Résumé
The Monte Carlo N-Particle (MCNP) is often used to calculate the radiation dose during computed tomography (CT) scans. However, the physical calculation process of the model is complicated, the input file structure of the program is complex, and the three-dimensional (3D) display of the geometric model is not supported, so that the researchers cannot establish an accurate CT radiation system model, which affects the accuracy of the dose calculation results. Aiming at these two problems, this study designed a software that visualized CT modeling and automatically generated input files. In terms of model calculation, the theoretical basis was based on the integration of CT modeling improvement schemes of major researchers. For 3D model visualization, LabVIEW was used as the new development platform, constructive solid geometry (CSG) was used as the algorithm principle, and the introduction of editing of MCNP input files was used to visualize CT geometry modeling. Compared with a CT model established by a recent study, the root mean square error between the results simulated by this visual CT modeling software and the actual measurement was smaller. In conclusion, the proposed CT visualization modeling software can not only help researchers to obtain an accurate CT radiation system model, but also provide a new research idea for the geometric modeling visualization method of MCNP.
Sujets)
Dose de rayonnement , Conception de logiciel , Tomodensitométrie/méthodes , Logiciel , Algorithmes , Fantômes en imagerie , Méthode de Monte CarloRésumé
In recent years, photon-counting computed tomography (PCD-CT) based on photon-counting detectors (PCDs) has become increasingly utilized in clinical practice. Compared with conventional CT, PCD-CT has the potential to achieve micron-level spatial resolution, lower radiation dose, negligible electronic noise, multi-energy imaging, and material identification, etc. This advancement facilitates the promotion of ultra-low dose scans in clinical scenarios, potentially detecting minimal and hidden lesions, thus significantly improving image quality. However, the current state of the art is limited and issues such as charge sharing, pulse pileup, K-escape and count rate drift remain unresolved. These issues could lead to a decrease in image resolution and energy resolution, while an increasing in image noise and ring artifact and so on. This article systematically reviewed the physical principles of PCD-CT, and outlined the structural differences between PCDs and energy integration detectors (EIDs), and the current challenges in the development of PCD-CT. In addition, the advantages and disadvantages of three detector materials were analysed. Then, the clinical benefits of PCD-CT were presented through the clinical application of PCD-CT in the three diseases with the highest mortality rate in China (cardiovascular disease, tumour and respiratory disease). The overall aim of the article is to comprehensively assist medical professionals in understanding the technological innovations and current technical limitations of PCD-CT, while highlighting the urgent problems that PCD-CT needs to address in the coming years.
Sujets)
Tomodensitométrie/méthodes , Photons , Bruit , Chine , Fantômes en imagerieRésumé
@#The radiation risk caused by CT examination is of great concern. Organ dose is considered to be the most significant technical parameter for quantifying the patient radiation dose and assessing the corresponding risk. At present, the methods to obtain patient organ dose caused by CT examination mainly include physical phantom measurement, direct human body measurement, dose conversion coefficient, Monte Carlo simulation, and dose calculation software. Although different methods have their own characteristics and application, the individualization of organ dose is always the goal of radiation protection and dosimetry research. Patient-specific phantom developed with artificial intelligence and GPU-accelerated Monte Carlo simulation make it possible to calculate the patient-specific organ dose, and the patient-specific organ dose extrapolated by the CT detector signal provides a new solution.
Résumé
Based on ASP.NET framework, The Intelligent Estimated System for Rational Deployment of Medical Equipment (MERDIS) is designed and developed with SQL Server 2012 database and C# language. The system is used to realize the rational deployment suggestions and evaluation of medical equipment in hospitals. The system input the data of hospital medical equipment and clinical pathway into the database, and then feedback the deployment information to users which are calculated by big data information, so as to achieve the purpose of giving rational deployment of hospital medical equipment.
Sujets)
Bases de données factuelles , Conception d'appareillage , HôpitauxRésumé
OBJECTIVE@#Putting forward that the risk of using UPS for medical matching is easy to be ignored by managers.@*METHODS@#The method of UPS inspection was designed and used in hospital.@*RESULTS@#The qualified rate of UPS for equipment matching was 66.7% and the problems were corrected. Based on the Internet of Things technology, the UPS monitoring technology was prospected.@*CONCLUSIONS@#It is effective to control the risk of UPS by recognizing the risk of using UPS and specifying the strategy.
Sujets)
Humains , Alimentations électriques , Hôpitaux , TechnologieRésumé
In order to improve the quality of medical equipment after-sales service quality and improve the quality of medical equipment maintenance, this paper discusses the establishment of an evaluation index system to evaluate the quality of ultrasonic diagnostic equipment. From the three aspects of maintenance results, maintenance process and maintenance coverage, the quality of the post-maintenance quality of hospital ultrasound diagnostic equipment manufacturers is objectively evaluated.
Sujets)
Commerce , Matériel de diagnostic , Équipement et fournitures hospitaliers , Maintenance , Gestion des équipements et fournitures hospitaliersRésumé
To explore the effect and experience of quality control circle(QCC) in quality control testing for CT scanners, the quality control circle group was set up to determine the theme of quality control circle, and the causes of the failure of the quality control testing for CT scanners were analyzed, then the corresponding corrective measures were formulated and carried out. After the activity of the quality control circle, the qualified rate of CT quality control testing in the second level 2nd Class of public hospitals and private hospitals in Shanghai increased from 40.6% to 86.1%. By conducting quality control circle activities, we found the problems existed in the quality control testing of CT scanners, and put forward many corresponding corrective measures and solutions which finally improved the qualified rate of CT quality control testing.
Sujets)
Chine , Contrôle de qualité , Tomodensitomètre , Normes de référence , TomodensitométrieRésumé
Objective To study the effect on the environmental radioactivity level and the health of the residents in Shanghai when Qinshan Nuclear Power Station(QNPS) has been in normal operational condition for 17 years. Methods The field monitoring and the sampling analytical method were used for monitoring the radioactivity level in outdoor environment, drinking water, food and soil. Results The outdoor natural radiation level and the radioactivity level in the sample of the environmental media were on the normal background level. There was no distinct change in the environmental radiation level of Jinshan Area when QNPS was in normal operational condition. The radioactivity level in the environmental media was far lower than the limit values specified by the national standard GB. The effective dose of the outdoor natural external exposure for the residents is about 0.102 mSv/a and the effective dose of the internal exposure from the artificial radionuclides 90Sr and 137Cs in food for the residents is about 0.488 μSv/a. Conclusions There is no effect of the radioactive contamination on the environmental radioactivity level and the health of the residents in Shanghai when QNPS has been in normal operational condition for 17 years.