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Objective To discuss MRI and pathological features of intracranial hemangioblastoma.Methods MRIdata of 26 cases of hemangioblastoma confirmed with operation and pathology were analyzed retrospectively.Results There were 22 cases with single lesion and multiple lesions in 4 eases.And a total of 31 lesions located in the posterior cranial fossa,including 14 lesions in right cerebellar hemispheres,9 lesions in left cerebellar hemispheres,2 lesions in cerebellar inferior vermis,4 lesions in medulla oblongata,and 2 lesions in fourth ventricle.Ninteen lesions showed cystic nodular type,1 lesion was cystic type,11 lesions showed parenchymal type or partial parenchyma type.Cystic lesions showed long T1 and long T2 signal,T1WI of solid area showed slightly long T1 and slightly long T2 signal,of which 12 lesions were slightly shorter T1 signal.Solid areas significantly enhanced,cystic area had no enhancement,but cystic wall of 3 cystic nodular lesions were slightly enhanced.DWI of solid areas showed low signal.MRS showed the peak of Cho obviously increased,and the peaks of Cr and NAA obviously decreased or nearly disappeared,and the high peak of lipids and lactate were observed.Conclusion The conventional and functional MRI of intracranial hemangioblastoma have some characteristics,MRI has a great value in the diagnosis and localization of intracranial hemangioblastoma.
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Objective To discuss MRI and pathological features of intracranial hemangioblastoma.Methods MRIdata of 26 cases of hemangioblastoma confirmed with operation and pathology were analyzed retrospectively.Results There were 22 cases with single lesion and multiple lesions in 4 eases.And a total of 31 lesions located in the posterior cranial fossa,including 14 lesions in right cerebellar hemispheres,9 lesions in left cerebellar hemispheres,2 lesions in cerebellar inferior vermis,4 lesions in medulla oblongata,and 2 lesions in fourth ventricle.Ninteen lesions showed cystic nodular type,1 lesion was cystic type,11 lesions showed parenchymal type or partial parenchyma type.Cystic lesions showed long T1 and long T2 signal,T1WI of solid area showed slightly long T1 and slightly long T2 signal,of which 12 lesions were slightly shorter T1 signal.Solid areas significantly enhanced,cystic area had no enhancement,but cystic wall of 3 cystic nodular lesions were slightly enhanced.DWI of solid areas showed low signal.MRS showed the peak of Cho obviously increased,and the peaks of Cr and NAA obviously decreased or nearly disappeared,and the high peak of lipids and lactate were observed.Conclusion The conventional and functional MRI of intracranial hemangioblastoma have some characteristics,MRI has a great value in the diagnosis and localization of intracranial hemangioblastoma.
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<p><b>BACKGROUND</b>A large amount of biomechanical and clinical evidence from previous studies suggest the efficiency of the two different posterior lumber non-fusion methods, interspinous distraction device (ISDD) and facet screw fixation system (FSS), but the biomechanical comparison of ISDD and FSS has not been thoroughly clarified.</p><p><b>METHODS</b>In the current study, finite element methods were used to investigate the biomechanical comparison of ISDD and FSS. The range of motion (ROM), intradiscal pressure (IDP) and the protective effects gained by maintaining disc heights were evaluated.</p><p><b>RESULTS</b>The ROM was similar between the two non-fusion methods under static standing, flexion and lateral bending. The FSS appeared to be more effective in resisting extension. At the implanted level L3/4, FSS displayed better results for maintaining and increasing posterior disc heights. At the L4/5 level in extension and lateral bending, FSS was better than ISDD, with comparable results observed in other motions. Comparing the posterior and lateral disc heights, FSS appeared to be more effective than ISDD. FSS also had a minor effect on the inferior adjacent segment than ISDD. FSS was more effective in reducing IDP than ISDD in extension.</p><p><b>CONCLUSION</b>Through the finite element analysis study, it can be seen that FSS demonstrates more beneficial biomechanical outcomes than does ISDD, such as being more effective in resisting extension, maintaining and increasing lumbar disc heights and reducing the inferior adjacent IDP in extension.</p>
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Humans , Biomechanical Phenomena , Bone Screws , Finite Element Analysis , Lumbar Vertebrae , General SurgeryABSTRACT
BACKGROUND: The injury of peripheral nerve may cause electroneurographic changes. However, what is the correlation between electroneurographic changes and the extent of nerve injury?OBJECTIVE: To probe into the changes of evoked electroneurography in early stage after nerve injury for clinical application and reference.DESIGN: Paired t-test in three groups of samples.SETTING: Department of Traumatic Orthopaedics People' s Hospital of Beijing University.MATERIALS:The trial was conducted in the Animal Center of the People's Hospital of Beijing University from August 2003 to December 2003. The subjects were 8 adult New Zealand rabbits of SPF grade(weighing 1.5 kg) and either gender from the Animal Center of Medical College of Beijing University.METHODS:The model of nerve injury was made in the 16 tibial nerves of the 8 rabbits, in which one third or two thirds of each nerve was ligated at the same transverse part. The samples were thus divided into three groups: non-injury (normal) group, 1/3 nerve injury group and 2/3 nerve injury group.MAIN OUTCOME MEASURES: The indices of evoked electroneurography, i. e. motor nerve condution velocity, negative M wave amplitude, negative M wave area, maximal M wave amplitude and maximal M wave area were measured in the three groups. The correlation between the extent of nerve injury and the 5 indices was analyzed.RESULTS: All the 5 indices of the 3 groups were significantly different( P＜ 0.05). The mean values of the 5 indices were 1.00 ±0.0,0.97 ±0.18,1.01 ±0.22;0.98 ±0.16 and 0.98 ±0.19 in normal group, 0.76 ±0.12,0.41 ± 0.24, 0.47 ± 0.30, 0.48 ± 0.27 and 0.50 ± 0.29 in 1/3 nerve injury group, and 0. 62±0. 10, 0. 11 ±0. 11, 0. 11 ±0. 10, 0. 12 ±0. 14 and 0.13± 0. 12 in 2/3 nerve injury group. The coefficient of correlation between the 5 indices and the injury were 0. 902, 0. 938, 0. 936, 0. 907, and 0. 914, respectively.CONCLUSION: In the early stage after peripheral nerve injury, the electroneurographic indices negatively correlate with the extent of nerve injury. The negative M wave amplitude and area are relatively more closely correlated with the extent of injury.