Influencing factors of geometrical accuracy in magnetic resonance imaging for gamma knife radiosurgery / 中华放射医学与防护杂志

Objective To evaluate and improve the geometrical accuracy of the magnetic resonance imaging used for gamma knife radiosurgery localization. Methods Four common MRI scan programs were used in this study. The images were transferred to the Gamma Plan treatment planning system.Deviations between stereotactic coordinates based on MR images and real geometrical positions given by the construction of the phantom insert were evaluated for each study.The deviations were further investigated as a function of the spatial position of measured points in the investigated volume.Results The geometrical coordinate errors for axial and coronal images of the selected scan programs were all less than 1 mm.Optimal imaging procedure in terms of geometrical accuracy was observed using spin echo T1 and 3D FSPGR MRI sequences in the unit.Statistically significant differences were found in axial images amongSE T1,FSE T2,FRFSE Pd,FSPGR 3D sequences (F=1497.51,1873.63,2.87,3.00,P ＜0.05).The error increased along with the increase of the distance between node point and centricity.Conclusions The geometrical coordinate errors is related with the imaging program in M(il)l. Proper imaging programs and parameters should be selected according to the imageology character of patients' lesions when the radiosurgery is performed.

Increased Expression of EMMPRIN and VEGF in the Rat Brain after Gamma Irradiation

The extracellular matrix metalloproteinase inducer (EMMPRIN) has been known to play a key regulatory role in pathological angiogenesis. A elevated activation of vascular endothelial growth factor (VEGF) following radiation injury has been shown to mediate blood-brain barrier (BBB) breakdown. However, the roles of EMMPRIN and VEGF in radiation-induced brain injury after gamma knife surgery (GKS) are not clearly understood. In this study, we investigated EMMPRIN changes in a rat model of radiation injury following GKS and examined potential associations between EMMPRIN and VEGF expression. Adult male rats were subjected to cerebral radiation injury by GKS under anesthesia. We found that EMMPRIN and VEGF expression were markedly upregulated in the target area at 8-12 weeks after GKS compared with the control group by western blot, immunohistochemistry, and RT-PCR analysis. Immunofluorescent double staining demonstrated that EMMPRIN signals colocalized with caspase-3 and VEGF-positive cells. Our data also demonstrated that increased EMMPRIN expression was correlated with increased VEGF levels in a temporal manner. This is the first study to show that EMMPRIN and VEGF may play a role in radiation injuries of the central nervous system after GKS.

Determination of polysaccaride content in Radix Hedysari by HPLC / 中成药

AIM: To establish a method for determing polysaccaride content of Radix Hedysari(Hedysarum Polybotrys Hand-Mazz). METHODS: To determine content of Radix Hedysari polysaccaride by HPLC and ELSD. RESULTS: The composes of Radix Hedysari polysaccaride Ⅰ、Ⅱ、Ⅲ、Ⅳ are all Rhamnose、Arabinose、Xylose、Glucose、Galactose,the average content of polysaccharides is 25.34%、24.23%、15.08%、17.24%. CONCLUSION: The contents of Radix Hedysari polysaccaride in Radix Hedysari can be determined by HPLC.