Assessment of Pediatric Spinal Cord Tension Using Ultrasound Tensography Through a Novel Transcutaneous Method

Introduction: Tethered cord syndrome (TCS) presents a significant diagnostic challenge due to its variable clinical manifestations. Although increased stretching in the spinal cord is considered the cause, there is no clinical tool that can quantify spinal cord tension. Recently, ultrasound tensography was used intraoperatively to quantify the decrease in spinal cord tension after vertebral column shortening surgery. In this study, we present the first non-invasive measurements of spinal cord tension in pediatric patients using a novel transcutaneous method.

Methods: Ultrasound tensography of the lumbosacral spine was conducted in four neurologically normal pediatric patients using the Canon Aplio i800. Ultrasound images of the spinal cord were obtained in 2D-SWE mode with a Canon i18LX5 transducer, which was held manually in the midline sagittal plane over this region. Three ultrasound acquisitions were collected per patient. A heat map of spinal cord tension was created based on shear wave propagation and displayed as shear wave velocity (SWV). The mean SWV through the spinal cord in each image acquisition was extracted using the built-in region of interest trace tool.

Results: The four patients were 8 months, 10 months, 20 months and 3 years old. The average SWV of the lumbosacral spinal cord was 1.48 ± 0.6 m/s for patient one, 1.32 ± 0.7 m/s for patient two and 1.57 ± 0.2 m/s for patient three. Moderate flexion and extension of the lumbosacral region of these patients did not noticeably alter the SWV values obtained. The spinal cord of patient four was difficult to visualize with ultrasound, resulting in no SWV values being obtained.

Conclusion : This study demonstrates the feasibility of non-invasive transcutaneous ultrasound tensography to measure spinal cord tension in pediatric patients, with a potential age limit of 3 years for this technique. Further research is needed to refine the methodology and establish normative values for SWV in young children. Gaining a better understanding of the mechanical properties of the spinal cord in both normal and pathologic situations can facilitate the clinical translation of this tool.