Objective To explore and establish a technical pathway for size-specific dose estimate (SSDE) in pediatric CT patients of different age groups based on structured dose files and DICOM files, and to provide an effective method for precise monitoring of medical radiation exposure in pediatric CT scans. Methods Structured radiation dose reports (SR files) for pediatric patients aged 15 and under, who underwent CT scans between January and December 2023, were exported from the hospital information system. Scanning parameters and dose information were extracted using specialized software, and SSDE was calculated based on the patient body size parameters. The data were grouped by age (0- < 1 year, 1- < 5 years, 5- < 10 years, and 10-15 years) for statistical analysis. Results From January to December 2023, a total of 2706 pediatric CT scans were performed at the hospital, including 385 (14.23%) head scans, 1990 (73.54%) chest scans, 143 (5.28%) abdominal scans, 112 (4.14%) limb scans, and 76 (2.81%) other scans. The typical volume CT dose index (CTDI_vol) for head CT in the age groups of 0- < 1 year, 1- < 5 years, 5- < 10 years, and 10-15 years were 36.21, 35.29, 37.27, and 41.18 mGy, respectively; the corresponding SSDE values were 41.27, 32.82, 30.56, and 28.41 mGy, respectively. For chest CT scans, the typical CTDI_vol for the age groups of 1- < 5 years, 5- < 10 years, and 10-15 years were 1.91, 2.11, and 2.51 mGy, respectively; the corresponding SSDE values were 2.36, 2.21, and 3.50 mGy, respectively. For abdominal CT scans, the typical CTDI_vol for the age groups of 1- < 5 years, 5- < 10 years, and 10-15 years were 3.94, 4.33, and 6.26 mGy, respectively; the corresponding SSDE values were 5.77, 7.10, and 9.79 mGy, respectively. Conclusion This study developed a technical pathway to estimate the medical radiation doses of pediatric CT patients of different ages based on structured dose files and DICOM files. The feasibility of this approach was validated using data collected over a one-year period.

Objective To investigate the basic situation of nuclear medicine diagnostic and treatment institutions in Shanghai, understand the development level and distribution characteristics of nuclear medicine in Shanghai, and assess the current status of nuclear medicine development in Shanghai. Methods Using questionnaires, on-site verification, and retrieval of information system records, a survey was carried out on nuclear medicine department staff, equipment, and personal radiation exposure levels of workers in Shanghai. Results As of December 2023, there were 48 nuclear medicine diagnostic and treatment institutions in Shanghai, including 32 (66.7%) tertiary hospitals. Of these, 24 (50%) hospitals performed ¹³¹I therapy, and 9 (18.8%) hospitals conducted ¹³¹I treatment for thyroid cancer. There were 681 nuclear medicine radiation workers, with an average annual effective dose from external radiation of 0.54 mSv. There were 137 pieces of nuclear medicine equipment, including 56 SPECT/CT, 42 PET/CT, 8 PET/MRI, 25 thyroid function meters, and 6 cyclotrons. In 2023, the total radioactivity of radionuclides used in Shanghai was 1.2 × 10⁸ MBq, with 3.4 × 10⁷ MBq of ¹⁸F, 7.4 × 10⁷ MBq of ^99mTc, and 1.2 × 10⁷ MBq of ¹³¹I. The total annual number of nuclear medicine diagnostic and treatment procedures performed was 247 826 and the application frequency was 10.0 procedures per thousand population. Conclusion Clinical nuclear medicine in Shanghai has developed rapidly, achieving the Level I healthcare standard as defined in the UNSCEAR 2008 report. Enhancing occupational protection for radiation workers is a critical issue that requires particular attention in the next phase of development.

Background::Acute pulmonary embolism (APE) is a fatal cardiovascular disease, yet missed diagnosis and misdiagnosis often occur due to non-specific symptoms and signs. A simple, objective technique will help clinicians make a quick and precise diagnosis. In population studies, machine learning (ML) plays a critical role in characterizing cardiovascular risks, predicting outcomes, and identifying biomarkers. This work sought to develop an ML model for helping APE diagnosis and compare it against current clinical probability assessment models.Methods::This is a single-center retrospective study. Patients with suspected APE were continuously enrolled and randomly divided into two groups including training and testing sets. A total of 8 ML models, including random forest (RF), Na?ve Bayes, decision tree, K-nearest neighbors, logistic regression, multi-layer perceptron, support vector machine, and gradient boosting decision tree were developed based on the training set to diagnose APE. Thereafter, the model with the best diagnostic performance was selected and evaluated against the current clinical assessment strategies, including the Wells score, revised Geneva score, and Years algorithm. Eventually, the ML model was internally validated to assess the diagnostic performance using receiver operating characteristic (ROC) analysis.Results::The ML models were constructed using eight clinical features, including D-dimer, cardiac troponin T (cTNT), arterial oxygen saturation, heart rate, chest pain, lower limb pain, hemoptysis, and chronic heart failure. Among eight ML models, the RF model achieved the best performance with the highest area under the curve (AUC) (AUC = 0.774). Compared to the current clinical assessment strategies, the RF model outperformed the Wells score ( P = 0.030) and was not inferior to any other clinical probability assessment strategy. The AUC of the RF model for diagnosing APE onset in internal validation set was 0.726. Conclusions::Based on RF algorithm, a novel prediction model was finally constructed for APE diagnosis. When compared to the current clinical assessment strategies, the RF model achieved better diagnostic efficacy and accuracy. Therefore, the ML algorithm can be a useful tool in assisting with the diagnosis of APE.

Objective:To understand the radiation protecton awareness of clinical staff for patients, and to provide strategies and suggestions for promoting the justification of medical exposure.Methods:From June to September 2023, 1 430 physicians or technicians from 10 tertiary hospitals, 9 secondary hospitals and 8 primary hospitals in Shanghai were selected by multi-stage stratified random sampling method to conduct a questionnaire survey about radiation-related cognition through a combination of offline and online survey. The contents of the questionnaire included the characteristics of the respondents, the training of radiation protection, the self-awareness of patients on radiation protection, the actual cognition of the basic knowledge of ionizing radiation, the cognition of the dose caused by different types of the radiological examinations, and the ways to access knowledge of ionizing radiation. SPSS software was used for statistical analysis.Results:A total of 1 229 valid questionnaires were received, of which 82.10% respondents belonged to the clinical department and 17.90% belonged to the radiology department. 58.37% of the respondents in clinical department have received radiation-related training, and 98.64% in radiology department have done so. The overall mastery of radiation protection-related knowledge in radiology department was better than in clinical department, and the difference was statistically significant ( χ2=39.58, P<0.05). Most of the respondents tended to underestimate the radiation dose to patients from CT scans, and the proportion of the respondents who underestimated the CT doses to different sites was all greater than 45%. Logistic regression analysis showed that the contributing factors affecting radiation protection cognition are a combination of technical titles, radiation protection training to a varing degree, the level of medical institutions and their majors (95% CI of the OR values did not include 1, χ2=5.66-28.26, P<0.05). Conclusions:Most clinical staff have realized the importance of controlling the radiation dose in radiological examinations, but there is less understanding of the dose magnitude caused by different radiological examinations. Education and training are the best way to improve the awareness of ionizing radiation. Radiation protection training should be integrated into general medical education or standardized training for physicians.

Background The monitoring of external radiation individual doses for radiation workers is a statutory task and serves as an important basis for the diagnosis of occupational diseases in this occupational group. Ensuring the accuracy and reliability of monitoring data is crucial for safeguarding the health of radiation workers. Objective To evaluate and compare the capabilities and levels of external radiation individual dose monitoring conducted by radiation hygiene service institutions in Shanghai, to standardize relevant workflows, and to improve the accuracy and reliability of the monitoring service. Methods From 2021 to 2023, annual intercomparisons of external radiation individual dose monitoring capabilities were organized for radiation hygiene service institutions in Shanghai. The study subjects were 19 to 21 radiation hygiene service institutions registered in Shanghai for each year and they all participated in the intercomparisons. The monitoring subjects included 16 district-level centers for disease control and prevention (CDCs) and 13 third-party testing agencies. Monitoring capabilities were analyzed based on single-group performance, comprehensive performance, and Q-value. In the intercomparison, a thermoluminescent dosimetry system was used to perform irradiation tests on thermoluminescence dosimeter [made of lithium fluoride (magnesium, copper, phosphorus), LiF (Mg, Cu, P)], and monitoring data for X-rays and γ-rays at different doses and radiation conditions were analyzed following a standard procedure specified by GBZ 207−2016. Statistical methods included t-test and Kolmogorov-Smirnov test, with statistical significance set at P<0.05. Results From 2021 to 2023, the number of participating institutions was 19, 21, and 19, respectively, with an overall pass rate of 94.9% (56/59). Two institutions failed in 2022 and one in 2023. The number of institutions meeting the excellent standard in single-group and comprehensive performance was 9, 12, and 13, respectively, and the number of institutions ultimately rated as excellent was 3, 7, and 8,respectively, with an overall excellence rate of 30.5% (18/59) and an excellence conversion rate of 52.9%. The pass rates for single-group and comprehensive performance were both 98.3%. The number of groups with negative deviation was 1.86 times that of groups with positive deviation for X-rays, and 1.10 times for γ-rays. For X-rays, there was a statistically significant deviation between doses of less than 1.0 mSv and more than 1.0 mSv (P=0.01), while there was no significant difference in the single-group performance deviation between X-rays and γ-rays at the same dose. There was a statistically significant difference between the reported and reference values for X-rays in 2021 and 2022 (P<0.05), but no significant difference in 2023 (P>0.05); there was no significant difference between the reported and reference values for γ-rays over the three years (P>0.05). Conclusion Over the past three years, the external radiation individual dose monitoring capability intercomparison results of radiation hygiene service institutions in Shanghai have shown that the pass rate remains at a high level, with the excellence rate increasing year by year. However, some institutions still need to improve their monitoring capabilities, and further cooperation among institutions and training for technical staff are needed to enhance the capabilities and standardization of external radiation individual dose monitoring in Shanghai.

ObjectiveThe purpose was to understand the background level of environmental radioactivity in the surrounding area of Qinshan Nuclear Power Plant and accumulate historical monitoring data of radioactivity in the environment， in order to detect and deal with radioactive risk in water sources earlier. MethodsAccording to the requirements of the "Shanghai environmental radioactivity background monitoring plan"， the area 1 closest to the Qinshan Nuclear Power Plant was selected as the monitoring point， and the area 2 far from the nuclear power plant was selected as the blank control point. Considering the seasonal characteristics of high water， low water， and normal water periods， the establishment of sampling points， and population density and other comprehensive factors， a model of sampling from the disease control centers in these two regions was established， with the supervision and quality control by Shanghai disease control center. The water samples were collected once a quarter， with a sampling volume of 5 L each time， and the samples were sent to Shanghai Municipal Center for Disease Control and Prevention for processing and measurement. Since 2012， water samples from the two sources have been collected for more than ten years for the total α and total β monitoring of radioactive levels. Results2012‒2022 Area 1 total α radioactivity， total β radioactivity concentration ranges were 1.83×10^-2‒3.93 ×10^-2 Bq·L^-1 and 6.05×10^-2‒23.73 ×10^-2 Bq·L^-1， respectively. Total α radioactivity and total β radioactivity concentration ranges in Area 2 were 1.63×10^-2‒4.46 ×10^-2 Bq·L^-1， and 9.60×10^-2‒25.33 ×10^-2 Bq·L^-1，respectively. ConclusionThe radioactive levels in the source water of Area 1 and Area 2 are within the normal background range， which meets the requirements of the "Standard test methods for drinking water - radioactive indicators" （GB/T 5750.13‒2006）.

ObjectiveTo analyze the individual monitoring results of the radiation workers in Shanghai’s Jing’an District from 2017 to 2023, to assess the occupational protection status as well as to offer scientific references for enhancing occupational health and radiation safety, and to provide support for health education initiatives targeting radiation workers. MethodsRadiation workers from several medical institutions in Jing’an District from 2017 to 2023 were selected as the subjects for this study. The individual dose of occupational external radiation exposure was monitored by using thermoluminescence dosimeters. Continuous data of seven years were statistically analyzed using SPSS 20.0. ResultsFrom 2017 to 2023, the annual collective effective dose for radiation workers in Jing’an District was 329.53 person·mSv, with an average individual annual effective dose of 0.17 mSv, and the median individual annual effective dose was 0.12 mSv. There were statistically significant differences in the individual annual effective doses across different years (H=277.131, P<0.05). The individual doses varied significantly among different levels of medical institutions (H=46.097, P<0.05), with tertiary institutions having the lowest median individual dose of 0.09 mSv, which was significantly lower than those at primary, secondary, and ungraded institutions (P<0.05). The median annual effective dose in males was lower than that in females, showing a statistically significant difference (Z=-3.438, P<0.05). There were significant differences in the individual annual effective doses among different occupational categories (H=150.727, P<0.05), with nuclear medicine workers experiencing the highest median annual dose of 0.56 mSv. ConclusionFrom 2017 to 2023, the individual dose of radiation workers in medical institutions in Jing’an District of Shanghai remained at a low level, reflecting the effective measures of radiation protection facilities in workplaces in Jing’an District, but particular attention should be given to radiological workers in nuclear medicine and workers in primary medical institutions.

Objective To investigate the quality control and protection level of medical electron linear accelerators in Shanghai, China. Methods The startified random sampling method was used to cover tertiary, secondary and ungraded hospitals, and a total of 30 medical electron linear accelerators in 15 hospitals were tested for quality control and protection level according to relevant standards. Results Five medical electron linear accelerators failed the quality control test, with an overall inspection pass rate of 83.3% and a re-inspection pass rate of 100%. The pass rate of flatness of square X-ray irradiation field (5 cm × 5 cm)-(30 cm × 30 cm) was 83.3%, the pass rate of symmetry of square X-ray irradiation field was 96.7%, and other indices were qualified. All medical electron linear accelerator rooms passed the protection test. Conclusion The protection of medical electron linear accelerator rooms in Shanghai meets the requirements of national standards, and some indices do not meet the requirements of national standards in the preliminary inspection. The quality control of medical electron linear accelerators should be further strengthened to ensure the treatment effect of patients.

Background Based on numerous epidemiological studies, radionuclide ¹³¹I can result in thyroid disease. Objective To study the contamination level of thyroid ¹³¹I in ¹³¹I treatment associated radiation workers in nuclear medicine departments in Shanghai. Methods Based on a general survey on basic situation of nuclear medicine in Shanghai, the level of internal exposure of radiation workers involved in ¹³¹I treatment was assessed with questionnaires and on-site monitoring. A portable γ spectrometer was used for on-site detection, the intake and annual effective dose were estimated according to the measurement results. Physical examination reports were collected for radionuclide positive workers, and chromosome testing was performed. Results There were 579 nuclear medicine workers and 175 were engaged in ¹³¹I treatment in Shanghai. ¹³¹I was detected in thyroid of 18 workers, with a detection rate of 10.3%. Among them, the detection rates of thyroid ¹³¹I in nurses and cleaners were 23% and 25% respectively. The mean measured activity of thyroid ¹³¹I was 306.1 Bq and the maximum measured activity was 3716.9 Bq (nurse). The maximum intake was estimated at 37544 Bq and the median was 786.4 Bq. The average annual committed effective dose was 1.22 mSv and the maximum value was 14.87mSv. The chromosomal aberration rates of all detected workers were negative, and all blood indicators were normal except one with low hemoglobin. Conclusion The annual dose of nuclear medical staff engaged in ¹³¹I treatment does not exceed the national standard limit, but the internal exposure of nurses and cleaners should not be ignored. On the basis of strengthening protection and decontamination, routine internal exposure monitoring should be carried out.

Objective:To investigate clinical effects of anterolateral thigh flap with blood supply source of medial femoral perforator in repairing the wounds on extremities.Methods:A retrospective observational study was conducted. From October 2018 to June 2021, Suzhou Ruihua Orthopedic Hospital admitted 12 patients (11 males and 1 female, aged 24-64 years) who met the inclusion criteria, and did not have the lateral circumflex femoral artery during anterolateral thigh flap resection, or changed to medial femoral perforator as a source of blood supply due to small perforator to repair the wound with flap transplantation. The wounds were on the upper limbs in 7 cases and on the lower limbs in 5 cases. The wound area after debridement was 8.0 cm×5.0 cm-24.0 cm×6.5 cm, and the applied flap area was 9 cm×6 cm-25 cm×7 cm. During transplantation, the perforating branch or source artery of the flap was anastomosed end to end with the vascular pedicle of the recipient area. Subcutaneous beauty suture was performed on all the donor wounds. After operation, the survival of the flap and vascular crisis were observed; and the wound healing at the donor site was observed. During follow-up, the texture of the flap and complications at the donor site were observed. At the last follow-up, the effect of flap repair was evaluated by using the modified self-made comprehensive efficacy rating table.Results:After operation, all the flaps of patients survived without vascular crisis; the wounds in the donor site healed smoothly. During follow-up of 6 to 26 months, the flaps had good texture; only linear scars remained in the donor area without scar contracture, pain or other discomfort. At the last follow-up, the total score of flap repair effect of 12 patients was 75-95, with an average of 87, of which 5 cases were rated as excellent, 6 cases as good, and 1 case as fair, and the proportion of excellent and good patients was 11/12.Conclusions:The application of anterolateral thigh flap with blood supply from the medial femoral perforator to repair wounds on extremities is an alternative method for the vascular variations such as no descending branch, oblique branch, or small perforator of the lateral circumflex femoral artery during the resection of the anterolateral thigh flap. This operation has the advantages of simple operation, small trauma, and others, which effectively ensures the smooth operation.