The Added Value of High Frequency Ultrasound and Shear Wave Elastography in Diagnosis and Assessment of Carpal Tunnel Syndrome

Background: The most prevalent peripheral nerve entrapment condition is carpal tunnel syndrome (CTS). The median nerve is believed to be compressed as a result of elevated pressure inside the confined carpal tunnel. Although it might be subsequent to flexor tenosynovitis, ganglion cyst, gouty tophi, bone deformity, arthritis, or malignancy, increased carpal tunnel pressure is typically the underlying cause. The pathophysiology of CTS can be examined by evaluating the elasticity of the tissues within the carpal tunnel using sonoelastography. This imaging technique primarily involves SWE. Objective: To evaluate role of ultrasonography (B-mode and elastography) in diagnosis and assessment of CTS. To prove that ultrasound was a promising imaging tool in diagnosis of CTS alternative to traditional nerve conduction study. Patients and Methods: This study included 65 patients (40 cases and 25 controls) referred from the neurology and neurosurgery departments at Mansoura University Hospital followed by clinical examination and radiological diagnosis of CTS during the period from November 2023 to March 2025.
Results: Sonoelastography parameters were capable of diagnosing CTS with varying degrees of accuracy, with shear wave elastography being particularly accurate.  We recommended 55.95 kPa for shear wave elastography in the diagnosis of CTS, which resulted in 98% sensitivity and specificity.  A cut-off value of 13.5 mm CSA of the median nerve at proximal CTS yielded 96% sensitivity and 92% specificity for detecting instances of CTS.
Conclusion: The combined use of B-mode ultrasound and shear wave elastography (SWE) offers several benefits: (I) Severity Grading: The combined parameter also shows promise in distinguishing various degrees of CTS severity. By evaluating both structural and mechanical changes in the median nerve, clinicians can better assess the extent of nerve damage. (II) Non-Invasive and Quantitative: SWE provides a non-invasive and quantitative assessment of tissue elasticity, which can be useful in monitoring disease progression and treatment response.