Study: Ultrasound Accurately Diagnoses Carpal Tunnel
John R. Fowler, MD, from the University of Pittsburgh, and colleagues compared the sensitivity and specificity of ultrasound and electrodiagnostic testing for diagnosing carpal tunnel syndrome in a series of 85 patients. All patients were assessed with the Carpal Tunnel Syndrome 6 (CTS-6) clinical diagnostic tool, which was used as the reference standard.
The researchers found that ultrasound had a sensitivity of 89% and specificity of 90%, while electrodiagnostic testing had a sensitivity of 89% and specificity of 80%. The positive predictive values were 94 and 89%, respectively, for ultrasound and electrodiagnostic testing, while the negative predictive values were 82 and 80%, respectively. Ultrasound was accurate in 89% of cases and electrodiagnostic testing was accurate in 86% of cases.
"While ultrasound will not replace electrodiagnostic testing in complicated or unclear cases, in a select group of patients with a positive CTS-6, ultrasound can be used to confirm the diagnosis of carpal tunnel syndrome with better specificity and equal sensitivity as compared with those of electrodiagnostic testing," the authors write.