Objective To discuss the construction and application of computer system in the radiology department of medium and small hospitals.Methods Through the local area network,the self-invented Radiological Information System(RIS) was linked to the Hospital Information System(HIS) and Wandong DR equipment software in coordination with the Neusoft CT software and the digital stomach and intestines software.Results A simple extraordinary and practical radiological information system was established,which possessed functions of PACS.Conclusion The management level in radiology department is enhanced and the working efficiency is increased.

Objective To establish an accuracy test method for MDCT dose assessment based on information in DICOM images.Methods The type of MDCT studied in this paper was widely used in clinical practice.A software package developed by java language was used to automatically read doserelated information from DICOM files of MDCT.The CTDIvol and DLP of each pectoral or abdominal scan was calculated based on these information and the basic scan parameters such as collimation,mAs and pitch.The calculated values were compared with the displayed values.Results For pectoral scans,the difference between the calculated and displayed values was between-2％-8％ for CTDIvol,and-2％-5％ for DLP.For abdominal scan,the difference between the calculated and displayed values was 0-2％ for CTDIvol,and-2％-3％ for DLP.Conclusions This method is useful for MDCT dose assessment and is worth disseminating its application for general use.

Objective To measure the body surface dose under different confinations of additional filters,tube voltage and tube current and discuss the lowest amount of different additional filters,tube voltage and tube current combination for crib side X-ray radiation dose while the quality of the image is guaranteed.Methods Japan Shimadzu wireless tablet mobile DR machine and Dutch Artinis CDRAD 2.0 phantom were used.The tube voltage and tube current for children's crib side X-ray normal work were 50 kV and 1.40 mAs to get the image quality figure inverse (IQFInv),respectively.Totally four filter combinations of 1 mm A1,2 mm A1,1+2 mm A1 and 0.3 mm Cu were added to the opening of collimator system by mobile DR machine.Phantom was shot by respectively combination of 50,66,83 and 100 kV tube voltages and different tube currents.All images to get the IQFInv value,Pearson correlation and regression analysis of the influence of tube voltage and current on IQFInv value were analyzed.The IQFInv value of the additional filter corresponds to the image quality of normal work.The combination of the additional filter with the tube voltage and the tube current was also found.Swedish RTI Barracuda diagnostic level dosimeter was used to measure the entrance surface dose of these combinations after filtration,20 times for each group.Results Comparisons among different filters,tube voltage and tube current combination with quality of daily work images:the tube voltage was positively correlated with IQFInv value in the test range(r=0.49,P＜0.05),and tube current was positively correlated with IQFInv value (r=0.36,P＜0.05).As the additional filters increase,it required greater tube current to acquire the desired value of images.Meanwhile,greater additional filters would increase the difference of IQFInv of tube voltage at each level.Comparisons among different filters,tube voltage and tube current combination with daily shooting dose,and after using additional filters,entrance surface dose changed from (30.58±0.21)to (10.49±0.09) μGy.There is a significant difference between each group (t=-15.306-514.585,P＜0.05).All additional filters effectively reduced entrance surface dose.Meanwhile,as the filter and tube voltage increased,entrance surface dose showed a more significant reduction.However,when the tube voltage exceeded 83 kV,all entrance surface dose of additional filters showed an increasing trend.Conclusions Additional filter is an effective method to reduce the crib side X-ray entrance surface dose.Under the premise of ensuring image quality,additional filter with high atomic number and second high kilovolt tube voltage with paired tube current is the best condition for crib side X-ray.

Objective: To study the the application characteristics of paediatric CT examination by investigating four main children′s hospital of Shanghai. Methods: All the CT scan cases of paediatric patients in this work were obtained from the radiology information system (RIS) database in four hospitals between 2011 and 2014. The distribution of using CT scans was analysed according to the age, gender, anatomical regions and the duplicated cases of the patient, then estimated the paediatric CT scan rates of four hospitals in Shanghai. Results: Retrospective review of RIS showed 249 350 CT examinations from 175 672 young patients were performed between 2011 and 2014 in the surveyed hospitals. More males (62%) were scanned than females (38%). The majority of children receiving the examinations were 1 to 5 years old, which amounted to 40.3% in all. Cardiac CT accounted for 14.5% among all children of ≤1 year old CTs and accounted for 63.0% among all cardiac CT scans. There were 33 634 (19.1%) individuals who had received 2 or more CT scans during the four years. The estimated paediatric CT scan frequencies of four hospitals in Shanghai from 2011 to 2014 were 37.9 examinations per 1 000 population in 2011, 43.3 examinations per 1 000 population in 2012, 43.3 examinations per 1 000 population in 2013 and 39.0 examinations per 1 000 population in 2014. Conclusions The CT scan frequencies of four hospitals in children and young adults was almost keeping stable in Shanghai.