Objective To investigate the effectiveness of gamma-knife radiotherapy combined with stent placement for the treatment of cancerous thrombus in inferior vena cava (IVC) in patients with hepatic carcinoma. Methods Stent placement was performed in 26 patients of hepatic carcinoma associated with cancerous thrombus in IVC,which was followed by gamma-knife radiotherapy for the treatment of thrombus. IVC angiography was reexamined at regular intervals to find out the patent situation and to measure the internal diameter of IVC. Results The internal diameter of IVC was increased in different degree after the treatment. After stent placement the internal diameter of IVC was increased by (0.842 ? 0.283) cm,while the internal diameter of IVC was increased by (1.523 ? 0.195) cm after gamma-knife radiotherapy. The internal diameter of IVC after gamma-knife radiotherapy was significantly greater than that before stent placement (P

Objective To master the various characteristics of EBCT and it's applications in clinic in depth. Methods Different scan modes were compared with each other. Results EBCT had the advantage of high speed in scanning and high resolving power of time without mechanical abrasion due to the using of electron beam. Conclusion EBCT is suitable for the examinations of cardiovascular system, and moving organs and uncooperative patients, and also for the application to CT fluoroscopy.

Quality assurance of EBCT images is especially important in clinic. Factors influencing the quality of images are so variable and complex that comprehensive consideration should be paid to them. The analyses and researches for such factors as surrounding background, machine's inherent property and scanning parameters are made separately.

Objective To verify the usefulness of the corresponding compensation techniques for MRI artifacts after analyzing their generation mechanism. Methods Different compensation techniques were used to eliminate relative artifacts from the angle of improving background,calibrating software and hardware,editing parameters or instructing patients in scanning the patient or phantom with 1.0TMR and 1.5TMR. Results Artifacts were controlled to different extents and the quality of most MR images were improved. Conclusion Most artifacts can be eliminated completely by the use of corresponding compensation techniques while some others only be reduced a little or shifted.

Objective To verify whether it is useful to apply the corresponding preventive measures for the radio frequency(RF) field artifacts in MR images by the research of their influencing factors.Methods Preventive measures were taken according to the factors producing RF field artifacts in MR images.Results Various RF field artifacts in MR images were reduced,shifted or even eliminated completely.Conclusion Most RF field artifacts in MR images can be controlled by the application of the relative preventive measures.

Objective To evaluate the application effect of workload statistic software.Methods According to the actual workflow of the hospital and concrete management index sign,the workload of statistics procedure was designed using Dephi7.0.Results "Comprehensive Management System in Medical Imaging Department" run stable and accurate.What's more,its functions greatly facilitated workload statistics.Conclusion The system plays an important role in excellent workflow,exaltation of work efficiency,reasonable allotment of manpower and material resources,etc.

Objective To evaluate the clinical value of fMRI software.Methods Patients were scanned with the corresponding fMRI software to observe the change of imaging signals in tissue's functional zone.Results The signals in the relative functional zone of tissues varied with their functions.Consulation fMRI software has great value in such clinical applications as tissue physiology,biochemistry and metabolism functions.

Cerebral ischemia accounts for 70%~80%. Magnetic resonance imaging (MRI) shows infarct focus efficiently, which plays an important role in the diagnosis of ultra-early stage of ischemia and the prediction of infarcts' change. This paper reviewed the recent advance in the effect of MRI on the diagnosis and prediction of cerebral ischemia.

OBJECTIVE:To provide references and suggestions for building and improving the R&D incentive policies for or-phan drugs in China. METHODS:The R&D incentive policies for orphan drugs in USA and the EU were compared in aspects of its legislative history,incentive measures and effects. And suggestions for improving related policies in China were put forward. RE-SULTS & CONCLUSIONS:The R&D incentive policies for orphan drugs in USA and the EU respectively started from Orphan Drug Act in USA(1983)and Orphan Drug Management Specification in the EU(1999),then formed relatively complete system by continuous improvement. The USA and the EU showed differences in its certification standard,procedure and specific incentives [R&D funding,tax deduction,fee reduction,additional incentives for micro and small and medium enterprises (SMEs),market exclusivity and special approval procedure],etc. In terms of fee reduction,for example,prescription application fee,production cost and drug confirmation fee were exempted in USA,while arrangement assist fee,initial and follow-up fee,checking fee before approval,initial listing type were reduced to a certain percentage in the EU. After developing incentive policies for orphan drugs, there is great increase in numbers of recognized qualifications and listing,SMEs have become new force in orphan drug R&D, R&D investment covers all types of diseases,orphan drug R&D are becoming the main direction of drug innovation and biotechnol-ogy development. China should determine the relevant legislation of R&D incentives for orphan drugs as soon as possible,set certi-fication and improve specific measures of R&D incentives for orphan drugs from multiple aspects,while strengthen the cooperation with other countries in qualification and R&D incentives.

Objective To investigate the effects of glutamine(Gln) and epidermal growth factor(EGF) on small intestinal repair in neonatal rats with necrotizing enterocolitis(NEC).Methods Forty neonatal rats of NEC model were divided into 5 groups:group A(control group),group B(NEC model),group C(NEC+Gln),group D(NEC+EGF+Gln).After NEC model of neonatal rats,all the neonatal rats were returned to their mothers.In the 4~(th) day,all the subjects were put to the death.Intestinal tissue located at the boundary of ileum and cecum was obtained to observe histological changes.Morphological changes were measured under a light microscope,and expression of proliferating cell nuclear antigen(PCNA) as an index of cell proliferation was observed using immunohistochemical staining and image analysis,expression of apoptosis was observed by TUNEL staining and image analysis.Results In group B,the histological lesions ranged was different,and was graded 3 score.In group C,D,the histological lesions ranged was graded 1 score.The number of(PCNA) in group B was lower than that in group A(P