| Background:The magnetic resonance (MR) research of carpal tunnel was begun in the last century. Carpal tunnel cross-section image of MR provided the most comprehensive information, which could distinguish among all the wrist tendons, nerves, ligament, blood vessels, and it can display carpal tunnel wall contour, and also carpal tunnel coronal images can help to distinguish the carpal bones. As the research reported that the MR image structure of median nerve in planar range of carpal tunnel was basically agreed with fault gross anatomy. MR image is also considered as the most valuable imaging method in the diagnosis of carpal tunnel syndrome at this stage. Clinically, the traditional magnetic resonance (MR) research of carpal tunnel syndrome is more focused on the research of median nerve, and mostly remained in the gross morphology change. The magnetic resonance associated with carpal tunnel syndrome included the enlargement of the median nerve, flatten and increased median nerve signal of T2WI. Formerly, the foundation studies of gross anatomy and sectional anatomy of specimen carpal tunnel structure cannot fully represented living MRI imaging anatomy, and most of the existing carpal tunnel in the middle of neuroanatomy quantitative data were from foreign people, which couldn’t be the tomographic images reference standard of the diagnosis of Carpal Tunnel Syndrome (CTS) of China. It has been reported about carpal tunnel median nerve anatomy quantitative MRI of the patients who clinically has been clearly diagnosis of CTS, but there were rarely reports about morphology quantitative anatomy research of normal people which can be an important reference. Therefore, by means of collecting young normal people wrist ct MRI image data of our country, the topic quantitatively studied the anatomy morphology characteristics of median nerve in the wrist tube, and obtained the data of expansion rate, flatness rate and curving rate, which can provide with valuable reference to diagnose CTS.Purpose:It has been reported about carpal tunnel median nerve anatomy quantitative MRI of the patients who clinically has been clearly diagnosis of CTS, but there were rarely reports about morphology quantitative anatomy research of normal people which can be an important reference. By means of collecting young normal people wrist ct MRI image data of our country, the topic quantitatively studied the anatomy morphology characteristics of median nerve in the wrist tube, which can provide with valuable reference to diagnose CTS.Methods:The study totally collected 28 cases,56 image data of contralateral wrist MRI, including 13 cases of male,15 cases of female, whose ages between 21-33 years old, averaged 23.6 years. All volunteers were ruled out wrist injury history and related history, bilateral carpal tunnel, sensory functions were normal by specialized surgeon examination. With knee coil, volunteers were in supine position, one hand stretched out over the head, the contralateral hand put on body side, using SIEMENS Avanto 1.5T MRI scanner to measure partial center scanning field. Scanning direction: be priority to the axis, complementary with coronal and sagittal position. By directly measuring the length diameter and short diameter of median nerve on distal radius plane, lenticular proximal bone plane and hooked bone plane, and then calculated the three cross-sectional areas, flatness rations and swelling rates of median nerve. Cross-sectional area (CSA) was calculated by length diameter multiplied short diameter of median nerve. Flatteningrate of the median nerve (MNFR) was calculated by length diameter divided short diameter. Median nerve swelling rate (MNSR) was calculated by lenticular proximal bone plane CSA divided distal radius plane CSA. Using IBM SPSS20.0 statistical software to statistically analyse the imaging anatomy measurement data, measurement data is showed by mean ± standard deviation (±SD). Two paired sample data uses two paired sample t test, and two independent samplesdate use two independent samples t test. Using correlation analysis to explore the correlation of data, and using Person method to handle normal distribution, using Spearman correlation analysis to handle non-normal data, and set the significance level to 0.05. Compare measure indexes among different gender, different side of the body, and further statistically analyse the CSA, MNFR and MNSR with age, height, weight.Results:There was no CSA statistical difference between left and right hand of young people, and after fixed gender factors, it also didn’t have statistical difference. As a result, based on the merger and average bilateral carpal tunnel CSA data to compare different gender of CSA, also didn’t have statistical difference. After fixing left or right hand factors, to compare the CSA, men and women’s data had no statistical difference. MNFR of all volunteers’left side ranged from 1.04 to 3.75, with an average data of 1.82, and MNFR of right side ranged from 1.08 to 2.26, with an average data of 1.77. Men’s left MNFR ranged from 1.04 to 2.21,1.63 on average, and from 1.04 to 2.24 on the right side, an average of 1.65. Women’s left MNFR ranged from 1.42 to 3.75,1.98 on average, and from 1.44 to 2.26 on the right side, an average of 1.86. Right and left MNFR had no statistical difference, after fixing gender factors, MNFR also no statistical difference between. After averagely bilateral carpal tunnel to compare MNFR statistically difference between men and women (t= 2.126, P= 0.043). After fixing left and right hand factors to compare MNFR, men and women had no statistical difference. All volunteers’MNSR, left was 1.09 averagely, and the right was 1.12 averagely. The left MNSR of men, whether in under the condition of fixed gender factors or not, both had no statistical difference. After averaged MNSR, left and right was no statistical difference between different genders. After fixing acupoint factors, no statistical difference between the sexes compared different MNSR. MNFR statistically negative correlation with height (r=0.388, P=0.388). MNFR and weight had no statistical correlation (r=0.322, P=0.095). MNFR had no statistical correlation with age (r=0.071, P=0.720). The CSA indicators, had the correlation of age (r=0.004, P=0.004), and the correlation of weight was (r =0.142, P=0.142), and height was (r=0.129, P=0.129), and did not find the statistical correlation between age, height and weight. For MNSR, the correlation with age was (r=0.137, P=0.486), and the correlation of weight was (r=0.145, P=0.145), and the height was (r=0.110,P=0.110), also did not find the statistical correlation between age, height and weight.Conclusion: As for its non-invasive, high soft tissue resolution, comprehensive advantages of various imaging sequences, MRI can show the morphology and microstructure of the wrist tube structure functions in good shape, and the study is to proof that MRI is the best imaging method to display the structure of muscles, nerves, ligaments, tendons, blood vessels, and some other wrist structure, which can provide strong evidence to support diagnosis, preoperative and postoperative evaluation of CTS. At the same time, the study results show that the median nerve flatness rates of different genders has significant differences in China, and there are significant differences between Chinese and western people. Flatness rate has a negative correlation of height. Therefore, the establishment of Chinese clinical CTS diagnostic criteria which based on MRI must match the Chinese actual anatomic parameters. |
