title: Carpal tunnel: Normal anatomy, anatomical variants and ultrasound technique.
abstract: The carpal tunnel is an osteofibrous canal situated in the volar wrist. The boundaries are the carpal bones and the flexor retinaculum. In addition to the medial nerve, the carpal tunnel contains nine tendons: the flexor pollicis longus, the four flexor digitorum superficialis and the four flexor digitorum profundus. Ultrasound (US) study of the carpal tunnel generally involves short-axis imaging of the tendons, and in the presence of disease, long-axis imaging and dynamic maneuvers are added. There are numerous reports of anatomical variants of the wrist involving vessels, nerves, tendons and muscles, and they can all be studied by US. Some are particularly relevant from a clinical point of view and will therefore be accurately described. The anatomy is complex, and the US operator should therefore be thoroughly familiar with the normal anatomy as well as the anatomical variants that may have a role in the pathogenesis of carpal tunnel syndrome or influence treatment.
authors: Foundation IRCCS, Policlinico San Matteo, Institute of Radiology, University of Pavia, Italy.
authors: A
authors: A
authors: Presazzi
authors: C
authors: C
authors: Bortolotto
authors: M
authors: M
authors: Zacchino
authors: L
authors: L
authors: Madonia
authors: F
authors: F
authors: Draghi
keywords: Carpal tunnel; Flexor tendons; Median nerve; Ultrasound
references: Radiographics. 2000 Oct;20 Spec No:S199-213; discussion S213-7
references: 11046171
references: J Neurol Neurosurg Psychiatry. 1977 Oct;40(10):982-6
references: 201732
references: Radiographics. 2008 Mar-Apr;28(2):481-99
references: 18349452
references: Skeletal Radiol. 2010 Aug;39(8):733-45
references: 19722104
references: Can J Plast Surg. 2009 Fall;17(3):e3-7
references: 20808747
references: Radiographics. 2005 Nov-Dec;25(6):1577-90
references: 16284136
references: J Anat. 2006 Apr;208(4):527-42
references: 16637876