Table 4. The univariate linear regression analysis of factors affecting DTI parameters.

DTI parameters	iFA	mFA	oFA	Delta FA	Delta MD
Symptom Boston score
Beta-coefficient	−0.04	−0.03	−0.04
P value	<0.001	<0.001	<0.001	0.835	0.595
95% CI (lower, upper)	−0.06, −0.03	−0.04, −0.02	−0.05, −0.02
Function Boston score
Beta-coefficient	−0.04	−0.03	−0.04
P value	<0.001	<0.001	<0.001	0.679	0.785
95% confidence interval (lower, upper)	−0.06, −0.02	−0.05, −0.02	−0.05, −0.02
Distal motor latency time
Beta-coefficient				−0.03	0.16
P value	0.142	0.644	0.662	<0.001	<0.001
95% confidence interval (lower, upper)				−0.04, −0.02	0.08, 0.23
iCSA
Beta-coefficient	−0.007	−0.005	−0.005
P value	<0.001	<0.001	<0.001	0.49	0.243
95% confidence interval (lower, upper)	−0.009, −0.004	−0.007, −0.003	−0.007, −0.003

DTI, diffusion tensor imaging; CI, confidence interval; d, i, m, and o, at the distal radioulnar joint, the inlet, the middle, the outlet of the carpal tunnel, respectively; FA, fractional anisotropy; Delta FA = oFA – dFA; Delta MD = oMD – dMD; CSA, cross-sectional area.