Table 5 Parameter for evaluation of carpal tunnel syndrome [18, 19]

CSA (mm²)

Continuous trace method

7.55 (1.58)

10.3 (2.3)

9.00 (1.98)

9.0 (2.5)

9.1 (2.3)

8.8 (1.8)

Flattening ratio

Transverse axis divided by longitudinal axis

2.2 (0.29)

2.27 (0.3)

2.96 (0.4)

2.38 (0.61)

2.62 (0.55)

2.76 (0.75)

Palmar displacement (mm) (measured on T1 image)

Perpendicular distance to the TCL from the line between the hook of the hamate and the trapezium

2.9

2.5

2.58 (0.82)

Swelling ratio

Middle CSA to proximal CSA

1.3