Ultrasound Elastographic Evaluation Of The Median Nerve In Hemodialysis And Diabetes With Carpal Tunnel Syndrome

BackgroundCarpal tunnel syndrome(CTS)is the most frequent of the compressive syndromes and is defined by compression and/or traction of the median nerve at wrist level.In the great majority of cases,CTS is called idiopathic.Secondary CTS may be related to many factors.Hemodialysis(HD)and diabetes mellitus(DM)is the more common two major causes.Long-term hemodialysis(HD)is a well-known cause of CTS.In patients receiving long-term hemodialysis for 10 years or more,the HD-CTS was increased significantly in the groups patients compared with the value in complication-free patients.Clinical symptoms of HD-CTS are relatively similar to those of idiopathic carpal tunnel syndrome(I-CTS),but the clinical results after surgery between the two types are different.Close observation and routine clinical examination is mandatory to prevent further problems.The number of patients with DM has increased.Diabetic peripheral neuropathy(DPN)is one of the most common and complex complications of DM.Many epidemiological studies have shown that DM has an especially strong relationship with CTS.In one long-term,follow-up study,patients with DM had worse surgical outcomes than patients with I-CTS.First of all,it should be noted that there is no gold standard for a positive diagnosis of CTS.In the diagnosis,in addition to the typical clinical symptoms and signs,electrophysiological examination is still the very important auxiliary diagnosis method.The sensitivity and specificity of the electrophysiology are good.But the accuracy of it depend on the operator's technology.The results can be a significantly different.Because of the expensive equipment and high technical requirements,some areas can not carry out this work.Ultrasonic examination is simple,noninvasive,repeatable.The use of conventional ultrasound examination in the diagnosis of peripheral nerve has been widely used in clinical practice.Ultrasound elastography is a noninvasive technique introduced to measure nerve elasticity,which is an important index for nerve function,and it has recently been used in a variety of research and clinical settings.The elastogram appeared within a rectangular region of interest area as a translucent,color-coded,real-time image superimposed on the B-mode image.The color code indicated the relative stiffness of the tissues within the region of interest and ranged from red(soft)to blue(hard).Green and yellow indicated medium elasticity.The strain indicator on the lateral part of the screen indicated whether the displacement was sufficient to obtain local strains within the region of interest.Ultrasound elasticity imaging score was based on the color distribution of the lesion area.Different physicians give different ratings,affecting the objectivity of the diagnosis.Strain ratio can be more objective to give diagnostic data,to avoid the subjectivity of the elastic image score.Our ultrasonic elastic equipment can calculate the strain ratio between any two regions as a resilience index.In other words,the two regions of interest were sketched out to compare in elastic imaging equipment,calculate strain ratio and infer the relative hardness of lesion and surrounding normal tissue.The greater the strain ratio is,the harder the hardness of the lesion.The aim of this study was to observe the dimensional and elastic ultrasound performance of the median nerve in patients with HD and DM,and to evaluate the staging and severity of the disease,to guide treatment,reduce morbidity,improve quality of life.The innovation of this research lies in some aspects.l)For the first time,real-time ultrasound and elastic imaging techniques were used to evaluate HD-CTS atObjective:The aim of this study was to compare the elasticity of the median nerve(MN)between HD patients without CTS and with CTS,and to evaluate the diagnostic usefulness of the elasticity of the MN in HD-CTS.Material and methods:A total of 71 patients with HD were enrolled in the hospital from March 2012 to December 2015,22 patients with HD without CTS and 49 patients with HD-CTS were selection.All participants were divided into four groups:HD-CTS(0-5 years),HD-CTS(5-10 years),HD-CTS(10-15 years)and HD without CTS according to electrophysiological results.We excluded patients aged under 18 years or whom had already been treated for HD-CTS and patient's wrist injuried and with I-CTS and patients with diabetes and rheumatism.The ultrasound evaluation was performed by means of an ALOKA HI VISION Preirus ultrasound device(HITACHI,Tokyo,Japan)with a multifrequency linear array transducer at frequencies of 6-15 MHz.A frequency of 12.0 MHz was used for B-mode ultrasound,and imaging parameters were adjusted to optimize the examined structures.Observe the shape,direction,and traceability of the median nerve in all participants,and measure and record the cross-sectional area(CSA)value of MN at level of the lentiform bone.The compressibility of the nerve was observed by elastic ultrasound,and subcutaneous fat(SF)was used as a reference medium.The subcutaneous fat and median elasticity ratio(SF/MN strain ratio)was calculated.The stiffness of the median nerve was determined quantitatively.Results:different stages.2)In this study,we use elastic strain ratio to semi-quantitative assess nerve stiffness.It is useful in the diagnosis of the DM-CTS.In this study,we tried to explore a new objective imaging test to assess the progress of HD-CTS and DM-CTS.PART 1 Ultrasound elastographic evaluation of the median nerve in hemodialysis with carpal tunnel syndrome1.The mean CSA value of HD-CTS(0-5 years),HD-CTS(5-10 years),HD-CTS(10-15 years)and control group were 9.9±1.30mm2,11.6±1.6mm2,13.4±2.14mm2 and 9.22±1.43mm2,respectively.The CSA value of the HD-CTS patients group was 12.3±0.02mm2,and the difference of CSA value between the HD-CTS patients group and the control group was statistically significant(p<0.05,t test).There was a significant correlation between CSA value and HD duration(r2=0.612,p<0.05).2.The mean SF/MN strain ratio of HD(0-5 years),HD(5-10 years),HD(10-15 years)and control group were were 1.4±0.28,1.7±0.18,2.0±0.67and1.0±0.21,respectively.The SF/MN strain ratio of the HD-CTS patients group was 1.70±0.46,and the difference of the elasticity between the HD-CTS patients group and the control group was statistically significant(p<0.05,t test).There was a correlation between the SF/MN strain ratio and HD duration(r2 = 0.291,p<0.05)3.In this study,on the basis of empirical ROC analysis,the optimal test thresholds to maximize the sensitivity and specificity for detection of CTS were defined by an SF/MN strain ratio cutoff of 1.8 and a CSA cutoff of 11mm2.The sensitivity and specificity of the CSA and SF/MN strain ratio were 75.0%,92.0%and 79.2%,84.0%,respectively.The AUC of CSA and SF/MN strain ratio were 0.913 and 0.952.4.A summary of electrodiagnostic parameters between the control group and patient group showed significant differences in terms of DML,MNCV,and DSL(p<0.05 by unpaired Student t test).Conclusion1.With the extension of the course of dialysis,the CSA value and SF/MN strain ratio of median nerve in HD-CTS patients increased gradually,suggesting that the swelling and increased stiffness of nerve,the greater the value,the more serious the disease.2.The SF/MN strain ratio can detect neurological stiffness changes slightly before CSA changes.3.The sensitivity and specificity of the combination of ultrasound morphological examination and ultrasonic elastic imaging of peripheral neuropathy are higher than that the application of one of the methods alone.PART 2 The diagnostic value of elastoultrasonography in diabetic patients with carpal tunnel syndromeObjective:The aim of this study was to compare the elasticity of the MN between DM patients with and without CTS,and to evaluate the diagnostic usefulness of the elasticity of the MN in DM-CTS.Material and methods: A total of 140 patients with type 2 diabetes mellitus were enrolled in outpatient and hospitalized from March 2012 to December 2015.All participants were divided into four groups according to electrophysiological results.70 diabetes patients with CTS were assigned to group 1.70 diabetes patients without CTS were assigned to group 2.70 healthy volunteers were assigned to group 3.We excluded patients aged under 18 years,as well as those who had already been treated for CTS and the patients with other diabetic complications and rheumatism.The ultrasound evaluation was performed by means of an ALOKA HI VISION Preirus ultrasound device(HITACHI,Tokyo,Japan)with a multifrequency linear array transducer at frequencies of 6-15 MHz.A frequency of 12.0 MHz was used for B-mode ultrasound,and imaging parameters were adjusted to optimize the examined structures.Observe the shape,direction,and traceability of the median nerve in all participants,and measure and record the cross-sectional area(CSA)of at the lentiform bone.The compressibility of the nerve was observed by elastic ultrasound,and subcutaneous fat(SF)was used as a reference medium.The subcutaneous fat and median elasticity ratio(SF/MN strain ratio)was calculated.The stiffness of the median nerve was determined quantitatively.Results1.The CSA values of group 1,group2 and group3 were 16.49±2.35mm2,10.53±1.63mm2 and 9.07±1.45mm2,respectively.The CSA value of group l was higher than that of group2 and group3,the difference was statistically significant(p<0.05).2.The SF/MN strain ration of group1,group2 and group3 were 2.04 ± 0.64,1.60±0.26,1.28±0.32,respectively.The nerve stiffness of group 1 was higher than that of group2 and group3,the difference was statistically significant(p <0.05).3.In this study,on the basis of empirical ROC analysis,the optimal test thresholds to maximize the sensitivity and specificity for detection of DM-CTS were defined by an SF/MN strain ratio cutoff of 2.0 and a CSA value cutoff of 13mm2.The sensitivity and specificity of the CSA and SF/MN strain ratio were 97.14%,96.67%and 95.71%,98.10%,respectively.4.In this study,there was a correlation between CSA and SF/MN strain ratio(r2=0.961,p <0.05).The CSA was significantly correlated with DML,MNCV,DSL,and amplitude(r2 amplitude =0.935,r2 DML =0.926,r2 DSL=0.658,r2 MNCV=0.951;p<0.01).The SF/MN strain ratio was significantly correlated with DML,MNCV,DSL,and amplitude(r2 amplitude=0.874,r2DML=0.873,r2 DSL=0.873,r2MNCV=0.900;p<0.01).Conclusion1.The sensitivity of SF/MN strain ratio is slightly superior to conventional ultrasound in diagnosing DM-CTS.2.Elastoultrasonography is useful in early diagnosisof DM-CTS.3.The combination of elastoultrasonography and conventional ultrasound is better than the two separate application in the diagnosisof DM-CTS.4.There was a good agreement between the CSA,SF/MN strain ratio and the electrophysiological parameters.