It belongs to the ethics that depending to much on high-tech instruments in diagnoses of diseases and overlooking medical examination and clinical history. In clinic educations, we should train medicos to envisage the effects of high-tech instruments in diagnoses of diseases, and strengthen their feeling of responsibility and training of clinic basic shills.

Objective To evaluate the helical CT diagnostic value of primary retroperitoneal neoplasm(PRN). Methods 32 cases of PRN confirmed by operation and pathology were retrospectively analyzed. Plain and enhanced CT scan were perfomed in 28 cases,and only 4 cases underwent plain CT scans. Results Of 32 cases,15 were benign tumor and 17 cases were malignant tumor.Among them ,16 cases were mesenchymal tissue-origin(11 cases were malignant neoplasm), 10 cases were nervous tissue-origin(3 cases were malignant neoplasm),3 cases were rudimental embryonal tissue-origin(all benign), and the source of unknown-origin were 3cases(all malignant neoplasm).To be correctly localized was 28 cases(87.5%) and correctly qualitative diagnosis of the tumor was 20 cases (62.5%) by CT before operation. Conclusion PRNs have many typies, helical CT provides informations in both position and characteristics before operation.

Objective To explore the value of helical computed tomography (CT) in differential diagnosis of xanthogranulomatous cholecystitis (XGC) and wall-thicked gallbladder cancer (GBC).Methods The CT signs of 18 XGCs and 20 wall-thicked GBCs were retrospectively analyzed.The maximum thickness of gallbladder wall, intramural hypoattenuated nodules, mucosal line of gallbladder inner wall,patterns of enhancement of thickened wall,whether combined with stones,the pericholecystic adjacent liver tissue involvement and biliary tract obstruction were observed.Measurement data were analyzed by independent sample t test and count date were analyzed by Fisher precisely the probability method.Results The mean maximum thickness of the gallbladder wall of XGC and wall-thicked GBC was (22.11±10.19) mm and (20.55±7.94) mm respectively,and there was no statistical significance (t=0.530,P=0.600).Eighteen cases of XGC and five cases of wall- thicked GBC patients were with intramural hypoattenuated nodules (Fisher precisely the probability method,P＜0.01 ),14 cases of XGC and six cases of GBC were with integrated mucosal line (Fisher precisely the probability method,P =0.004 ),three cases of XGC and 12 cases of GBC were with biliary tract obstruction (Fisher precisely the probability method,P=0.009).There was no statistical significance in the CT signs of the range of wall thickness,patterns of enhancement and enhanced degree of thickened wall,adjacent liver tissue involvement, lymphadenopathy, combined with gallbladder or bile duct stone between XGC and wall-thicked GBC patients (Fisher precisely the probability method,all P ＞ 0.05).Conclusions The thickened gallbladder wall with intramural hypoattenuated nodules and integrated gallbladder inner wall mucosal line were characteristic signs for diagnosing XGC.Helical CT scanning can provide evidence for differential diagnosis in XGC and wall- thicked GBC.

The investigation of environmental radioactivity level is an important basic work of ecological environment protection. It can provide basic data and scientific basis for the evaluation of radioactive environment quality and the formulation of radiation safety regulations and standards. Based on many years of practical experience of environmental radioactivity level investigation, combined with relevant regulations and standards, this paper summarizes the common investigation methods in the investigation and research of environmental radioactivity level at home and abroad, summarizes a set of environmental radioactivity level investigation scheme with strong applicability, and gives detailed suggestions on the ideas, methods, technical routes and other key points of the investigation scheme. The research results of this paper can provide a reference for the preparation of environmental radioactive level investigation scheme.