Fig. 1. Transverse sonogram of the median nerve at three different levels in a normal subject. The cross-sectional area of the median nerve (oval dotted line). Flattening ratio was obtained by measuring transverse (a) and anteroposterior (b) diameters. (A) Hamate bone (H) level. (B) Pisiform bone (P) level. (C) Lunate bone (L) level.
