Table 2.

Attenuation coefficient inter-platform reproducibility for measurements based on a single acquisition (N=1) and on the mean of multiple repeated intra-platform acquisitions (N=2, 3, 4, and 5).

Number of acquisitions N	GE mean ± SD (dB/cm-MHz)	Siemens mean ± SD (dB/cm-MHz)	ICC (95% CI)	wCV
1	0.89 ± 0.13	0.94 ± 0.15	0.69 (0.50, 0.81)	0.09
2	0.89 ± 0.13	0.94 ± 0.15	0.76 (0.58, 0.86)	0.08
3	0.89 ± 0.13	0.94 ± 0.15	0.75 (0.57, 0.86)	0.08
4	0.90 ± 0.13	0.94 ± 0.15	0.77 (0.58, 0.86)	0.07
5	0.90 ± 0.13	0.94 ± 0.15	0.77 (0.59, 0.87)	0.07

ICC was calculated based on a single-unit, absolute-agreement, two-way mixed effect analysis of variance (ANOVA) model.

CI confidence interval, ICC intraclass correlation coefficient, SD standard deviation, wCV within-subject coefficient of variation