TABLE 3.
Agreement between FRAPPE and human reviewers in the Testing Set 1
| Variable | Reader |
Difference between FRAPPE and human reviewers |
||||||
|---|---|---|---|---|---|---|---|---|
| FRAPPE | Human | Mean | (95% CI) | CV | (95% CI) | ICC | (95% CI) | |
| Image-based measurements (n = 1391) | ||||||||
| Mean wall thickness, mm | 0.81 ± 0.16 | 0.76 ± 0.21 | 0.05 | (0.02, 0.08) | 12.3% | (9.4, 15.3) | 0.74 | (0.65, 0.79) |
| Max wall thickness, mm | 0.99 ± 0.38 | 0.96 ± 0.49 | 0.03 | (−0.03, 0.07) | 17.8% | (13.2, 22.2) | 0.84 | (0.77, 0.90) |
| Eccentricity ratio | 1.43 ± 0.51 | 1.59 ± 0.74 | −0.16 | (−0.24, −0.07) | 22.6% | (17.9, 26.8) | 0.72 | (0.55, 0.80) |
| Wall area, mm2 | 18 ± 6 | 17 ± 7 | 1.2 | (0.2, 1.9) | 14.5% | (10.3, 18.2) | 0.87 | (0.83, 0.89) |
| Lumen area, mm2 | 30 ± 12 | 30 ± 13 | −0.1 | (−0.6, 0.4) | 5.0% | (3.5, 6.8) | 0.99 | (0.98, 0.99) |
| Total vessel area, mm2 | 48 ± 17 | 47 ± 18 | 1.1 | (0.4, 1.7) | 4.7% | (3.3, 6.6) | 0.98 | (0.97, 0.99) |
| Normalized wall index, % | 38 ± 5 | 36 ± 6 | 1.9 | (0.6, 2.8) | 8.3% | (7.1, 9.6) | 0.71 | (0.60, 0.78) |
| Artery-based measurements (n = 25) | ||||||||
| Mean wall thickness, mm | 0.81 ± 0.10 | 0.75 ± 0.15 | 0.05 | (0.02, 0.09) | 8.7% | (6.4, 10.7) | 0.73 | (0.35, 0.89) |
| Max wall thickness, mm | 1.82 ± 0.73 | 1.83 ± 1.00 | −0.01 | (−0.25, 0.24) | 22.4% | (13.6, 32.3) | 0.78 | (0.56, 0.90) |
| Mean eccentricity ratio | 1.43 ± 0.21 | 1.59 ± 0.36 | −0.16 | (−0.24, −0.07) | 11.8% | (8.4, 14.5) | 0.68 | (0.22, 0.87) |
| Mean wall area, mm2 | 18 ± 5 | 16 ± 6 | 1.2 | (0.4, 2.1) | 10.0% | (7.1, 12.4) | 0.90 | (0.73, 0.96) |
| Mean lumen area, mm2 | 30 ± 11 | 30 ± 11 | −0.1 | (−0.7, 0.4) | 2.9% | (1.8, 4.1) | 0.99 | (0.99, 1.00) |
| Mean total vessel area, mm2 | 48 ± 16 | 46 ± 17 | 1.1 | (0.4, 1.7) | 2.8% | (2.0, 3.9) | 0.99 | (0.97, 1.00) |
| Mean normalized wall index, % | 38 ± 3 | 36 ± 5 | 1.9 | (0.8, 3.0) | 6.2% | (4.8, 7.5) | 0.70 | (0.30, 0.88) |
| Max normalized wall index, % | 46 ± 8 | 46 ± 10 | 0.1 | (−1.7, 1.9) | 6.5% | (3.9, 9.1) | 0.88 | (0.75, 0.95) |
Abbreviations: CV, coefficient of variation; FRAPPE, fully automated and robust analysis technique for popliteal artery evaluation; ICC, intraclass correlation coefficient.