Diagnostic performance of two-dimensional shear wave elastography for evaluating tibial nerve stiffness in patients with diabetic peripheral neuropathy

Using ultrasound shear wave elastography to characterize peripheral nerve mechanics: a systematic review on the normative reference values in healthy individuals

Ultrasound shear wave elastography (SWE) is an emerging non-invasive imaging technique for peripheral nerve evaluation. Shear wave velocity (SWV), a surrogate measure of stiffness, holds promise as a biomarker for various peripheral nerve disorders. However, to maximize its clinical and biomechanical value, it is important to fully understand the factors that influence nerve SWV measurements. This systematic review aimed to identify the normal range of SWV for healthy sciatic and tibial nerves and to reveal the factors potentially affecting nerve SWV. An electronic search yielded 17 studies eligible for inclusion, involving 548 healthy individuals (age range, 17 to 72 years). Despite very good reliability metrics, the reported SWV values differed considerably across studies for the sciatic (1.9-9.9 m/s) and tibial (2.3-9.1 m/s) nerves. Factors such as measurement proximity to joint regions, limb postures inducing nerve axial stretching, and transducer alignment with nerve fiber orientation were associated with increased SWV. These findings suggest regional-specific nerve mechanical properties, non-linear elastic behaviour, and marked mechanical anisotropy. The impact of age and sex remains unclear and warrants further investigation. These results emphasize the importance of considering these factors when assessing and interpreting nerve SWE. While increased SWV has been linked to pathological changes affecting nerve tissue mechanics, the significant variability observed in healthy nerves highlights the need for standardized SWE assessment protocols. Developing guidelines for enhanced clinical utility and achieving a comprehensive understanding of the factors that influence nerve SWE assessments are critical in advancing the field.

Longitudinal Movements and Stiffness of Lower Extremity Nerves Measured by Ultrasonography and Ultrasound Elastography in Symptomatic and Asymptomatic Populations: A Systematic Review With Meta-analysis

This study was aimed at analyzing the effectiveness of ultrasonography (US) and ultrasound elastography (UE) in evaluating longitudinal sliding and stiffness of nerves. In line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, we analyzed 1112 publications (range: 2010-2021) extracted from MEDLINE, Scopus and Web of Science focusing on specific outcomes, including shear wave velocity (m/s), shear modulus (kPa), strain ratio (SR) and excursion (mm). Thirty-three papers were included and evaluated for overall quality and risk of bias. From the analysis of data concerning 1435 participants, mean shear wave velocity (SWV) in the sciatic nerve was 6.70 ± 1.26 m/s in controls and 7.51 ± 1.73 m/s in participants presenting with leg pain; in the tibial nerve, mean SWV was 3.83 ± 0.33 m/s in controls and 3.42 ± 3.53 m/s in participants presenting with diabetic peripheral neuropathy (DPN). The mean shear modulus (SM) was 20.9 ± 9.33 kPa for sciatic nerve, whereas it was an average of 23.3 ± 7.20 kPa for the tibial nerve. Considering 146 subjects (78 experimental, 68 controls) no significant difference was observed in SWV when comparing participants with DPN with controls (standard mean difference [SMD]: 1.26, 95% confidence interval [CI]: 0.54, 1.97), whereas a significant difference was observed in the SM (SMD: 1.78, 95% CI: 1.32, 2.25); furthermore, we found significant differences between left and right extremity nerves (SMD:1.14. 95% CI: 0.45, 1.83) among 458 participants (270 with DPN and 188 controls). No descriptive statistics are available for excursion because of the variability in participants and limb positions, whereas SR is considered only a semiquantitative outcome and therefore not comparable among different studies. Despite the presence of some limitations in study designs and methodological biases, on the basis of our findings, we can conclude that US and UE are effective methods in assessing longitudinal sliding and stiffness of lower extremity nerves in both symptomatic and asymptomatic subjects.

Quantitative Ultrasound Techniques Used for Peripheral Nerve Assessment

AIM

This review article describes quantitative ultrasound (QUS) techniques and summarizes their strengths and limitations when applied to peripheral nerves.

METHODS

A systematic review was conducted on publications after 1990 in Google Scholar, Scopus, and PubMed databases. The search terms "peripheral nerve", "quantitative ultrasound", and "elastography ultrasound" were used to identify studies related to this investigation.

RESULTS

Based on this literature review, QUS investigations performed on peripheral nerves can be categorized into three main groups: (1) B-mode echogenicity measurements, which are affected by a variety of post-processing algorithms applied during image formation and in subsequent B-mode images; (2) ultrasound (US) elastography, which examines tissue stiffness or elasticity through modalities such as strain ultrasonography or shear wave elastography (SWE). With strain ultrasonography, induced tissue strain, caused by internal or external compression stimuli that distort the tissue, is measured by tracking detectable speckles in the B-mode images. In SWE, the propagation speed of shear waves, generated by externally applied mechanical vibrations or internal US "push pulse" stimuli, is measured to estimate tissue elasticity; (3) the characterization of raw backscattered ultrasound radiofrequency (RF) signals, which provide fundamental ultrasonic tissue parameters, such as the acoustic attenuation and backscattered coefficients, that reflect tissue composition and microstructural properties.

CONCLUSIONS

QUS techniques allow the objective evaluation of peripheral nerves and reduce operator- or system-associated biases that can influence qualitative B-mode imaging. The application of QUS techniques to peripheral nerves, including their strengths and limitations, were described and discussed in this review to enhance clinical translation.

Effect of Surgical Release of Entrapped Peripheral Nerves in Sensorimotor Diabetic Neuropathy on Pain and Sensory Dysfunction-Study Protocol of a Prospective, Controlled Clinical Trial

BACKGROUND

Nerve entrapment has been hypothesized to contribute to the multicausal etiology of axonopathy in sensorimotor diabetic neuropathy. Targeted surgical decompression reduces external strain on the affected nerve and, therefore, may alleviate symptoms, including pain and sensory dysfunction. However, its therapeutic value in this cohort remains unclear.

AIM

Quantifying the treatment effect of targeted lower extremity nerve decompression in patients with preexisting painful sensorimotor diabetic neuropathy and nerve entrapment on pain intensity, sensory function, motor function, and neural signal conduction.

STUDY DESIGN

This prospective, controlled trial studies 40 patients suffering from bilateral therapy-refractory, painful (n = 20, visual analogue scale, VAS ≥ 5) or painless (n = 20, VAS = 0) sensorimotor diabetic neuropathy with clinical and/or radiologic signs of focal lower extremity nerve compression who underwent unilateral surgical nerve decompression of the common peroneal and the tibial nerve. Tissue biopsies will be analyzed to explore perineural tissue remodeling in correlation with intraoperatively measured nerve compression pressure. Effect size on symptoms including pain intensity, light touch threshold, static and moving two-point discrimination, target muscle force, and nerve conduction velocity will be quantified 3, 6, and 12 months postoperatively, and compared (1) to the preoperative values and (2) to the contralateral lower extremity that continues non-operative management.

CLINICAL SIGNIFICANCE

Targeted surgical release may alleviate mechanical strain on entrapped lower extremity nerves and thereby potentially improve pain and sensory dysfunction in a subset of patients suffering from diabetic neuropathy. This trial aims to shed light on these patients that potentially benefit from screening for lower extremity nerve entrapment, as typical symptoms of entrapment might be erroneously attributed to neuropathy only, thereby preventing adequate treatment.

Evaluation of Sciatic Nerve Stiffness Using Shear Wave Elastography in Patients with Unilateral Diabetic Foot Ulcers

OBJECTIVE

To evaluate the stiffness of the sciatic nerve by shear wave elastography (SWE) and to determine whether SWE can be used to predict diabetic foot ulcer (DFU) in a patient with diabetic peripheral neuropathy (DPN).

METHODS

Sixteen patients (thirty-two lower limbs) with unilateral DFU were studied retrospectively. The ultrasonographic parameters including cross-sectional area (CSA) of sciatic nerve, intraneural blood flow, peak systolic velocity (Vmax) and resistive index (RI) in the intraneural artery of the sciatic nerve, and the SWE stiffness value of the sciatic nerve were measured. The examinations of arteries of the lower limbs were also performed by ultrasound. According to the presence or absence of DFU, the 32 lower limbs were divided into two groups: the DFU group and the non-DFU group. The ultrasonographic parameters were compared between these two groups.

RESULTS

There was no significant difference (p > 0.05) between the two groups for CSA, intraneural blood flow, Vmax and RI in the intraneural artery of the sciatic nerve, and numbers of severe artery stenosis or full occlusion of the artery in the lower limbs. However, SWE stiffness values in the sciatic nerve in the DFU group are higher than the non-DFU group (p < 0.05). When the SWE stiffness values were used for prediction of DFU in patients with DPN, the area under the ROC curve (AUC) was 0.727 (95% CI: 0.541-0.868). When the best SWE stiffness value of 24.48 kPa was taken as a cutoff for prediction of DFU, the sensitivity was 62.50% (95% CI: 35.4-84.8%), and the specificity was 75% (95% CI: 47.6-92.7%).

CONCLUSIONS

Sciatic nerve stiffness is significantly higher in lower limbs with DFU. SWE is a noninvasive imaging method that may be used to evaluate sciatic nerve stiffness, then potentially predict DFU in patients with DPN.

Evaluation of the clinical value of shear wave elastography for early detection and diagnosis of diabetic peripheral neuropathy: a controlled preliminary prospective clinical study

PURPOSE

This study aims to analyze the clinical application value of shear wave elastography (SWE) technique for early diagnosis of diabetic peripheral neuropathy (DPN).

METHODS

Diabetic patients hospitalized in the Department of Endocrinology of the First Affiliated Hospital of Anhui Medical University from August 2021 to February 2022 were enrolled as DPN group (n=38) and non-DPN group (n=35) based on the neurophysiological examination results. 30 healthy subjects were recruited as the control group during the same period. Ultrasound examination of the tibial nerve and related laboratory tests were examined and collected for the total 103 study subjects. Statistical analysis of the collected data, and the receiver operating characteristic(ROC) curve for determination of the optimal cut-off values of mean stiffness of tibial nerve to detect DPN, with determination of area under curve (AUC), specificity, sensitivity, and Youden index.P value < 0.05 is considered statistically significant.

RESULTS

Gender, age and BMI differences among three groups were insignificant (P>0.05). The difference of serological indicators between DPN and non-DPN groups was also not found (P>0.05), whereas longer duration of diabetes was observed in DPN group as compared to non-DPN group. As to the ultra-sound relevant parameters, the cross-sectional area and elastic modulus of the tibial nerve in both lower extremities among these three groups were not significantly different (Oneway ANOVA analysis) although the differences were indeed observed if we compared DPN group exclusively with non-DPN group, or compared non-DPN group with healthy group, or compared DPN group with healthy group (t test). Additionally, the mean elasticity (Emean) cut-off value for the diagnosis of DPN was preferably taken as 67.55 kPa.

CONCLUSION

SWE has unique advantages in early detection and diagnosis of DPN, which deserve further research.

Ultrasound and elastography role in pre- and post-operative evaluation of median neuropathy in patients with carpal tunnel syndrome

Introduction

Carpal tunnel syndrome (CTS) is a common compression neuropathy of the median nerve in the wrist. Early diagnosis of CTS is essential for selecting treatment options and assessing prognosis. The current diagnosis of CTS is based on the patient's clinical symptoms, signs, and an electromyography (EMG) test. However, they have some limitations. Recently, ultrasound has been adopted as an adjunct diagnostic tool for electromyography (EMG). Ultrasound is a non-invasive and cost-effective technique. It provides a dynamic display of morphological changes in the median nerve and an assessment of CTS etiology such as tenosynovitis, mass compression, and tendon disease. This study aimed to investigate the value of conventional ultrasound and real-time shear wave elastography (SWE) in evaluation of median neuropathy in patients with carpal tunnel syndrome (CTS) before and after surgery.

Methods

First, the Boston Carpal Tunnel Questionnaire (BCTQ) was administered to patients with CTS. All subjects were measured at three levels: the distal 1/3 of the forearm, the carpal tunnel inlet, and the distal carpal tunnel using conventional ultrasound and SWE. Median nerve parameters were examined in patients with CTS 1 week after surgery.

Results

The cross-sectional area (CSA) and stiffness of the median nerve at the carpal tunnel inlet and distal carpal tunnel were significantly higher in patients with CTS than in healthy controls (p < 0.001). The CSA and stiffness of the median nerve at the carpal tunnel inlet were statistically significantly significantly between pre- and postoperative patients with CTS (p < 0.001). The CSA and stiffness of the nerve in patients with CTS had a positive correlation with electrophysiology severity.

Conclusions and discussion

Conventional ultrasound and elastography are valuable in the diagnosis of CTS and are useful in the clinical assessment of patient's nerve recovery after operation.

Quantitative shear wave elastography assessment of tibial nerve in diagnosis of diabetic peripheral neuropathy

Background

Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes mellitus. Diagnosis of DPN is very important in the prognosis of disease and treatment as early treatment of DPN decreases both short-term and long-term morbidities. SWE elastography is a noninvasive and reproducible method for the precise evaluation of nerve stiffness.

Results

Tibial nerve stiffness is notably high at SWE in diabetic patients with DPN (mean shear wave elastography value of RT tibial SWE 75.3 ± 15.1 kPa) compared to patients without DPN (mean shear wave elastography value of RT tibial SWE 37.8 ± 11.6 kPa) and nerve stiffness in healthy control subjects (mean shear wave elastography value of RT tibial SWE 24.9 ± 6.3 kPa). There is a significant increase in the cross-sectional area (CSA) among diabetic patients with DPN (mean cross-sectional area of the right tibial nerve of 17 ± 1.9 mm2) and without DPN (mean cross-sectional area of the right tibial nerve of 14.5 ± 3.8 mm2) in comparison with control subjects (mean cross-sectional area of the right tibial nerve of 13.2 ± 3.1 mm2) in the right side. Borderline significance of the CSA parameters of the tibial nerve study on the left side in different groups. The cutoff point to determine DPN among diabetic patients in the right lower limb is more than 63.8 kPa. With 89% sensitivity and 100% specificity in the detection of DPN on the right side, the SWE has 100% PPV and 95.5% NPV in the detection of DPN on the right side.

Conclusion

SWE is an effective assistant method in the diagnosis of DPN and is useful when a suspected neuropathy is not detectable by electrophysiology.

Effects of Different Long-Term Exercise Modalities on Tissue Stiffness

Stiffness is a fundamental property of living tissues, which may be modified by pathologies or traumatic events but also by nutritional, pharmacological and exercise interventions. This review aimed to understand if specific forms of exercise are able to determine specific forms of tissue stiffness adaptations. A literature search was performed on PubMed, Scopus and Web of Science databases to identify manuscripts addressing adaptations of tissue stiffness as a consequence of long-term exercise. Muscular, connective, peripheral nerve and arterial stiffness were considered for the purpose of this review. Resistance training, aerobic training, plyometric training and stretching were retrieved as exercise modalities responsible for tissue stiffness adaptations. Differences were observed related to each specific modality. When exercise was applied to pathological cohorts (i.e. tendinopathy or hypertension), stiffness changed towards a physiological condition. Exercise interventions are able to determine tissue stiffness adaptations. These should be considered for specific exercise prescriptions. Future studies should concentrate on identifying the effects of exercise on the stiffness of specific tissues in a broader spectrum of pathological populations, in which a tendency for increased stiffness is observed.

Ultrasound exploration of muscle characteristic changes and diabetic peripheral neuropathy in diabetic patients

PURPOSE

Using brightness mode ultrasound combined with shear wave elastography, this study aims to detect structural and functional changes of the medial head of gastrocnemius (MG) in type 2 diabetes mellitus (T2DM) patients with or without diabetic peripheral neuropathy (DPN).

METHODS

149 T2DM patients (DPN group and non-DPN group) and 60 healthy volunteers (control group) were enrolled. We measured the absolute difference of fascicle length (FL), pennation angle (PA), and shear wave velocity (SWV) of both MG in neutral position and maximal ankle joint's plantar flexion and calculated ΔFL, ΔPA, and ΔSWV. These three parameters, along with muscle thickness (MT), were compared among the three groups.

RESULTS

In the DPN group, the MG's MT, ΔPA, and ΔSWV were significantly lower than in the non-DPN group (p < 0.01); these parameters achieved the highest scores in the control group (p < 0.01). The area under the receiver operating characteristic curve of the combination of ΔSWV and ΔFL was the largest for predicting inpatients with or without DPN.

CONCLUSIONS

Decreased muscle mass (MT) and muscle contractibility (ΔFL and ΔSWV) were detected in patients with T2DM, with or without DPN. ΔSWV and ΔFL of the MG showed high-diagnostic accuracy for DPN warning signs.

Two-dimensional ultrasound and two-dimensional shear wave elastography on femoral and saphenous neuropathy in patients with type 2 diabetes mellitus

Objective

This study aims to examine the value of two-dimensional (2D) ultrasound and two-dimensional shear wave elastography (2D-SWE) in evaluating femoral nerve (FN) and saphenous nerve (SN) neuropathy in patients with type 2 diabetes mellitus (T2DM).

Materials and methods

According to the diabetic peripheral neuropathy (DPN) diagnostic criteria, 60 patients with T2DM were enrolled and divided into 35 T2DM patients without DPN (non-DPN group) and 25 T2DM patients with DPN (DPN group). The control group consisted of another 15 healthy volunteers. The width, thickness, cross-sectional area (CSA), and perimeter of the FN and SN in the lower extremities were measured with 2D ultrasound. The average shear wave velocity (SWV) of the FN and SN was measured by 2D-SWE. Parameters of the left and right lower extremities were compared in each group, and the above parameters were compared among groups. The correlations between ultrasonographic and laboratory parameters were evaluated, and the independent influencing factors of SWV of the FN and SN were analyzed.

Results

The width, thickness, CSA, perimeter, and SWV of FN and SN in the DPN group were greater than those in the non-DPN groups and control group (P < 0.05). The width, thickness, CSA, perimeter, and SWV of the FN and SN in the non-DPN group were greater than those in the control group (P < 0.05). The CSA of FN was positively correlated with FPG, HbA1c, and TG (r = 0.34–0.69, P < 0.01). The perimeter of FN was positively correlated with FPG, HbA1c, and TG (r = 0.37–0.68, P < 0.01). The perimeter of the FN was negatively correlated with IgF-1 (r = −0.31, P < 0.05). The CSA of the SN was positively correlated with FPG and TG (r = 0.26–0.42, P < 0.05). The perimeter of the SN was positively correlated with FPG and TG (r = 0.37–0.39, P < 0.01). The SWV of FN and SN were positively correlated with FPG and TG (r = 0.35–0.57, P < 0.01; r = 0.43–0.49, P < 0.01). FPG and TG were independent influencing factors of the SWV of the FN and SN (P < 0.05).

Conclusion

2D ultrasound and 2D-SWE could be used to non-invasively, objectively, and accurately evaluate the abnormal changes of the FN and SN in patients with T2DM. It has important clinical significance for the early diagnosis of DPN and the curative effect evaluation.

Shear Wave Elastography of the Coracohumeral Ligament With Frozen Shoulder in Different Stages

OBJECTIVES

To study the shear wave elastography (SWE) of the coracohumeral ligament (CHL) in different stages of frozen shoulder and to analyze its correlation with the visual analogue scale (VAS) score and shoulder range of motion (ROM).

METHODS

Sixty-four patients with frozen shoulder were divided into three stages: stage I (freezing phase), stage II (frozen phase), and stage III (thawing phase). The SWE of the CHL of the affected and healthy sides was measured and compared in the different stages. The VAS score and ROM of the affected side were evaluated, and their correlation with the SWE of the CHL was analyzed in the different stages.

RESULTS

In stage I frozen shoulder, the SWE of the CHL on the affected side was lower than that on the healthy side, while in stages II and III, the SWE on the affected side was higher (P = .001 for all). The SWE of the CHL of the affected side was different across the three stages; the SWE in stages II and III higher than that in stage I (P < .01), while the difference between stages II and III was not significant (P > .05). The SWE of the CHL of the affected side was negatively correlated with the VAS score but not with forward flexion (Ff), external rotation (Er) or internal rotation (Ir) in stage I; in stages II and III, it was positively correlated with the VAS score and negatively correlated with Ff, Er, and Ir.

CONCLUSIONS

The CHL stiffness of the affected side and its correlation with the shoulder VAS score and ROM are different for different stages of frozen shoulder.

Shear wave elastography as a quantitative biomarker of diabetic peripheral neuropathy: A systematic review and meta-analysis

Background

Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes and the strongest initiating risk factor for diabetic foot ulceration. Early diagnosis of DPN through screening measures is, therefore, of great importance for diabetic patients. Recently, shear wave elastography (SWE) has been used as a method that is complementary to neuroelectrophysiological examination in the diagnosis of DPN. We aimed to conduct a meta-analysis based on currently available data to evaluate the performance of tibial nerve stiffness on SWE for diagnosing DPN.

Methods

Both PubMed, EMBASE, the Cochrane Library, and Web of Science were searched for studies that investigated the diagnostic performance of SWE for DPN up to March 1th, 2022. Three measures of diagnostic test performance, including the summary area under receiver operating characteristics curve (AUROC), the summary sensitivity and specificity, and the summary diagnostic odds ratios were used to assess the diagnostic accuracy of SWE. All included studies were published between 2017 and 2021.

Results

Six eligible studies (with 170 DPN patients, 28 clinically defined DPN patients, 168 non-DPN patients, and 154 control participants) that evaluated tibial nerve stiffness were included for meta-analysis. The summary sensitivity and specificity of SWE for tibial nerve stiffness were 75% (95% confidence interval [CI]: 68–80%) and 86% (95% CI: 80–90%), respectively, and the summary AUROC was 0.84 (95% CI: 0.81–0.87), for diagnosing DPN. A subgroup analysis of five two-dimensional SWE studies revealed similar diagnostic performance, showing the summary sensitivity and specificity of 77% (95% CI: 69–83%) and 86% (95% CI: 79–91%), respectively, and a summary AUROC value of 0.86 (95% CI: 0.83–0.89).

Conclusions

SWE is found to have good diagnostic accuracy for detecting DPN and has considerable potential as an important and noninvasive adjunctive tool in the management of patients with DPN.

A preliminary animal study on the prediction of nerve block success using ultrasonographic parameters

This study aimed to evaluate the diagnostic value of ultrasonographic parameters as an indicator for predicting regional nerve block success. Ultrasound-guided sciatic nerve block was performed in seven dogs using either 2% mepivacaine (nerve-block group) or saline (sham-block group). The cross-sectional area (CSA), nerve blood flow (NBF), and shear wave velocity (SWV) of the sciatic nerve (SWV_N), SWV of the biceps femoris muscle (SWV_M), and their ratio (SWV_NMR) were measured at 0, 30, 60, and 90 min after the nerve block as well as the change rate of each parameter from the baseline. A receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic value of each parameter in the prediction of nerve block success. No significant changes were observed in the CSA or NBF in association with the nerve block. The SWV_N and SWV_NMR in the nerve-block group were significantly higher than those in the sham-block group at 90 min and at 30, 60, and 90 min, respectively (p < 0.05). The change rates of SWV_N and SWV_NMR in the nerve-block group were significantly higher than those in the sham-block group at all time points (p < 0.05). The ROC curve analysis showed that SWV_N had a moderate diagnostic accuracy (area under the curve [AUC], 0.779), whereas SWV_NMR and change rates of SWV_N and SWV_NMR had a high diagnostic accuracy (AUC, 0.947, 0.998, and 1.000, respectively). Ultrasonographic evaluation of the SWV_N and SWV_NMR could be used as indicators for predicting nerve block success.

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

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.

Supersonic shear wave imaging of the tibial nerve for diagnosis of diabetic peripheral neuropathy: A meta-analysis

BACKGROUND

Diabetic peripheral neuropathy (DPN) is the most common diabetes-associated complication and imposes a significant burden to healthcare systems. Thus, early diagnosis of DPN is extremely critical for management and outcome of diabetic patients. Supersonic Shear Wave Imaging (SSI) enables the noninvasive measurement of nerve stiffness. However, previous studies on SSI in the diagnosis of DPN were limited in sample sizes and reported various results. In this meta-analysis, we aimed to obtain comprehensive evidence on the value of tibial nerve stiffness measurement by SSI in the diagnosis of DPN.

METHODS

A comprehensive literature search in English and Chinese electronic database was conducted for studies (published until January 25, 2022) that investigated the diagnostic performance of tibial nerve stiffness measurement by SSI for detecting DPN. Summary receiver operating characteristics (SROC) modelling was constructed to conduct the meta-analysis of diagnostic accuracy of SSI for detecting DPN.

RESULTS

Finally, a total of 12 eligible studies with 1325 subjects were included for evaluation, and a meta-analysis was conducted to evaluate the diagnostic performance of tibial nerve stiffness measurement by SSI for detecting DPN. For tibial nerve stiffness measurement by SSI, the summary sensitivity and specificity for the diagnosis of DPN were 80% (95% confidence interval [CI]: 73%-86%) and 86% (95% CI: 82%-89%), respectively. The summary area under the ROC curve (AUROC) value of the SROC was 0.90 (95% CI: 0.87-0.92), for diagnosing DPN. A subgroup analysis of 11 SSI studies from China revealed similar diagnostic performance, with a summary sensitivity of 79% (95% CI: 72%-85%), specificity of 86% (95% CI: 82%-89%) and summary AUROC value of the SROC of 0.90 (95% CI: 0.87-0.92) for diagnosing DPN.

CONCLUSIONS

Our meta-analysis suggests that a tibial nerve stiffness measurement by SSI shows good performance in diagnosing DPN and has considerable potential as a noninvasive tool for detecting DPN.

Shear Wave Elastography in the Diagnosis of Peripheral Neuropathy in Patients With Chronic Kidney Disease Stage 5

OBJECTIVE

To observe the feasibility of shear wave elastography (SWE) in the diagnosis of peripheral neuropathy in patients undergoing hemodialysis [chronic kidney disease stage 5 dialysis (CKD5D)].

METHODS

Forty patients with CKD5D were divided into a uremic peripheral neuropathy (UPN) group (n = 25) and a non-UPN group (n = 15) according to the results of a neuro-electrophysiological examination. Sixteen healthy control subjects were also enrolled in this study. Two-dimensional ultrasound examination was conducted, and SWE was then performed to measure Young's modulus of the tibial nerve. The left and right diameters (D1), anterior and posterior diameters (D2), perimeter (C), cross-sectional area (CSA), and Young's modulus (E) were measured three times at the same non-entrapment site. The average values were recorded and calculated. The following evaluation indices were also analyzed: sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC).

RESULTS

D1, D2, C, and CSA were not significantly different among the three groups (P > 0.05). However, the difference in the E value among the three groups was statistically significant (P < 0.05). The AUC was 0.889 based on the E value. Using a tibial nerve E value of 48.35 kPa as the cutoff value, the sensitivity, specificity, PPV, and NPV were 86.0%, 84.0%, 81.1%, and 88.1%, respectively.

CONCLUSIONS

SWE is useful for the diagnosis of peripheral neuropathy in patients with CKD5D. Young's modulus of 48.35 kPa for the tibial nerve is the optimal cutoff value and has the best diagnostic efficiency for peripheral neuropathy in CKD5D patients.

Value of shear wave elastography combined with the Toronto clinical scoring system in diagnosis of diabetic peripheral neuropathy

To evaluate the diagnostic values of shear wave elastography (SWE) alone and in combination with the Toronto clinical scoring system (TCSS) on diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM).The study included 41 DPN patients, 42 non-DPN patients, and 21 healthy volunteers. Conventional ultrasonography and SWE were performed on the 2 sides of the tibial nerves, and cross-sectional area (CSA) and nerve stiffness were measured. TCSS was applied to all patients. A receiver operating characteristic curve analysis was performed.The stiffness of the tibial nerve, as measured as mean, minimum or maximum elasticity, was significantly higher in patients in the DPN group than the other groups (P < .05). The tibial nerve of subjects in the non-DPN group was significantly stiffer compared to the control group (P < .05). There was no significant difference of the tibial nerve CSA among the 3 groups (P > .05). Mean elasticity of the tibial nerve with a cutoff of 71.3 kPa was the most sensitive (68.3%) and had a higher area under the curve (0.712; 0.602-0.806) among the 3 shear elasticity indices for diagnosing DPN when used alone. When combining SWE with TCSS in diagnosing DPN, the most effective parameter was the EMax, which yielded a sensitivity of 100.00% and a specificity of 95.24%.SWE is a better diagnostic tool for DPN than the conventional ultrasonic parameter CSA, and a higher diagnostic value is attained when combining SWE with TCSS.

Shear wave elastography of the tibial nerve in healthy subjects

The purpose of this study is to investigate sonoelastographic features of the tibial nerve.The study included 72 tibial nerves in 36 healthy subjects. High resolution ultrasound and Shear wave elastography were used to evaluate the tibial nerve. Cross sectional area and stiffness were measured.The mean cross sectional area of the tibial nerve was 13.4 mm2. The mean shear elastic modulus of the tibial nerve in the short axis was 23.3 kPa. The mean shear elastic modulus of the tibial nerve in long axis was 26.1 kPa. The tibial nerve elastic modulus also showed no correlation with cross sectional area neither in the long axis nor short axis. Age, height, weight, and body mass index showed no correlation with tibial nerve elastic modulus in short or long axes.The elastic modulus of the tibial nerve has been determined in healthy subjects and can serve as a reference for future assessment of polyneuropathy.

Shear wave elastography of the ulnar nerve at the forearm

The study included 38 ulnar nerves in 20 healthy subjects. High-resolution ultrasound and Shear wave elastography were used to evaluate the ulnar nerve at the mid forearm. The mean cross-sectional area of the ulnar nerve was 7.1 mm2. The mean shear elastic modulus of the nerve in the short axis was 27.4 kPa. The mean shear elastic modulus of the nerve in long axis was 24.7 kPa. No statistical relation could be noted between elasticity measurements in long and short axes. The ulnar nerve elastic modulus also showed no correlation with CSA neither in the long axis nor short axis. Age, height, weight, and body mass index showed no correlation with the ulnar elastic modulus in short or long axes. The elastic modulus of the ulnar nerve has been determined in healthy subjects and can serve as a reference for future assessment of compressive neuropathies of the ulnar nerve.

Application of High-Resolution Ultrasound on Diagnosing Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus (DM). The typical manifestation is a length-dependent "glove and sock" sensation. At present, diagnosis is mainly dependent on clinical manifestations. Since the pathogenesis is not clear, there are no effective treatment measures. Management consists mainly of glucose control, peripheral nerve nutrition, and other measures to delay the progress of the disease; early diagnosis is therefore crucial to improving prognosis and quality of life for patients with DPN. Due to the lack of obvious symptoms in 50% of patients and the low sensitivity of neuro-electrophysiology to small fibers, the missed diagnosis rate is high. High-resolution ultrasound (HRU), as a convenient noninvasive tool, has been proven by many studies to have excellent clinical value in diagnosing DPN. With the development of related new technology, HRU shows promise for the screening, diagnosing, and follow-up of DPN, which could serve as a biomarker and provide new diagnostic insights. In this paper, we review the ability of HRU to detect nerve cross-sectional area and blood flow, and echo and other image changes, and in showing the characteristics of peripheral nerve morphological changes in patients with DPN. We also explore the application of two other recent technological developments-shear wave elastography (SWE) and ultrasound scoring systems-in improving the diagnostic efficiency of HRU in peripheral neuropathy.

Gold Standard for Diagnosis of DPN

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus. It often causes symmetrical paresthesia, loss of sensation, and hyperalgesia. Without early intervention, it might lead to diabetic foot ulceration, gangrene, and subsequent amputation in people with diabetes. DPN is an insidious disease and often underdiagnosed. This paper reviews the current national and international prevalence of DPN, screening methods for early DPN, including quantitative sensory measurement, neurological function scoring system, confocal microscopy, and high-frequency ultrasound, and summarizes the related research progress, clinical application, and development prospects of these methods in recent years.

Quantitative Musculoskeletal Ultrasound

Ultrasound (US) imaging plays a crucial role in the assessment of musculoskeletal (MSK) disorders. Several quantitative tools are offered by US systems and add information to conventional US imaging. This article reviews the quantitative US imaging tools currently available in MSK radiology, specifically focusing on the evaluation of elasticity with shear-wave elastography, perfusion with contrast-enhanced US and noncontrast superb microvascular imaging, and bone and muscle mass with quantitative US methods. Some of them are well established and already of clinical value, such as elasticity and contrast-enhanced perfusion assessment in muscles and tendons. MSK radiologists should be aware of the potential of quantitative US tools and take advantage of their use in everyday practice, both for clinical and research purposes.

Shear wave elastography of the saphenous nerve

The purpose of this study is to study sonoelastographic features of the saphenous nerve.The study included 72 saphenous nerves in 36 healthy subjects. High resolution ultrasound and Shearwave elastography were used to evaluate the saphenous nerve. Cross sectional area (CSA) and stiffness were measured.The mean CSA of the saphenous nerve was 5.7 mm. The mean shear elastic modulus of the saphenous nerve in the short axis was 29.5 kPa. The mean shear elastic modulus of the saphenous nerve in long axis was 29.9 kPa. The saphenous nerve elastic modulus also showed no correlation with CSA in neither the long axis nor short axis. Positive correlation between elasticity measurements in the long and short axes. Age, height, weight, and BMI showed no correlation with saphenous nerve elastic modulus in short or long axes.The elastic modulus of the saphenous nerve has been determined in healthy subjects and can serve as a reference for future assessment of the saphenous nerve before different procedures.

Chronic effects of muscle and nerve-directed stretching on tissue mechanics

Tissue-directed stretching interventions can preferentially load muscular or nonmuscular structures such as peripheral nerves. How these tissues adapt mechanically to long-term stretching is poorly understood. This randomized, single-blind, controlled study used ultrasonography and dynamometry to compare the effects of 12-wk nerve-directed and muscle-directed stretching programs versus control on maximal ankle dorsiflexion range of motion (ROM) and passive torque, shear wave velocity (SWV; an index of stiffness), and architecture of triceps surae and sciatic nerve. Sixty healthy adults were randomized to receive nerve-directed stretching, muscle-directed stretching, or no intervention (control). The muscle-directed protocol was designed to primarily stretch the plantar flexor muscle group, whereas the nerve-directed intervention targeted the sciatic nerve tract. Compared with the control group [mean; 95% confidence interval (CI)], muscle-directed intervention showed increased ROM (+7.3°; 95% CI: 4.1-10.5), decreased SWV of triceps surae (varied from -0.8 to -2.3 m/s across muscles), decreased passive torque (-6.8 N·m; 95% CI: -11.9 to -1.7), and greater gastrocnemius medialis fascicle length (+0.4 cm; 95% CI: 0.1-0.8). Muscle-directed intervention did not affect the SWV and size of sciatic nerve. Participants in the nerve-directed group showed a significant increase in ROM (+9.9°; 95% CI: 6.2-13.6) and a significant decrease in sciatic nerve SWV (> -1.8 m/s across nerve regions) compared with the control group. Nerve-directed intervention had no effect on the main outcomes at muscle and joint levels. These findings provide new insights into the long-term mechanical effects of stretching interventions and have relevance to clinical conditions where change in mechanical properties has occurred.NEW & NOTEWORTHY This study demonstrates that the mechanical properties of plantar flexor muscles and sciatic nerve can adapt mechanically to long-term stretching programs. Although interventions targeting muscular or nonmuscular structures are both effective at increasing maximal range of motion, the changes in tissue mechanical properties (stiffness) are specific to the structure being preferentially stretched by each program. We provide the first in vivo evidence that stiffness of peripheral nerves adapts to long-term loading stimuli using appropriate nerve-directed stretching.

Application value of conventional ultrasound and real-time shear wave elastography in patients with type 2 diabetic polyneuropathy

PURPOSE

To explore the application value of conventional ultrasound and real-time shear wave elastography (SWE) to the tibial nerve (TN) and the common peroneal nerve (CPN) in diabetic peripheral neuropathy (DPN).

MATERIALS AND METHODS

Thirty-three healthy volunteers, 33 diabetic patients without DPN, and 30 diabetic patients with DPN were enrolled in this study. The anteroposterior diameter (APD), the cross-sectional area (CSA), and the perimeter of the TN and the CPN were measured by conventional ultrasound, and the stiffness of the nerves was measured by SWE.

RESULTS

The conventional ultrasound parameters and stiffness of the TN in patients with DPN were significantly larger than those of the other two groups (P < 0.01). The conventional ultrasound parameters of the CPN were significantly higher in patients with DPN than in the other two groups (P < 0.01).The patients with DPN demonstrated a greater stiffness of the CPN compared to the control group (P < 0.05). The comparison of all parameters for the left and right TNs and CPNs among the three groups showed no significant difference. The area under the curve (AUC) of TN stiffness for the diagnosis of DPN was significantly greater than that of conventional ultrasound parameters.

CONCLUSION

The conventional ultrasound parameters and the stiffness of the TN and the CPN were significantly higher in patients with DPN. The stiffness of the TN could better diagnose DPN than conventional ultrasound parameters. In short, conventional ultrasound and SWE of nerves are of good application value in the diagnosis of DPN.

Influence of limb position on assessment of nerve mechanical properties by using shear wave ultrasound elastography

INTRODUCTION

Evaluation of nerve mechanical properties has the potential to improve assessment of nerve impairment. Shear wave velocity, as measured by using shear wave (SW) ultrasound elastography, is a promising indicator of nerve mechanical properties such as stiffness. However, elucidation of external factors that influence SW velocity, particularly nerve tension, is required for accurate interpretations.

METHODS

Median and ulnar nerve SW velocities were measured at proximal and distal locations with limb positions that indirectly altered nerve tension.

RESULTS

Shear wave velocity was greater at proximal and distal locations for limb positions that induced greater tension in the median (mean increase proximal 89.3%, distal 64%) and ulnar (mean increase proximal 91.1%, distal 37.4%) nerves.

DISCUSSION

Due to the influence of nerve tension when SW ultrasound elastography is used, careful consideration must be given to limb positioning.

Ultrasound elastography for the evaluation of peripheral nerves: A systematic review

Peripheral nerve disorders are commonly encountered in clinical practice. Electrodiagnostic studies remain the cornerstone of the evaluation of nerve disorders. More recently, ultrasound has played an increasing complementary role in the neuromuscular clinic. Ultrasound elastography is a technique that measures the elastic properties of tissues. Given the histological changes that occur in diseased peripheral nerves, nerve ultrasound elastography has been explored as a noninvasive way to evaluate changes in nerve tissue composition. Studies to date suggest that nerve stiffness tends to increase in the setting of peripheral neuropathy, regardless of etiology, consistent with loss of more compliant myelin, and replacement with connective tissue. The aim of this systematic review is to summarize the current literature on the use of ultrasound elastography in the evaluation of peripheral neuropathy. Limitations of ultrasound elastography and gaps in current literature are discussed, and prospects for future clinical and research applications are raised.