ABSTRACT
OBJECTIVE: To evaluate the clinical value of high-frequency ultrasonagraphy in testing carpal canal structure in the diagnosis of patients with occupational hand-arm vibration disease( HAVD). METHODS: Eighteen patients with occupational mild HAVD( 36 wrists) were selected as the case group and 20 healthy volunteers( 40 wrists) were enrolled as the control group by using convenience sampling method. The color doppler ultrasound was used to measure the crosssectional areas( CSA) of median nerve at the level of pisiform bone,the thickness of transverse carpal ligament,and the internal diameter of median nerve and the CSA of median nerve at the level of hamate hook of the 2 groups. Fisher discriminant analysis and receiver operating characteristic( ROC) curve were performed to assess the effect of diagnosing HAVD with the CSA of median nerve at the level of pisiform bone in patients with HAVD. RESULTS: The CSA of median nerve at the level of pisiform bone in both hands was smaller than that of the control group( P < 0. 01). However,there was no statistical significance in the thickness of transverse carpal ligament of both hands,the internal diameter of median nerve and the CSA of median nerve at the level of hamate hook in the case and control groups( P > 0. 05). Through the Fisher discriminant analysis which was carried on and the distinction equation which was established meanwhile by using the CSA of median nerve at the level of pisiform bone in both hands as HAVD diagnostic criterion,the HAVD predictive accuracy rate was 78. 9%. The ROC curve was underway with the discriminant score as an indicator for distinguishing HAVD,and the result showed that the area under the curve was 0. 842,with sensitivity of 75. 00% and specificity of 88. 90%. CONCLUSION: High-frequency ultrasonography can be used to observe and quantify the imaging changes of carpal canal structure in patients with HAVD,which can provide objective and scientific diagnostic basis for the diagnosis of HAVD.
ABSTRACT
The aim of this study was to determine the course of the median nerve and its adjacent structures in the carpal canals of 8 healthy dogs by using high-frequency transducers. Before performing ultrasonography, the transverse and posteroanterior diameters as well as the perimeter of the carpus were measured at just proximal to the side of the carpal pad. The anatomical structures were then determined at two levels of the carpal canal, which were named the proximal and distal levels, on the transverse sonograms. The cross-sectional areas, perimeters and the transverse and posteroanterior diameters of the median nerve were measured at these levels. Although all the measurements were larger at the proximal level, significant differences between the proximal and distal levels were determined for the cross-sectional area, the perimeter and the transverse diameter of the median nerve. On the transverse sonogram, the deep digital flexor tendon was seen in almost the center of the carpal canal like a comma shape and also it had a small concavity on the caudal side. The superficial digital flexor tendon was seen as an ovoid shape on the transverse sonograms and it was located nearly at the posterior side of the carpal canal. Both tendons were seen as intermediate-grade echogenic structures. The median artery was located inside of the concavity of the deep digital flexor tendon. Also, the median nerve was seen at the posteromedial side of the median artery. As a result of this study, the cross-sectional areas of the median nerve ranged between 1.01-2.68 mm2 at the proximal level and between 0.93-1.91 mm2 at the distal level.