Objective To analyse the CT,MRI features of pleomorphic xanthoastrocytoma and improve the diagnosis.Methods Imaging feature of pleomorphic xanthoastrocytoma of 26 cases confirmed by surgery and pathology were analyzed retrospectively.Distribution,size,shape,signal,dense,peritumor edema and invasion of adjacent structures of lesion were summarized.Results The locations of lesions included:temporosphenoid lobe (19 cases),frontal lobe (2 cases),the lateral and three ventricles in 1 case,occipital lobe (1 case),medulla oblongata (1 case),and cervical cord (1 case).The tumor size:maximum:82 mm × 40 mm × 70 mm,minimum:16 mm × 13 mm × 14 mm.Solid lesions (3 cases),solid lesions with necrosis (7 cases),solid and cystic lesions (16 cases),lesion with calcification (4 cases).The solid lesions of the tumors showed equal signal intensity or slightly low signal intensity on T1WI,and equal signal intensity or slightly high signal intensity on T2WI.The equidensite and high density on CT,peritumor edema degree:mild (2 cases),moderate (5 cases),severe (1 case).Conclusion The characteristic imaging features can help in the understanding and diagnosis of pleomorphic xanthoastrocytoma.

Objective To investigate the clinical efficacy of our self-designed sight used to guide thoracic vertebroplasty.Methods A retrospective analysis was conducted of the 52 patients (70 thoracic vertebrae) who had undergone percutaneous vertebroplasty (PVP) (n =36)or percataneous kyphoplasty (PKP) (n =34) of T1-T4 vertebral bodies at Department of Orthopaedics,The First Affiliated Hospital to Zhengzhou University form August 2012 to October 2013.The operation time,intraoperative bleeding,intraoperative radiation by C-arm roentgenography,and visual analogue scale (VAS) were compared between the patients whose surgery had been guided by our self-designed sight and those whose surgery had been not.Results All the patients were followed up for 18 to 36 months (average,22.3 months).Compared with those who had not used the sight,the patients who had used the sight incurred significantly shorter operation time (16.5 ± 3.2 min versus 26.5 ± 3.7 min),significantly less intraoperative bleeding (2.8 ± 1.3 mL versus 6.3 ± 1.7 mL) and significantly less radiation by C-arm roentgenography (5.6 ± 3.3 times versus 9.4 ± 3.1 times) (P ＜0.05).The VAS scores at postoperative 3 days and final follow-up were significantly decreased than the preoperative values in all the patients (P ＜ 0.05).There were no significant differences between the patients who had used the sight and those who had not in the the VAS scores at postoperative 3 days or final follow-up (P ＞ 0.05).Conclusions The upper thoracic PVP or PKP guided by our self-designed sight has theadvantages of short operation time,less intraoperative bleeding and less frequency of C-arm radiation.The sight is suitable for various vertebroplasties.

Objective To compare lateral orbital keyhole approach(LOK) with conventional keyhole approach including supraorbital keyhole approach (SOK) and pterional approach(PTK) for exposuring the sellar region and oper-ation ability, to provide theoretical and practical basis for the clinic. Methods From January, 2017 to Feburary, 2018, 15 cadaver head specimens of Chinese (30 sides) fixed by formalin were randomly divided into 3 groups, simu-lating SOK, LOK and PTK, application of frameless neuronavigation system, intersection of the posterior margin of the optic chiasma and the lamina terminalis served as the base point. Six different reference points were selected to radi-ate into the parasellar region of the skull base. The direction of the 2 adjacent reference points were connected to the base point to form a triangle. Six triangles constituted the sellar region to represent the total area. The supratentorial area, ipsilateral area, inferior area and contralateral area were calculated by stacking triangle. The comparison was made between groups. The Salma operation exposure scale was used to simulate the aneurysms of the common parts in the brain and the quantitative scores were performed. Results The total parasellar regions by SOK, LOK and PTK respectively were:(1641.6±295.6)mm2, (1782.3±294.6)mm2 and (1552.5±307.4)mm2. There was no statistical differ-ence(P>0.05); To compare the supratentorial region, SOK and LOK were both bigger than PTK ( P<0.05); To compare the ipsilateral and infratentorial area, LOK and PTK were both bigger than SOK respectively ( P<0.05);To compare the contralateral area, SOK, LOK and PTK were increased in turn (P<0.05). Salma operation exposure scale was used to get the scores:the score of SOK was 29.7 (39.08％), LOK was 37.0 (48.68％), and PTK was 36.1 (47.50％). Conclusion Anatomical analysis displayed that the 3 keyhole approaches showed different exposure of each part the parasellar re-gions, the LOK had a good exposure to the parasellar region and so as the higher maneuverability. But the clinical appli-cation should be comprehensive analysis, pay attention to specific lesions and make an appropriate choice. It has impor-tant clinical significance to improve the prognosis of patients.