Objective:To construct a safe operation management path based on work chain and extension matter-element model,and to explore its application effect in clinical management of magnetic resonance imaging(MRI)equipment.Methods:The safety risk evaluation indicators was developed from the perspective of MRI equipment work chain at the levels of personnel,equipment,environment and system.The rating of safety characteristic indicators of equipment was carried out and risk control management strategy was formulated by adopting extensible matter element model.The MRI equipment in clinical use in the Imaging Department of Shucheng People's Hospital from January 2019 to December 2021 was selected,and the standard process management mode(referred to as standard process mode)and risk assessment control mode(referred to as risk control mode)were adopted respectively for equipment operation management.The safety risk event control rate,safety operation management standardization and professional capability of staff of MRI equipment under two different management modes were compared.Results:Among 62 safety risk events of MRI equipment managed by risk control mode,the control rates of extremely dangerous,highly dangerous and significant dangerous events were 1.61%(1/62),4.84%(3/62)and 8.06%(5/62),respectively,which were lower than those of the standard process mode,the difference was statistically significant(x2=5.613,4.567,9.241,P<0.05).Among 480 cases of safety operation inspection carried out by risk control mode management,the standardization of patient reception,equipment use,operating environment and management system were 96.25%(462/480),98.96%(475/480),99.17%(476/480)and 97.50%(468/480),respectively,which were higher than those of the standard process mode,the difference was statistically significant(x2=18.631,17.563,7.353,8.789,P<0.05).The annual assessment scores of MRI technicians,nurses and medical engineering engineers of the imaging department adopting risk control mode were(91.87±4.56)points,(94.54±3.27)points and(91.45±4.95)points,respectively,which were higher than those of the standard process mode,the difference was statistically significant(t=3.291,4.277,4.292,P<0.05).Conclusion:The risk control management mode based on work chain and extension matter-element model can comprehensively explore the factors affecting the safe operation of MRI equipment,effectively control the incidence of high-risk events,improve the quality of clinical operation and operation management of MRI equipment.

Objective: To observe the manifestations of terminal ileitis on gemstone energy spectrum CT imaging (GSI) and its diagnostic efficacy compared conventional CT enterography (CTE), so as to evaluate the diagnosis value of GSI for terminal ileitis. Methods: Data of 120 patients with suspected terminal ileum diseases were retrospectively analyzed, including 115 cases of pathologically proved diseases (72 cases of terminal ileum enteritis, 6 cases of ileum polyps or tumorlike lesions, 30 cases of ileum Crohn's disease and 7 cases of ileum tuberculosis) and 5 cases without obvious abnormality. Among them 70 patients received conventional CTE (CTE group) and 50 received GSI (GSI group). Imaging characteristics of terminal ileitis were observed and compared between 2 groups. The consistency of the results of 2 methods for detecting terminal ileitis with pathological results were analyzed, and their sensitivities and specificities were compared. ROC curves of 2 methods for detecting terminal ileitis were drawn, and their relative diagnostic efficacy were analyzed. Results: Compared with conventional CTE, the lesions were clearer on low keV single energy imaging. The energy spectrum curve and iodide maps clearly identified the lesion's wall, normal wall, the fluid in intestinal cavity and the adjacent fat tissue. The iodine concentration of terminal ileitis at the arterial and venous phase was (10.90±0.55)μg/cm3 and (14.33±0.75)μg/cm3, respectively. Conventional CTE showed poor, while GSI showed high consistency with the pathological results for detecting terminal ileitis (Kappa=0.35, 0.72, P=0.16, <0.01). The sensitivity and specificity of GSI (86.21%, 85.71%) were bith higher than those of conventional CTE (65.12%, 51.85%, χ2=3.97, 6.10, both P<0.05). The AUC of GSI (0.86) was higher than that of conventional CTE (0.57, Z=2.42, P=0.02). Conclusion: GSI could clearly show lesions of terminal ileitis, therefore having high diagnostic efficacy for detecting terminal ileitis.