0.05). 100% occlusion was achieved in 18 patients with cerebral aneurysms by using embolization. Conclusion 3D DSA may improve the accuracy in diagnosing SAH and in showing clearly the stereo conformation of aneurysm and the relationship of sac and parent artery. It is helpful in the evaluation and guidance of embolization of cerebral aneurysms.

Objective To explore the pathogenic gene for the family with central nervous system hemangioblastoma (CNS-HB) in Luodian County,Guizhou Province and the pathologic features of familial and sporadic CNS-HB.Methods The peripheral blood from 42 members of the family with CNS-HB was obtained for DNA extraction.The exons 1,2 and 3 of VHL gene were amplified and sequenced by PCR.Light microscopy and immunohistochemical staining were applied for pathological observation of the tumor tissues harvested intraoperatively from 6 cases of the familial CNS-HB and from another 9 cases of sporadic CNS-HB as controls.A total of 9 specimens of familial CNS-HB (6 cystic and 3 solid) and 9 specimens of sporadic CNS-HB (8 cystic and one solid) were harvested.Results VHL gene mutations were not detected among the 42 members of familial CNS-HB.HE staining showed that the tumors were made up of capillary network and large vacuolated interstitial cells with abundant cytoplasm which were pale eosinophilic,polygon-shaped,foamy or ground-glass opaque,and scattered between the capillary network.No nucleus fission or necrosis was observed.Immunohistochemical staining showed the positive expression of Inhibin-α was 11/18 and that of Ki-67 was 14/18 in the interstitial cells and the positive expression of CD31 in the endothelial cells was 17/18.There were no significant differences between familial and sporadic CNS-HB in the positive expression of Inhibin-α,Ki-67 or CD31 (P＞0.05).Conclusions The pathogenesis of familial CNS-HB may be associated with not only VHL gene mutation but also other factors.Familial and sporadic CNS-HB may be similar in pathological features.

Objective To study the clinical efficacy of modified posterior occipital fusion in atlantooccipital and atlantoaxial dislocation in children and adolescents. Methods The clinical data of 11 children or adolescents with atlantooccipital and atlantoaxial dislocation, admitted to and accepted modified posterior occipital fusion in our hospital from November 2013 to March 2018, were retrospectively analyzed. Before and after the surgery, Japanese orthopedic association (JOA) scale was used to evaluate the cervical vertebral function of the patients, the atlanto-dens interval (ADI) was measured by CT images to evaluate the dislocation and reduction of joints, and the medulla bulbar cervical medulla angle (CMA) of the patients was measured by MR imaging to evaluate the degrees of spinal cord compression. Results The clinical symptoms of 11 patients improved in different degrees. No postoperative complications occurred. JOA scale scores after operation were significantly higher than those before operation (15.0±1.0 vs. 12.2±1.6). Significantly decreased of ADI and significantly increased CMA after operation were noted as compared with those before operation (P<0.05). Conclusion Modified posterior occipital fusion is safe and effective for treatment of atlantooccipital and atlantoaxial dislocation in children and adolescents.