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OBJECTIVE: To analyze the results of inter-laboratory comparison among occupational hygiene laboratories. METHODS: A convenient sampling method was used. The laboratories participating in the inter-laboratory comparison organized by the Guangdong Occupational Health Test Center from 2013 to 2017 were selected as study subjects. The data of detection of organic compounds, metal element, inorganic non-metal element in workplace air, detection of metal element in biological materials, and detection of free silica in dust were analyzed. The results were statistically analyzed by four-point robust statistical technique. RESULTS: A total of 615 laboratories(times) participated in the comparison, and 2 785 items of sample detection results were submitted from 2013 to 2017.Among them, a total of 2 484 items were tested qualified and the sample test qualified rate was 89.2%. The test qualified rates of organics in workplace air, metals in workplace air, inorganic nonmetals in workplace air, metals in biological materials and free silica in dust were 91.1%, 92.0%, 86.6%, 80.4% and 85.0%, respectively. The sample test qualified rates of the laboratories in different regions from high to low were: the laboratories Pearl River Delta region in Guangdong Province, the laboratories in non-pearl river delta region in Guangdong Province and the laboratories outside of Guangdong Province were 91.6%, 87.2% and 72.6%(P<0.01), respectively. The sample test qualified rate of the public laboratories was higher than that of the private laboratories(90.3% vs 87.0%, P<0.05). CONCLUSION: The accuracy of the occupational hazard factor test in the participating laboratories needs to be improved. It is necessary to further strengthen the investment, supervision and management to non-pearl river delta region laboratories and private laboratories in Guangdong Province.
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OBJECTIVE: To investigate the individual external dose level of medical radiation staffs in Guangzhou City.METHODS: The medical radiation staffs of Guangzhou City who conducted individual dose monitoring at Guangdong Province Hospital Center for Occupational Diseases Prevention and Treatment from 2008 to 2014 were selected as study subjects by convenient sampling method.Their individual dosage monitoring data were analyzed.RESULTS: A total of 17 754 person-times were monitored in 7 years.The annual collective effective dose was 10 621.1 person·mSv and the median per capita annual effective dose was 0.21 mSv/a.The per capita annual effective dose in 2008-2012 showed an increasing trend each year( P < 0.05),peaked in 2012,and then decreased in 2013 and 2014( P < 0.05).The per capita annual effective dose of radiology staffs in level Ⅱ medical institutions was higher than that of level Ⅲ medical institutions,level Ⅰ medical institutions and those below level Ⅰ( P < 0.01).The per capita annual effective dose of radiation staffs in level Ⅲ medical institutions was higher than level Ⅰ medical institutions and those below level Ⅰ( P <0.01).The effective monitoring rates of radiation staffs monitored for 4 cycles every year increased with time from 2008 to 2014( P < 0.01).The effective monitoring rate increased with the hospital level( P < 0.01).The per capita annual effective dose of the staffs in radiological diagnosis department was lower than that of clinical nuclear medicine,radiotherapy and interventional radiology( P < 0.01).CONCLUSION: The radiation dose of medical radiation staffs in Guangzhou City was within the national standard limit.Protection should be focused on the the staffs in secondary hospitals,clinical nuclear medicine,radiotherapy and interventional radiology.
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Objective To analyse CT signs of giant cell tumor of bone.Methods CT appearances of 42 cases of giant cell tumor of bone were reviewed.All patients were pathological proven.Results (1)Two kinds of bone destruction were seen in all ases:expansive cystic destruction and osteolytic destruction.The anterior was predominantly.(2)Most of our patients haven't bone septations in their tumors (95.2%).(3)Bone crests were usually seen in our study(63.2%).(4)Complete or incomplete sclerotic borders existed in 44.7% of all cases.(5)The inner bone soft tissues were heterogeneously in most of the patients.Fluid-fluid level can be seen in 5 cases (11.9%).(6)The outer-bone soft tissue masses were demonstrated in the majority cases with discontinuous bone shell.Conclusion CT may deepen our understanding and add imaging signs about giant cell tumor of bone;Which can enhance our diagnostic and differential diagnostic capability.
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Objective To study the imageological findings and the evolution of pulmonary alveolar microlithiasis(PAM). Methods The clinical and imageological information of 3 siblings suffering from PAM were collected, and their imageological findings and changes in follow-up plain radiographs were analyzed retrospectively. Results On chest radiographs, the typical “sandstorm” pattern was shown in all 3 cases. The severity and extent of microliths and interstitial fibrosis were increased with age and clinical course by comparing with the radiographs 24 years ago. On conventional CT, bilateral diffuse micronodules in parenchyma were demonstrated with pulmonary window in 3 cases, concentrating in the subpleural zones of middle and lower lung fields and the areas around bronchovascular bundles. All were associated with various degrees of fibrosis. The nodules and calcifications were visible in both lungs with mediastinal window, forming so-called flame sign and white line sign in the concentrated areas. The extents and degrees of the microliths, small cysts and interstitial fibrosis were revealed more clearly and truly on HRCT. MRI showed diffusely increased signal intensity on T 1WI and lower signal intensity on T 2WI in both lung fields. Conclusion The chest radiograph was still an initial modality in detecting the disease. CT could comprehensively reveal the pathological status of the PAM and played a decisive role in the diagnosis and differential diagnosis. MRI had only limited value in evaluating the condition.