Table 1.
Overall ICCs of FA measurements among the four observers.
| Level | Measurement method | Observer 1/2/3/4 (1st measurement) ICC(95% CI) |
Observer 1/2/3/4(2nd measurement) ICC(95% CI) |
|---|---|---|---|
| C1/2 | Mean ROI | 0.686 (0.543–0.808) | 0.460 (0.287–0.639) |
| Manual ROI | 0.572 (0.408–0.727) | 0.496 (0.324–0.668) | |
| Sagittal ROI | 0.500 (0.383–0.710) | 0.550 (0.383–0.710) | |
| C2/3 | Mean ROI | 0.716 (0.581–0.828) | 0.717 (0.583–0.829) |
| Manual ROI | 0.783 (0.670–0.872) | 0.679 (0.535–0.803) | |
| Sagittal ROI | 0.389 (0.216–0.579) | 0.374 (0.201–0.565) | |
| C3/4 | Mean ROI | 0.797 (0.690–0.881) | 0.732 (0.602–0.839) |
| Manual ROI | 0.808 (0.705–0.888) | 0.819 (0.720–0.894) | |
| Sagittal ROI | 0.700 (0.562–0.818) | 0.704 (0.566–0.820) | |
| C4/5 | Mean ROI | 0.800 (0.693–0.883) | 0.821 (0.723–0.896) |
| Manual ROI | 0.793 (0.684–0.879) | 0.784 (0.671–0.873) | |
| Sagittal ROI | 0.628 (0.473–0.767) | 0.594 (0.433–0.743) | |
| C5/6 | Mean ROI | 0.722 (0.589–0.832) | 0.574 (0.411–0.728) |
| Manual ROI | 0.616 (0.459–0.759) | 0.615 (0.457–0.758) | |
| Sagittal ROI | 0.432 (0.259–0.616) | 0.398 (0.224–0.586) | |
| C6/7 | Mean ROI | 0.538 (0.370–0.701) | 0.652 (0.502–0.785) |
| Manual ROI | 0.529 (0.360–0.694) | 0.536 (0.367–0.699) | |
| Sagittal ROI | 0.548 (0.381–0.709) | 0.553 (0.386–0.712) | |
| C7/T1 | Mean ROI | 0.726 (0.595–0.835) | 0.657 (0.508–0.788) |
| Manual ROI | 0.650 (0.500–0.783) | 0.618 (0.461–0.760) | |
| Sagittal ROI | 0.430 (0.256–0.613) | 0.404 (0.230–0.592) |
Two elective medical university students (observers 1 and 2), one third-year radiology resident (observer 3), and one neuro-radiologist with 2 years of experience in diffusion tensor imaging (observer 4).
FA, fractional anisotropy, ICC, intraclass correlation coefficient, CI, confidence interval, ROI, region of interest.