Fig. 5.

Magnetic resonance images before and after minimally invasive ultrasound-guided percutaneous carpal tunnel release surgery. Magnetic resonance imaging using axial T2-weighted fat saturation sequences at the level of the hook of hamate. A Pre-operative. The median nerve is compressed by the TCL. The median nerve crosses the line connecting the hook of hamate to the ridge of the trapezium (scored as intermediary position). B 3 months after procedure. Gap in the TCL (double arrow). The median nerve is below the line connecting the hook of hamate to the ridge of the trapezium (scored as more superficial). The median nerve became rounder and larger. The continuous line surrounds the cross-sectional area of the median nerve. The dotted line connects the hook of hamate to the ridge of the trapezium