Quantification of Nerve Viscosity Using Shear Wave Dispersion Imaging in Diabetic Rats: A Novel Technique for Evaluating Diabetic Neuropathy

Abstract

Objective Viscoelasticity is an essential feature of nerves, although little is known about their viscous properties. The discovery of shear wave dispersion (SWD) imaging has presented a new approach for the non-invasive evaluation of tissue viscosity. The present study investigated the feasibility of using SWD imaging to evaluate diabetic neuropathy using the sciatic nerve in a diabetic rat model. Materials and Methods This study included 11 diabetic rats in the diabetic group and 12 healthy rats in the control group. Bilateral sciatic nerves were evaluated 3 months after treatment with streptozotocin. We measured the nerve cross-sectional area (CSA), nerve stiffness using shear wave elastography (SWE), and nerve viscosity using SWD imaging. The motor nerve conduction velocity (MNCV) was also measured. These four indicators and the histology of the sciatic nerves were then compared between the two groups. The performance of CSA, SWE, and SWD imaging in distinguishing the two groups was assessed using receiver operating characteristic (ROC) analysis. Results Nerve CSA, stiffness, and viscosity in the diabetic group was significantly higher than those in the control group (all p < 0.05). The results also revealed a significantly lower MNCV in the diabetic group ( p = 0.005). Additionally, the density of myelinated fibers was significantly lower in the diabetic group ( p = 0.004). The average thickness of the myelin sheath was also lower in the diabetic group ( p = 0.012). The area under the ROC curve for distinguishing the diabetic neuropathy group from the control group was 0.876 for SWD imaging, which was significantly greater than 0.677 for CSA ( p = 0.030) and 0.705 for SWE ( p = 0.035). Conclusion Sciatic nerve viscosity measured using SWD imaging was significantly higher in diabetic rats. The viscosity measured using SWD imaging performed well in distinguishing the diabetic neuropathy group from the control group. Therefore, SWD imaging may be a promising method for the evaluation of diabetic neuropathy.

Ultrasonic visualization technique for anatomical and functional analyses of the sciatic nerve in rats

“…is consistent with previous clinical human ultrasound anatomical studies (Cartwright et al, 2008). Due to the difference in the developmental law of body weight between rats of different genders, the sciatic nerve CSA of male rats was larger than that of females with increasing age but slightly smaller than the results reported by Yun-xia et al ( 2013) and Liu et al (2022). This could be related to where the sciatic nerve was measured and the ages of the rats in different studies.…”

“…Nevertheless, there were still a few procedures that did not achieve complete functional blockade, which might be related to the low frequency of the ultrasonic probe used in the study or the lack of clear imaging. In the future, more high-frequency ultrasound probes that are specific for use in small animals will be used (Liu et al, 2022 ). In addition, how to further popularize this technique also deserves attention; we intend to recruit more researchers without ultrasound experience to analyze the learning curve and develop a unified, standardized, and simple protocol to assess the ease of application and generalizability of the ultrasound-guided peri-sciatic nerve injection technique in basic animal studies.…”

Electrodiagnostic Testing and Nerve Ultrasound of the Carpal Tunnel in Patients with Type 2 Diabetes

“…CSA measurements at the outlet had possibly shown other results. In addition, other promising ultrasound techniques were not used in this study—particularly, the evaluation of echogenicity, the intraneural blood flow using Doppler ultrasound [ 9 ], or ultrasound elastography—to assess changes in stiffness of the nerve [ 34 , 35 ]. These techniques may provide additional information for CTS diagnosis but need more clinical evaluation.…”

Quantitative analysis of contrast-enhanced ultrasonography in rat models of hepatic acute graft-versus-host disease

“…Identical imaging parameters were set for all rats, including a gain of 75, depth of about 2.0 cm, mechanical index of 0.06, a focus of 92%, a dynamic range of 60 dB and a frame rate of 10 frames per second, according to instructions recommended by current guidelines ( 20 ). Before the examination, all rats were fasted for more than 6 h and then anesthetized by intraperitoneal administration of ketamine (60 mg/mL) and xylazine (7.5 mg/mL) ( 21 ). The rat was placed in a supine position, and the abdomen was shaved to allow clear ultrasound imaging of the liver.…”