BACKGROUND: The deficiency of perfect animal femoral head necrosis model limited its further investigation. OBJECTIVE: To verify the feasibility of establishing rabbit femoral head necrosis models using liquid nitrogen rsfdgeration method, and to provide a foundation for subsequent research. METHODS: A total of 20 adult, New Zealand, white rabbits were selected in the study. The round ligament of femur was not cut off and femoral head was not dislocated, and the exposed femoral head were quick frozen using cotton bud carrying liquid nitrogen for successive 25 times, with 10 s per time. The specimens were examined by gross anatomy, X-ray film, MRI and histological observation at day 3, 7 and weeks 2, 4, 6, and 8 after operation. RESULTS AND CONCLUSION: The histolOgical section showed that chondrocyte, osteccyts, and myelold tissues presented necrosis in freezing and periphery at 3days after model preparation, and the repair process appeared at 2weeks after operation. The articular surface of femoral heads appeared collapse at 4 weeks after operation, and these changes became obvious at 6 weeks. The femoral head presented ostecarthdtis-like disorder, with seriously collapsed articular surface at8 weeks, and the contour of femoral head changed in 2 animals. The results demonstrated that without hip dislocation, rabbit femoral head necrosis models can be established successfully using liquid nitrogen refrigeration method. This method is simple, feesible, with high succeed rate, which can be used in subsequent research.

Objective:To explore the application effect of the "combination of virtuality and actuality" practical teaching on Medical Imaging Equipment. Methods:The 2018 medical imaging technology students of Qiqihar Medical University were taken as the observation group, and the study adopted teaching method of "combination of virtuality and reality" in the practical teaching of Medical Imaging Equipment, including in-kind visit teaching (8 learning hours), experimental box circuit measurement teaching (20 learning hours) and virtual simulation teaching (16 learning hours). Besides, the 2017 medical imaging major students (control group) did not conduct virtual simulation teaching. The teaching effect and student achievement were compared between the two groups, and SPSS 17.0 was used to conduct t test and chi-square test. Results:There was significantly improvement in the practical performance of the students in the observation group compared with the control group ( t=6.44, P=0.007); the teaching satisfaction of the two groups was significantly improved ( χ2=5.25, P=0.022), and the teaching satisfaction degree was 100%. Conclusion:The teaching method of "combination of virtuality and reality" can effectively improve students' hands-on ability, strengthens their cognition of abstract principles, and solves the problems of equipment failure analysis, disassembly and installation of large-scale equipment that cannot be completed in physical teaching.

OBJECTIVETo compare the characteristics of esophageal gastric varices in portal hypertension patients with and without spontaneous shunts.

METHODSClinical data of 118 patients with esophageal gastric varices undergoing portal vein computed tomographic angiography (CTA) and gastroscopy between January 2012 and August 2015 was retrospectively reviewed.

RESULTSPortal vein CTA results showed that spleno-renal or gastro-renal shunts were detected in 24 out of 118 cases. The average portal vein diameters (PVD) of patients with and without spontaneous shunt were (12.48±2.79) mm and (13.58±3.46) mm, respectively (P>0.05). The average area of gastric veins in patients with spontaneous shunt was significantly larger than that of patients without shunt [294.00 (0.00~2400.00) mm2 vs. 26.00 (0.00~1620.00) mm2, respectively, (P<0.001]. Compared with patients without spontaneous shunt, the location of esophageal varices was lower and the degree was less serious in patients with spontaneous shunt (P<0.05). No matter with history of uppergastrointestinal bleeding, the average area of gastric veins in patients with spontaneous shunt was significantly larger than that of patients without shunt (P<0.05). For patients having no history of splenectomy, the average portal vein diameter (PVD) in those with spontaneous shunt was significantly smaller than that in those without shunt (P<0.05).

CONCLUSIONThe portal vein diameter of patients without splenectomy and with spontaneous shunts is shorter and their esophageal varices are less serious; the gastric veins are large and wriggly in patients with spontaneous shunts.

Angiography ; Esophageal and Gastric Varices ; physiopathology ; Gastroscopy ; Humans ; Hypertension, Portal ; physiopathology ; Portal Vein ; pathology ; Retrospective Studies ; Spleen ; Tomography, X-Ray Computed