Application Of Two-dimensional Ultrasound Combined With Shear Wave Velocity In Diagnosis Of Carpal Tunnel Syndrome

Objective:In this study,we aim to assess the application of measuring cross-section area(CSA)of median nerve(MN)at wrist and forearm level and thickness of transverse carpal ligament in diagnosis of carpal tunnel syndrome(CTS),and to investigating the diagnostic value of the shear wave velocity(SWV)at wrist and forearm level in patients with CTS.To explore the clinical value of two-dimensional ultrasound combined with shear wave velocity in noninvasive diagnosis of carpal tunnel syndrome.Methods:Between Jan 2019 and Feb 2020,a total of 31 hospitalized patients(59 wrist)with CTS,confirmed by electromyography and postoperative pathology,and 25 healthy volunteers(50 wrist)were assigned into case group and control group,respectively.the CSA of MN at the level of pronator quadratus(MN-CSA-PQ),Transverse wrise crease(MN-CSA-TWC),hook hamate bone(MN-CSA-HHB)were separately measured by two-dimensional ultrasound.SWV at three previously mentioned levels(MN-SWV-PQ,MN-SWV-TWC,MN-SWV-HHB)were assessed through virtual touch tissue quantification(VTQ).The thickness of transverse carpal ligament(T-TCL)at pisiform bone level.All of these variables were compared by t test.We also compared the ratio of MN-SWV-TWC and MN-SWV-PQ,as well as the ratio of MN-CSA-TWC and MN-CSA-PQ。All statistical analyses were conduct by SPSS version 23.0.Results:On the one hand,the mean MN-CSA-TWC and MN-CSA-HHB(0.18 cm2and 0.19 cm2),as well as T-TCL(0.21 cm)in case group were larger than those in control group,(0.12 cm~2、0.13 cm~2 and 0.19cm,respectively,all p value<0.01),whereas,the mean MN-CSA-PQ was not significantly statistical different between these two groups(0.11 cm~2 and 0.10 cm~2,respectively,p>0.05).On the other hand,the MN-SWV-TWC in case group was significantly higher than control group(4.95 m/s and3.43 m/s,respectively,p<0.01),however,there were no difference existing between MN-SWV-PQ(2.84 m/s and 2.86 m/s,p>0.05)and MN-SWV-HHB(3.78 m/s and3.45 m/s,p>0.05).As for the ratio of MN-SWV-TWC and MN-SWV-PQ,and the ratio of the ratio of MN-CSA-TWC and MN-CSA-PQ,significant differences were still observed(p<0.01).Indeed,among these variables,the AUC of MN-CSA-TWC was largest(0.86),when diagnosing CTS,with sensitivity of 90.9%and specificity of 72.2%,the best cut-off value was 0.14 cm2,meanwhile,the ratio of MN-SWV-TWC and MN-SWV-PQ has best specificity of 94.4%,with sensitivity of 63.6%and AUC of 0.82,the best cut-off ratio was 1.46.Conclusions:The application of MN-CSA and MN-SWV offer an easy method in diagnosis of CTS,especially sequential detection with the ratio of the ratio of MN-SWV-TWC and MN-SWV-PQ,and MN-CSA-TWC would allow for effective and noninvasive diagnostic method of CTS,which still need larger samples to validate.