Table 1

Accuracy and reliability of diameter measurements

Observer 1Observer 2Interobserver: observer 1 v observer 2
Conventional probeVAE probesConventional probeVAE probesConventional probeVAE probes
Performance orientationTrue diameter mean min–max (n=20)ICCDiffmean± SDD (± % SDD)ICCDiffmean± SDD (± % SDD)ICCDiffmean± SDD (± % SDD)ICCDiffmean± SDD (± % SDD)ICCDiffmean± SDD (± % SDD)ICCDiffmean± SDD (± % SDD)
VAE probe, variable angulated elongated probe (see text); accuracy, observed diameter minus true diameter; intraobserver reliability, agreement between 1st versus 2nd sets of estimates by each observer; interobserver reliability, agreement between the 1st sets of estimates by each observer; orientation, orientation of probe in relation to lesion (see fig 1); ICC, intraclass correlation coefficient (2.1) for agreement between observed diameter and true diameter (accuracy) and between repeated measurements; diffmean, mean of the difference scores (observed diameter minus true diameter); SDD, ± 1.96 standard deviations of the difference scores; (% SDD), SDD expressed as a percentage of maximum lesion size ((SDD/max diameter) × 100).
Accuracy
    Parallel8 (5–17)0.8203 (18)0.9302 (12)0.14−45 (29)0.66−14 (24)
    Orthogonal14 (4–36)0.9315 (14)0.9604 (11)0.59−66 (17)0.93−24 (11)
Reliability
    Parallel8 (5–17)0.7703 (18)0.9202 (12)0.6302 (12)0.7104 (24)0.18−44 (24)0.5805 (29)
    Orthogonal14 (4–36)0.9505 (14)0.9813 (8)0.9404 (11)0.9604 (11)0.54−86 (17)0.9524 (11)