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

OBJECTIVES: To evaluate the stiffness of the tibial nerve with two-dimensional shear wave elastography (2D-SWE) and to determine whether 2D-SWE can be used to diagnose diabetic peripheral neuropathy (DPN). METHODS: The study included 70 consecutive diabetic patients with DPN or without DPN and 20 healthy volunteers. The tibial nerve stiffness measured with 2D-SWE was studied. The differences in stiffness values among patients with DPN, patients with clinically defined DPN, patients without DPN, and healthy volunteers based on clinical features and electrodiagnostic tests were evaluated with the Mann-Whitney U test and the Kruskal-Wallis test. Inter- and intraobserver variability was evaluated, and a receiver operator characteristic curve analysis was performed. RESULTS: The tibial nerve stiffness based on mean (EMean), minimum (EMin), and maximum (EMax) shear elasticity indices was significantly higher in patients with DPN and clinically defined DPN than that in patients without DPN and control subjects (p < 0.05). The area under the curve (AUC) for the SWE measurements of EMean, EMin, and EMax was 0.846, 0.867, and 0.821, respectively. An EMin cutoff value of 45.7 kPa had a sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 74.0%, 87.6%, 6.0, and 0.3, respectively. The inter- and intraobserver agreements were excellent for the SWE measurements. CONCLUSIONS: Tibial nerve stiffness is significantly higher in diabetic patients with DPN and clinically defined DPN. The EMean and EMin have a good accuracy for identifying DPN. Minor degree of peripheral nerve lesions appear to might exist in patients with clinically defined DPN, not detectable by electrophysiology. 2D-SWE has a potential use for cases with clinically defined DPN and can be detected with 2D-SWE. KEY POINTS: • 2D-SWE elastography is a noninvasive method that can be used to evaluate precise nerve stiffness for diagnosing DPN. • Minor degree of neurologic lesion might exist early in patients with clinically defined DPN and can be detected by 2D-SWE. • E Min and E Mean of SWE elasticity indices have better diagnostic accuracies than E Max for identifying DPN.

Diagnostic accuracy of point shear wave elastography and transient elastography for staging hepatic fibrosis in patients with non-alcoholic fatty liver disease: a meta-analysis.

OBJECTIVE: This study aimed to assess the accuracy of staging liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD) usingpoint shear wave elastography (pSWE) and transient elastography (TE). SETTING: Relevant records on NAFLD were retrieved from PubMed, Embase, Web of Science and the China National Knowledge Infrastructure databases up to 20 December 2017. A bivariate mixed-effects model was conducted to combine sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and area under the summary receiver operating characteristic curve (AUC) between pSWE and TE. A sensitivity analysis was implemented to explore the source of heterogeneity. PARTICIPANTS: Patients with NAFLD who had a liver stiffness measurement using pSWE and TE before liver biopsy were enrolled according to the following criteria: 2×2 contingency tables can be calculated via the reported number of cases; sensitivity and specificity were excluded according to the following criteria: history of other hepatic damage, such as chronic hepatitis C, concurrent active hepatitis B infection, autoimmune hepatitis, suspicious drug usage and alcohol abuse. RESULTS: Nine pSWE studies comprising a total of 982 patients and 11 TE studies comprising a total of 1753 patients were included. For detection of significant fibrosis, advanced fibrosis and cirrhosis, the summary AUC was 0.86 (95% CI 0.83 to 0.89), 0.94 (95% CI 0.91 to 0.95) and 0.95 (95% CI 0.93 to 0.97) for pSWE, and the summary AUC was 0.85 (95% CI 0.82 to 0.88), 0.92 (95% CI 0.89 to 0.94) and 0.94 (95% CI 0.93 to 0.97) for TE, respectively. The proportion of failure measurement was over tenfold as common with TE using an M probe compared with pSWE. CONCLUSION: pSWE and TE, providing precise non-invasive staging of liver fibrosis in NAFLD, are promising techniques, particularly for advanced fibrosis and cirrhosis.