Reference Values of Shear Wave Elastography of Median and Tibial Nerve in Healthy Population: A Cross-sectional Study

Abstract

Introduction: Peripheral nerves are rarely assessed using high-resolution Ultrasonography (USG). Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scans can be costly and occasionally inaccessible. In contrast, USG provides a dynamic, portable and cost-effective method for evaluating peripheral nerves. Shear Wave Elastography (SWE) is a relatively recent ultrasound-based technique that quantitatively measures tissue stiffness. Aim: To determine the reference values for SWE measurements of the median and tibial nerves in healthy individuals and to explore potential associations with age, gender, height, weight and Body Mass Index (BMI) of the subjects. Materials and Methods: The present cross-sectional study was conducted in the Radiodiagnosis and Imaging Unit, Sri Guru Ram Das Institute of Medical Sciences and Research, Sri Amritsar, Punjab, India, from October 2022 to April 2024, involved 100 subjects (45 males and 55 females). Subjects were deemed eligible for the study following evaluation by a general physician. The study was conducted over a period of one year. High-resolution real-time USG was utilised to assess the median and tibial nerves in both arms and legs bilaterally. SWE was conducted on the tibial and median nerves, and the velocities generated were subsequently evaluated to establish baseline levels for the peripheral nerves. Collected data were transformed, coded and entered into Microsoft Excel, then analysed using Statistical Package for Social Sciences (SPSS) software version 25.0 (SPSS-PC-25). Parametric data were expressed as mean±Standard Deviation (SD) or median and compared using the Mann-Whitney U test. Results: The mean age of healthy subjects was 41.18±12.34 years, while the weight and height were 72.59±7.44 kg and 172.74±6.75 cm, respectively. The average velocities generated in healthy subjects (45 males and 55 females) using SWE were found to be 3.606±0.133 m/s and 3.632±0.173 m/s for the left and right median nerves (p-value >0.05), and 3.626±0.140 m/s and 3.623±0.138 m/s for the left and right tibial nerves (p-value>0.05), respectively. The SWE measurements obtained from the bilateral median and tibial nerves showed no significant differences in their values, indicating no significant association (p-value>0.05). No significant correlation was found between the SWE measurements and age, sex, height, weight, or BMI of the subjects (p-value>0.05). Conclusion: The present study serves as an initial step in gathering tibial nerve stiffness values from healthy participants using SWE and exploring the factors affecting nerve stiffness.

Keywords

• high-resolution ultrasound
• malleolus
• peripheral nerves
• velocities