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Table 2 Intra-rater measures agreement results

From: A method for quantitative measurement of lumbar intervertebral disc structures: an intra- and inter-rater agreement and reliability study

Measurement n (slices) Mean (mm) Standard deviation (mm) Mean difference (bias) [95% CI] (mm) 95% LOA (mm) LOA as proportion of mean values (%)
Length - AIVH 258 14.7 1.1 0.2 [0.0; 0.3] −2.0; 2.3 29.3
Length - PIVH 258 9.5 0.8 0.1 [0.0; 0.2] −1.5; 1.6 32.6
Length - IVDL 258 31.1 0.5 −0.1 [−0.1; 0.0] −1.1; 1.0 6.8
Length - ADML 258 3.5 0.6 0 [−0.1; 0.1] −1.1; 1,1 62.9
Length - PDML 258 3.6 0.5 0 [−0.1; 0.1] −1.0; 1.0 55.6
Length - ADSL 227 8.5 0.8 −0.1 [−0.2; 0.0] −1.6; 1.4 35.3
  n (participants) (mm2) (mm2) (mm2) (mm2) (%)
Area - CAIH 24 512.6 19.1 6.2 [−1.8; 14.3] −31.2; 43.7 14.6
Area - CPIH 24 327.6 11.7 4.5 [−0.4; 9.4] −18.4; 27.4 14.0
Area - CIVD 24 1101.3 10.2 −1.2 [−5.5; 3.1] −21.3; 18.8 3.6
Area - CADM 24 118.8 10.2 1 [−3.3; 5.3] −19.0; 21.1 33.8
Area - CPDM 24 121.8 12.5 −1.6 [−6.9; 3.7] −26.0; 22.8 40.1
Area - CDS 25 267.9 18.6 −3.8 [−11.5; 3.9] −40.3; 32.7 27.2
   (mm3) (mm3) (mm3) (mm3) (%)
Volume - VADM 24 2136.7 246 −100 [−204; 4] −582; 382 45.1
Volume - VPDM 24 1314.8 126 −47 [−100; 6] −293; 199 37.4
  1. Number of slices measured for length, and participants measured for cross-sectional area and volume measurements, overall mean values, standard deviation, mean difference between measurements with 95% confidence intervals (CI), 95% limits of agreement (LOA), and LOA as a proportion of mean values. Due to absence of dural sac at certain otherwise measured slices, a lower number of slices were measured. Participants with unequal start- and end-slices were excluded from the analyses, leading to varying numbers of included participants.