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Objective To design a test phantom for clinical routine quality control of magnetic resonance imaging (MRI).Methods The commonly used phantom such as Magphan SMR170 and Victoreen 76-903 were used for experiments with the same parameters,and the test data of all the modules were compared.The advantages and disadvantages of all the modules were analyzed,and an optimization scheme was proposed accordingly.Results The phantom could be applied to the detection of high-image-quality MRI machine,and solved the problems in positioning,size matching and etc.Conclusion The new phantom meets the demand of magnetic resonance imaging clinical routine testing,and provides a certain reference for phantom optimization design.
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Objective To explore the development trend of military-civilian metering of medical equipment.Methods The foundation and conditions were analyzed for military-civilian metering of medical equipment,and the feasibility and necessity were discussed to execute military-civilian medical equipment metering after military innovation.Results The military-civilian metering of medical equipment was expounded from the aspects of organization,mechanism,personnel and etc.Conclution Military-civilian medical equipment metering contributes to rational allocation of national resources and enhancement of military metering.
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Objective To analyze the metrological verification parameters and methods for dual-energy X-ray absorptiometry (DEXA) to facilitate magnitude traceability.Methods DEXA's principle was discussed from the aspects of dual-energy X-ray absorption method and hardware structure.The method combining corresponding theory and specifications was used to describe the measurement accuracy and repeatability as well as the verification method and data processing for radiation protection performance parameters.Theoretical analysis was executed on corresponding parameters.Results Theoretical analysis was carried out on the metrological verification parameters of DEXA from the aspects of principle structure and measuring method.Conclusion It's of great significance for enhancing DEXA metrological verification to master the metrological verification parameters and methods.
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Objective To analyze the metrological verification parameters and methods for dual-energy X-ray absorptiometry (DEXA) to facilitate magnitude traceability.Methods DEXA's principle was discussed from the aspects of dual-energy X-ray absorption method and hardware structure.The method combining corresponding theory and specifications was used to describe the measurement accuracy and repeatability as well as the verification method and data processing for radiation protection performance parameters.Theoretical analysis was executed on corresponding parameters.Results Theoretical analysis was carried out on the metrological verification parameters of DEXA from the aspects of principle structure and measuring method.Conclusion It's of great significance for enhancing DEXA metrological verification to master the metrological verification parameters and methods.
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Objective To develop a simulation phantom for clinical detection of radiation intensity at the organs or tissue vulnerable to X-ray. Methods The organs or tissue vulnerable to X-ray radiation were explored to determine the region of interest of the radiation to the phantom. A mathematical model was established, and the technical characteristics of the equivalent materials of different tissues were studied. The existing ion chamber probes were compared on the technical performances, and the probe was selected with considerations on comprehensive factors. The phantom was gifted with two sizes of adult and child and designed based on the positions of sensitive organs. Practical trials were carried out to test the performances of the phantom. Results The phantom could be used to measure the radiation dose which was equivalent to the value of multiple human organs, and the desired requirements were fulfilled. Conclusion The phantom gains advantages in simulation fidelity, withdrawal of the probe and etc, and thus is worthy promoting practically.
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We developed and validated a method using high performance liquid chromatography ( HPLC ) coupled with electrospray ionization tandem mass spectrometry ( ESI_MS/MS ) to simultaneously quantify 11 urinary volatile organic compound ( VOC ) metabolites. The frozen urinary samples were unfrozen at room temperature and centrifuged to remove settled precipitate. 100 μL of the supernatant and 50 μL of internal standard were added and then diluted by 850μL of water so as to be analyzed by LC_MS/MS. The compounds were separated on a XSELECT HSS T3 column using acetonitrile as mobile phase A and 15 mmol/L ammonium acetate as mobile phase B at a flow rate of 250μL/min. The analytes were determined qualitatively and quantitatively under multi_reaction monitoring ( MRM) and negative polarity mode. The limits of detection ranged from 0 . 5-30 μg/L and the spiked recoveries of the analytes ranged from 89 . 8%-123 . 8% with RSDs of 3 . 1%-14 . 4%. This method was applied to 22 h urine samples collected from 16 smokers and 6 non_smokers. The results showed that the contents of the metabolites in smokerˊs urine were higher than those of nonsmokers, especially, smoking more than 25 cigarettes per day.