Structural Shielding Design of CT Facility using Monte Carlo Simulation

Radiation application in medicine offers extraordinary benefits. But radiation is like a double-edged sword, it has both benefits and associated risks on the community in contact. To justify the safety of workers and members of the public, regulated use of radiation is assessed by the radiation protection protocols. The aim of this study is to design a Computed Tomography (CT) facility with a simplified model of CT scanner, whose shielding follows the guidelines of National Council on Radiation Protection and Measurements (NCRP) Report No. 147. To design the study model, Monte Carlo (MC) radiation transport code in MCNPX 2.6.0 was used for the simulation. Furthermore, MCNPX was used to measure the photon flux in a vicinity or the detector cell. To validate the functioning of the X-ray tube, the experimental results were compared with the X-ray Transition Energies Database of National Institute of Standards and Technology, U.S. Department of Commerce. The results obtained were within 0.60% of relative error. To confirm the functioning of shielding design, radiation protection quantity, air kerma was measured at several points outside, and inside of the CT room and they were under the radiation dose recommended by NCRP, which demonstrates that the shielding design wassuccessful in blocking the radiation. The study can be used for an easy evaluation of any CT room within the framework of the model of the study

Evaluation of micronuclei in oral mucosa of individuals exposed to ionizing radiation: a pilot study from Celaya, México

Introduction: Occupational exposure to ionizing radiation can potentially lead to adverse health effects, including cancer and genetic defects. Genetic damage caused by radiation can be detected if micronuclei are observed. The objective of this pilot study was to detect the presence of micronuclei in cells of the oral mucosa in inidividuals occupationally exposed to ionizing radiation.Methods:  We implemented a pilot case-control study in which we compared oral mucosa micronuclei in 30 medical and nursing personnel in radiology centers in Celaya, Mexico, with 30 volunteers not exposed to ionizing radiation recruited from a public University. The oral mucosa was brushed and the amount of micronuclei was quantified. Chi-square test or t-test for two proportions were used to compared ionizing radiation and genetic damage between exposed and non-exposed groups.Results: The exposed group had an average of 5.37 ± 3.49 micronuclei and the non-exposed had 0.37 ± 0.61 (P<0.01). In the exposed group, 90% of participants exhibited genetic damage compared to 6.67% in the unexposed group (P<0.05).Conclusion: In this pilot study, medical and nursing staff from radiology centers presented with higher genetic damage compared to control group. Further studies are needed to identify the prevalence of genetic damage due to occupational radiation exposure in Mexico

Evaluation of micronuclei in oral mucosa of individuals exposed to ionizing radiation: a pilot study from Celaya, México

Introduction: Occupational exposure to ionizing radiation can potentially lead to adverse health effects, including cancer and genetic defects. Genetic damage caused by radiation can be detected if micronuclei are observed. The objective of this pilot study was to detect the presence of micronuclei in cells of the oral mucosa in inidividuals occupationally exposed to ionizing radiation. Methods:  We implemented a pilot case-control study in which we compared oral mucosa micronuclei in 30 medical and nursing personnel in radiology centers in Celaya, Mexico, with 30 volunteers not exposed to ionizing radiation recruited from a public University. The oral mucosa was brushed and the amount of micronuclei was quantified. Chi-square test or t-test for two proportions were used to compared ionizing radiation and genetic damage between exposed and non-exposed groups. Results: The exposed group had an average of 5.37 ± 3.49 micronuclei and the non-exposed had 0.37 ± 0.61 (P<0.01). In the exposed group, 90% of participants exhibited genetic damage compared to 6.67% in the unexposed group (P<0.05). Conclusion: In this pilot study, medical and nursing staff from radiology centers presented with higher genetic damage compared to control group. Further studies are needed to identify the prevalence of genetic damage due to occupational radiation exposure in Mexico

Validity and reliability of electroacoustic probe for diagnosis of developmental dysplasia of the hip

Abstract Background Sound transmission is used in the diagnosis of hip dysplasia since the end of the 80’s. Aim of this study is to quantify the validity and reliability of electroacoustic probe for the diagnosis of hip dysplasia in neonates. Methods Diagnostic study included neonates aged 4–28 days, whose parents signed an informed consent. The probe was used three times for comparative sound transmission and with extension/flexion; hip ultrasound was performed with Graf technique as gold standard. Kappa was determined for intraobserver and interobserver reliability; validity was calculated with sensitivity, specificity, and predictive values. Results 100 neonates were included. For the comparative sound transmission, 0.80 and 0.81 Kappa were obtained for the intraobserver and interobserver respectively; with extension/flexion, Kappa 0.98 and 0.95 were obtained for the intraobserver and interobserver respectively. With comparative sound transmission, 44.8%, 97.7%, 76.5% and 91.3% for sensitivity, specificity, positive and negative predictive values, respectively; with extension/flexion test, the sensitivity, specificity, positive and negative predictive values: 82.8%, 99.4%, 96.0%, and 97.1%, respectively. Conclusion The electroacoustic probe is moderate valid and reliable for the diagnosis of developmental dysplasia of the hip. Trial registration Open Science framework https://osf.io/kpf5s/?view_only=0a9682c6w1c842ad8e1d9a66e8dcf03

Gamma-ray shielding features of lithium borate glass doped with Ag, Cd and Zn using Phy-X program

Lithium borate glasses doped with three transition metals: Ag, Cd and Zn were prepared with the melt-quenching method. Dopants concentrations were (Li2B4O7)(100−x) (Zn[NO3]2, CdN2O6, AgNO3) (x = 0%, 1%, 5%). Doped glasses were analyzed and their shielding features were determined. The XRD measurements show the amorphous state of the glasses. Fluorescence analysis shows the characteristic emission of Ag, Cd and Zn and their enhancement is explained. UV–vis spectra were recorded in the interval 200–900 nm, and show the peaks belonging to the plasmon of the three transition metals. The optical energy band gaps were calculated using the Tauc's plot model; also, the refractive index was calculated. Additionally, density (ρ) and molar volume (Vm) were calculated as part of the characterization of the samples. In order to determine the shielding features against gamma-rays the mass attenuation coefficient (μ/ρ)(E), the half value layer (HVL(E)) and the Effective Atomic Number (Zeff(E)) for photons from 0.015 to 15 MeV using the Phy-X program. Resumen: Los vidrios de borato de litio dopados con tres metales de transición: Ag, Cd y Zn se prepararon con el método de enfriamiento por fusión. Las concentraciones de dopantes fueron (Li2B4O7)(100 − x) (Zn[NO3]2, CdN2O6, AgNO3) (x = 0%, 1%, 5%). Se analizaron los vidrios dopados y se determinaron sus características de protección. Las mediciones de XRD muestran el estado amorfo de las gafas. El análisis de fluorescencia muestra la emisión característica de Ag, Cd y Zn y se explica su mejora. Los espectros UV-vis se registraron en el intervalo 200-900 nm y muestran los picos pertenecientes al plasmón de los tres metales de transición. Los huecos de las bandas de energía óptica se calcularon utilizando el modelo de gráfico de Tauc; además, se calculó el índice de refracción. Además, la densidad (ρ) y el volumen molar (Vm) se calcularon como parte de la caracterización de las muestras. Para determinar las características de blindaje contra los rayos gamma, el coeficiente de atenuación de masa (μ/ρ)(E), la capa de valor medio (HVL(E)) y el Número Atómico Efectivo (Zeff(E)) para fotones de 0.015 a 15 MeV usando el programa Phy-X