CT of carpal tunnel syndrome.

The carpal tunnel was investigated by high-resolution computed tomographic (CT) scanning of two cadavers, two healthy persons, and 20 patients with carpal tunnel syndrome to outline normal and pathologic anatomy. The following changes leading to median nerve compression in the carpal canal were demonstrated by CT: (1) thickening of the transverse carpal ligament with resultant decrease in the volume of the carpal tunnel, thus leading to compression of its contents; (2) synovial sheath "hypertrophy" of the flexor tendons, in which compression of the nerve seems to be caused by an increase in volume of the tissues within the carpal canal due to the thickened synovium around the flexor tendon; and (3) recurrent fibrosis after surgery.