (0.885,0.933) | 0.909 (0.880, 0.932) | .76 | |
| Moderate Truncation | |||||||
| 1-year-pair (N=853) | 0.901 (0.877, 0.918) | 0.926 (0.903, 0.942) | <.001 | 0.943 (0.935, 0.950) | 0.952 (0.943, 0.959) | <.001 | |
| 2-year-pair (N=388) | 0.875 (0.836, 0.904) | 0.898 (0.859, 0.927) | .026 | 0.941 (0.928, 0.950) | 0.953 (0.942, 0.960) | <.001 | |
| Severe Truncation | |||||||
| 1-year-pair (N=372) | 0.797 (0.751,0.837) | 0.916 (0.892, 0.934) | <.001 | 0.861 (0.818, 0.891) | 0.919 (0.893,0.939) | <.001 | |
| 2-year-pair (N=206) | 0.782 (0.707, 0.841) | 0.894 (0.854, 0.921) | <.001 | 0.833 (0.775, 0.875) | 0.917 (0.877,0.942) | <.001 | |
| Overall | |||||||
| 1-year-pair (N=2,081) | 0.912 (0.901,0.922) | 0.950 (0.942, 0.957) | <.001 | 0.944 (0.938, 0.949) | 0.951 (0.946, 0.956) | <.001 | |
| 2-year-pair (N=1,029) | 0.880 (0.859, 0.898) | 0.925 (0.909, 0.938) | <.001 | 0.933 (0.924, 0.940) | 0.948 (0.940, 0.955) | <.001 | |