Exploring the Biomechanical Blueprint: Precision Assessment and Standardization of 2D Shear‐Wave Elastography in Diabetic Peripheral Neuropathy

I read with great interest the article by Li et al, titled “Value of 2-Dimensional Shear-Wave Elastography in Assessing Tibial Nerve Stiffness in Diabetic Peripheral Neuropathy.”1 The authors present compelling evidence demonstrating that 2D shear-wave elastography (2D-SWE) can quantitatively differentiate the stiffness of the tibial nerve at various stages of diabetic peripheral neuropathy (DPN), including in asymptomatic patients. This represents an important step toward non-invasive early diagnosis. As a medical scientist focused on neurobiomechanics, I would like to raise several considerations to further enhance the standardization and clinical applicability of this promising technology. One key factor in nerve elastography is the physiological tension of the nerve trunk. The stiffness of the tibial nerve is highly sensitive to ankle joint kinematics. Studies have shown that, as the dorsiflexion angle of the ankle increases, the axial tensile stress increases non-linearly, which significantly elevates the shear wave velocity (SWV). To ensure that the measured stiffness reflects intrinsic pathological changes rather than physiological tension, measurements should ideally be taken when the ankle joint is in a neutral position or in a mild plantar flexion (typically less than 50% of the dorsiflexion range).2 Future protocols should define standardized joint angles to prevent “false positive” high stiffness readings caused by limb positioning.3 Although 2D-SWE is considered objective, the “pre-compression” of the ultrasound probe remains a major source of bias in the measurement of superficial structures such as the tibial nerve. Excessive pressure can artificially compress the tissue, leading to overestimation of the elastic modulus.4 To achieve “zero-pressure” imaging, it is recommended to use a thick layer of acoustic coupling gel or a “cushion” to ensure that the probe makes only light contact with the skin. Given that DPN patients may exhibit altered soft tissue compliance, this technical rigor is crucial for distinguishing nerve-specific fibrosis from changes in surrounding tissues. The diagnostic cutoff for distal stiffness reported by Li et al is 28.41 kPa, which is significantly lower than the threshold of over 70 kPa recorded in some international cohort studies. This discrepancy may stem from differences in the depth of the region of interest (ROI), manufacturer-specific algorithms, and the severity of DPN in the study populations.5 Such heterogeneity underscores the urgent need for multicenter studies to establish standardized, manufacturer-independent reference ranges before 2D-SWE is widely included in global clinical guidelines. Beyond cross-sectional diagnosis, the true value of 2D-SWE may lie in its ability to monitor treatment responses.6 Future studies should explore whether improvements in glycemic control or neurotrophic therapies are associated with reductions in nerve stiffness. Furthermore, combining elastography with high-resolution B-mode ultrasound features and microvascular blood flow imaging could lead to the development of a “multidimensional nerve health index” to guide personalized management. In conclusion, the research by Li et al represents a milestone in the application of biomechanical imaging to the field of DPN. With improved measurement protocols and resolution of technical confounding factors, 2D-SWE holds the potential to become a cornerstone of routine diabetes care, enabling interventions during the reversible stages of neuropathy. Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.