Comparative Study: Ultrasound Imaging Texture Analysis vs. Force and Pressure Device for Regional Anaesthesia

Ultrasound is the standard for needle guidance in regional anaesthesia, enabling operations on awake patients with precise needle tip placement crucial for optimal outcomes. However, ultrasound has technical limitations that affect needle tip positioning. This study explores the effectiveness of 20 g short-bevelled block and 18 g Tuohy needles and infusion rates of 20 ml. min^-1 and 30 ml. min^-1 during fascial plane blocks on strain and B-mode imaging. Using texture analysis and a robotic device to evaluate needle force and pressure, the study analyzed six Thiel-embalmed cadavers, measuring needle insertion force and injection pressure during a 5 ml fluid injection. Using optical flow to identify moving pixels and calculate fluid spread within the region of interest (ROI)and Gray-Level Co-occurrence Matrix assessed contrast, homogeneity, and mean grey level (Intensity) of ROI. Statistical analysis via multivariate SPSS tests and MATLAB regression revealed significant impacts of needle gauge and infusion rate on imaging outcomes. The result showed that needle size significantly affected B-mode image area (p=0.01), contrast (p=0.03), and intensity (p < 0.03), as well as needle force (p < 0.001) and pressure (p < 0.001). Infusion rate significantly affected strain image homogeneity (p=0.04) but not B-mode features, needle force, or pressure. These findings highlight the importance of needle gauges in optimizing ultrasound-guided procedures and suggest that integrating these measurements with enhanced medical imaging can improve regional anaesthesia techniques.