Table 4.

Differences in mean FA values from C1/2 through C7/T1 for all subjects between observers 3 and 4.

Measurement method	Observer 3*	Observer 4†	P value
Mean ROI	0.617 ± 0.077‡	0.599 ± 0.072	0.015
Manual ROI	0.616 ± 0.080	0.597 ± 0.070	0.006
Sagittal ROI	0.549 ± 0.083	0.579 ± 0.074	0.020

*Third-year radiology resident (observer 3).

^†Neuro-radiologist with 2 years of experience in diffusion tensor imaging (observer 4).

^‡Mean FA value ± standard deviation.

FA, fractional anisotropy, ROI, region of interest.