RT Journal Article SR Electronic T1 Ultrasound for diagnosis of carpal tunnel syndrome: comparison of different methods to determine median nerve volume and value of power Doppler sonography JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 1934 OP 1939 DO 10.1136/annrheumdis-2012-202328 VO 72 IS 12 A1 Christian Dejaco A1 Martin Stradner A1 Dorothea Zauner A1 Werner Seel A1 Nicole Elisabeth Simmet A1 Alexander Klammer A1 Petra Heitzer A1 Kerstin Brickmann A1 Judith Gretler A1 Florentine C Fürst-Moazedi A1 Rene Thonhofer A1 Rusmir Husic A1 Josef Hermann A1 Winfried B Graninger A1 Stefan Quasthoff YR 2013 UL http://ard.bmj.com/content/72/12/1934.abstract AB Objective To compare ultrasound measurement of median nerve cross-sectional area (CSA) at different anatomical landmarks and to assess the value of power Doppler signals within the median nerve for diagnosis of carpal tunnel syndrome (CTS). Methods A prospective study of 135 consecutive patients with suspected CTS undergoing two visits within 3 months. A final diagnosis of CTS was established by clinical and electrophysiological findings. CSA was sonographically measured at five different levels at forearm and wrist; and CSA wrist to forearm ratios or differences were calculated. Intraneural power Doppler signals were semiquantitatively graded. Diagnostic values of different ultrasound methods were compared by receiver operating characteristic curves using SPSS. Results CTS was diagnosed in 111 (45.5%) wrists; 84 (34.4%) had no CTS and 49 (20.1%) were possible CTS cases. Diagnostic values were comparable for all sonographic methods to determine median nerve swelling, with area under the curves ranging from 0.75 to 0.85. Thresholds of 9.8 and 13.8 mm2 for the largest CSA of the median nerve yielded a sensitivity of 92% and a specificity of 92%. A power Doppler score of 2 or greater had a specificity of 90% for the diagnosis of CTS. Sonographic median nerve volumetry revealed a good reliability with an intraclass correlation coefficient of 0.90 (95% CI 0.79 to 0.95). Conclusions Sonographic assessment of median nerve swelling and vascularity allows for a reliable diagnosis of CTS. Determination of CSA at its maximal shape offers an easily reproducible tool for CTS classification in daily clinical practice.