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This report unveils the outcomes of measurements of 222Rn exhalation rates, effective 226Ra content, and the annual effective dose for rocks and soil collected in the vicinity and far from the seismically active Kopili Fault Zone, India. LR-115 (II) nuclear track detector has been used to investigate radiation exposure in the seismically active fault zone and gneissic complex of the Shillong Plateau, which have significant geological characteristics and frequently produce earthquakes. In this study, 222Rn mass exhalation rates for granite, gneiss, and soil samples collected near and far from the fault were calculated to be in the ranges of 73.2–83.0, 11.0–14.8, 21.1–70.7 and 34.3–65.5, 6.4–9.9, 19.1–28.9 mBq kg−1 h−1, respectively. Surface exhalation rates of 222Rn for granite, gneiss, and soil samples collected near and far from the fault varied between 2428.8–2751.7, 365.6–491.9, 698.3–2345.9, and 1138.6–2172.7, 211.9–328.2, 634.9–960.0 mBq m−2 h−1, respectively. The 226Ra contents of granite, gneiss, and soil collected in similar distributions were found to vary from 9.76–11.06, 1.47–1.98, 2.8–9.4, and 4.58–8.74, 0.85–1.32, 2.6–3.6 Bq kg−1, respectively. The annual effective doses attributed to 222Rn inhalation from exposure to the samples were calculated to be in the ranges of 176.3–199.8, 26.5–35.7, 50.7–170.3 and 82.7–157.7, 15.4–23.8, 46.1–69.7 μSv y−1, respectively, for granite, gneiss, and soil. The lifetime fatality-risks have also been analysed in this study. The samples that were collected in close proximity to the fault showed higher values than those that were collected farther away. However, the results reveal that the measured values are within the globally recognised permissible range. [ABSTRACT FROM AUTHOR]

Interventional cardiologists face significant radiation exposure during interventional cardiology procedures. Therefore, this study focuses on assessing radiation exposure among interventional cardiologists during their procedures. Specifically, it aims to determine the effectiveness of both single and double dosimeter methods in estimating annual occupational radiation doses. This research holds pioneering significance as it represents the very first study undertaken in Sri Lanka. Thirteen interventional cardiologists performed 486 interventional cardiology procedures over three months in three different healthcare institutes. Active Hp(10) dosimeters were placed to measure radiation exposure. Effective doses were calculated using single and double dosimetric algorithms. Annual occupational doses were assessed on an operator basis. Statistical analyses were conducted to assess algorithmic differences and dose variations using the Kruskal–Wallis test and linear regression. The highest annual occupational dose for each dosimetric algorithm received as 2.00 ± 0.24 mSv, 2.29 ± 0.48 mSv, 3.35 ± 0.71 mSv, and 2.64 ± 0.42 mSv, respectively, and remained below the recommended safety limit of 20 mSv/year. The Kruskal–Wallis test revealed no significant differences in the effective doses among double dosimetric algorithms, as well as between single and double dosimetric algorithms (p > 0.05). Linear regression showed strong correlations among various algorithms, demonstrating consistency. The findings of this study hold significant effects on interventional cardiology practice in Sri Lanka, enhancing radiation safety and monitoring. [ABSTRACT FROM AUTHOR]

Computed tomography (CT) is the gold standard for diagnosing sinusitis and anatomical variations and a guide for paranasal sinus (PNS) surgeries. High doses of radiation lead to increased risk of head and neck malignancies, radiation-induced cataracts, hypothyroidism, and hyperthyroidism. The purpose of this study was to assess the effectiveness of low-dose CT as compared to standard-dose CT in the identification of anatomical variants of paranasal sinus and rhinosinusitis. This was a prospective cross-sectional study consisting of 72 patients who were divided equally into cases (underwent low-dose CT for PNS) and controls (underwent CT for PNS using standard dose protocols). Prevalence of anatomical variants and sinusitis were compared. Image quality was assessed using volume CT dose index (CTDIvol), dose length product (DLP), scan length, and noise. Subjective assessment was done by two radiologists, and scores were given. The comparison and analysis of the quantitative and qualitative variables were done. Anatomical variants were comparable among cases and controls, with post-sellar sphenoid being most common and paradoxical middle turbinate being least common surgically important variant. The difference in mean SD of CTDIvol (mGy), DLP (mGy-cm), effective dose (mSv), globe, and air noise between low and standard doses was statistically significant. A moderate agreement (with kappa 0.50) in cases and substantial agreement (with kappa 0.69) in controls was observed between both observers. Low-dose CT PNS and standard-dose CT PNS are comparable in delineating the paranasal sinus anatomy, with a 3.53× reduction of effective radiation dose to patients. [ABSTRACT FROM AUTHOR]

Elevated levels of radionuclides and toxic metals in water can potentially influence the growth of fish during their mature stages, posing a risk of human exposure through the consumption of contaminated fish. This investigation assessed the levels of health risk of naturally occurring radionuclides and heavy metals in commonly consumed African catfish, White catfish and Nile tilapia fish species in the Epe Waterside region of Lagos, Nigeria, using a sodium iodide detector and an atomic absorption spectrometer. The activity concentrations (Bq/kg) of 40K (29.1±21.0-823.5±18.2) were higher than 226Ra (27.1±87.8-202.7±50.3) and 232Th (52.9±7.4-600.2±7.0), with mean values exceeding the permissible limits set by WHO. The mean committed effective dose rate is above the 50 mSv recommended by ICRP. The mean annual intake and cancer risks for people who consume fish on a weekly basis (nutrition statistics for seven, five, three, and one day per week) were relatively high, surpassing the permissible limit of 1.0x10-6 as recommended by WHO. The concentrations of heavy metals (Zn: 0.026-1.344, Cu: 0.008-0.055, and Cd: 0.048-0.250 mg/kg) exhibited mean values that fell within the acceptable limits defined by FAO/WHO, with the exception of Pb, which recorded a higher concentration ranging from 2.51 to 3.39 mg/kg. The fish's natural habitats (lagoon) have been contaminated by toxins, likely originating from industries, waste disposal activities, agrochemicals, rusty pipes, and other fittings. Encouraging the cultivation of fishes in domesticated ponds around the study area can reduce the risk of consuming contaminated fish and other seafood. [ABSTRACT FROM AUTHOR]

To detect tritium levels in the human body, tritium in the urine must be measured. The investigation of the level of tritium activity in the urine of workers of the Iraqi Nuclear Research Center (INRC) has been realized in order to assess vocational exposure levels. Three worker groups in INRCs were chosen, involved in the Central Laboratories Directorate (CLD), the Decommissioning Directorate (DD), and the Radioactive Waste Treatment and Radioactive Waste Store Directorate (WTWSD), among others in Al- Tuwiatha site, in addition to the control group, as the research targets. Tritium concentration was determined in urine samples from 52 workers (aged 32-61) and 13 control people (aged 30-58). 65 urine samples of 50 mL were collected and analyzed. The Eichrom's Tritium Column way was used to handle the samples of urine, and the distillate tritium activity concentration was then assessed using Liquid Scintillation Counter. The effective and annual effective doses were estimated for the internal doses. The accuracy of urine sample measurements had been tested. The highest level of tritium activity samples of urine from three groups of workers in INRCs is 65.401 Bq/L, and for control group is 39.300 Bq/L, activity of tritium concentrations estimated by using counting scintillation of liquid (LSC) were found to be lower than Minimum Detectable Activity (MDA) of 1.95 Bq/L. The effective and annual effective dose from tritium was also assessed depend on results measured previously and standard values adapted by the International Commission on Radiological Protection. The effective highest doses for workers groups and control group were 497.048 ×10-3 and 298.680×10-3 nSv respectively. Highest annual effective dose 5757.773×10-³ and 5167.042×10-3 nSv respectively. These results were lowest than the allowed effective dose for the workers. [ABSTRACT FROM AUTHOR]

The Sentinel Lymph Node (SLN) or Sentinel Lymph Node Biopsy (SLNB) technique involves various professionals from different departments in clinical settings to manage breast cancer patients properly. Tracing the nodular involvement of breast cancer patients requires radiation source Tc99m labeled with colloidal albumin to be injected at the tumor site. The patient becomes a radiation source for a sufficient time, which concerns the Nuclear Medicine (NM) and surgical staff. The study aims to provide the radiation doses of staff in the NM department during the SLN scintigraphy procedure and obtain an empirical model for calculating the radiation doses to staff in the surgical department from that particular patient. Radiation doses in SLN technique for breast cancer patients are minimal, and a sufficient number of SLN biopsy procedures can be performed by hospital staff within the category of non-radiation workers.

BackgroundDental imaging plays a crucial role in diagnosis and treatment planning, with cone-beam computed tomography (CBCT) and medical computed tomography (CT) being two common modalities. This study aims to compare the radiation doses associated with CBCT and medical CT imaging in dental applications to assess their relative safety and efficacy. Materials and MethodsWe conducted a retrospective study using data from 100 patients who underwent both CBCT and medical CT scans for dental purposes. The radiation doses were measured in terms of dose-length product (DLP) for medical CT and dose-area product (DAP) for CBCT. The effective dose (ED) was calculated using appropriate conversion factors. Patient demographics, scan parameters, and radiation doses were recorded and analyzed. ResultsThe results indicated that the mean DLP for medical CT scans was 220 mGycm, whereas the mean DAP for CBCT scans was 150 mGycm². The corresponding mean effective doses for medical CT and CBCT were 2.5 mSv and 1.8 mSv, respectively. The radiation dose from CBCT was found to be approximately 28% lower than that from medical CT. ConclusionThis study demonstrates that CBCT imaging for dental applications results in significantly lower radiation doses compared to medical CT. While both modalities provide valuable diagnostic information, the choice of imaging technique should consider the balance between diagnostic quality and radiation exposure, especially for pediatric and high-risk patients. Dental practitioners should be aware of the potential dose reduction benefits associated with CBCT when appropriate for the clinical scenario.

Abstract Background Ciprofol is a novel intravenous sedative and anesthetic. Studies have shown that it features a rapid onset of action, a fast recovery time, slight inhibition of respiratory and cardiovascular functions, and a low incidence of adverse reactions. This study aims to explore the median effective dose (ED50) and the 95% effective dose (ED95) of ciprofol in inhibiting responses to gastroscope insertion when combined with a low dose of alfentanil, and to evaluate its safety, to provide a reference for the rational use of ciprofol in clinical practices. Methods We included 25 patients aged 18–64 years of either sex who underwent gastroscopy under intravenous general anesthesia, with a Body Mass Index (BMI) 18–28 kg/m2, and an American Society of Anesthesiologists (ASA) grade I or II. In this study, the dose-finding strategy of ciprofol followed a modified Dixon’s up-and-down method with an initial dose of 0.30 mg/kg and an increment of 0.02 mg/kg. Ciprofol was administered after intravenous injection of 7 µg/kg of alfentanil, and 2 min later a gastroscope was inserted. When the insertion response of one participant was positive (including body movement, coughing, and eye opening), an escalation of 0.02 mg/kg would be given to the next participant; otherwise, a de-escalation of 0.02 mg/kg would be administered. The study was terminated when negative response and positive response alternated 8 times. A Probit model was used to calculate the ED50 and ED95 of ciprofol in inhibiting responses to gastroscope insertion when combined with alfentanil. Patients’ recovery time, discharge time, vital signs and occurrence of adverse reactions were recorded. Results The ED50 of single-dose intravenous ciprofol injection with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Patients’ recovery time and discharge time were 11.04 ± 1.49 min and 9.64 ± 2.38 min, respectively. The overall incidence of adverse reactions was 12%. Conclusion The ED50 of ciprofol combined with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Ciprofol showed a low incidence of anesthesia-related adverse events. Trial registration http://www.chictr.org.cn (ChiCTR2200061727).

Abstract Aim Positron emission tomography (PET) using 124I-mIBG has been established for imaging and pretherapeutic dosimetry. Here, we report the first systematic analysis of the biodistribution and radiation dosimetry of 124I-mIBG in patients with neural crest tumours and project the results to paediatric patient models. Methods Adult patients with neural crest tumours who underwent sequential 124I-mIBG PET were included in this retrospective single-center analysis. PET data were acquired 4, 24, 48, and/or 120 h after administration of a mean of 43 MBq 124I-mIBG. Whole-body counting and blood sampling were performed at 2, 4, 24, 48 and 120 h after administration. Absorbed organ dose and effective dose coefficients were estimated in OLINDA/EXM 2.2 according to the MIRD formalism. Extrapolation to paediatric models was performed based on mass-fraction scaling of the organ-specific residence times. Biodistribution data for adults were also projected to 123I-mIBG and 131I-mIBG. Results Twenty-one patients (11 females, 10 males) were evaluated. For adults, the organs exposed to the highest dose per unit administered activity were urinary bladder (1.54 ± 0.40 mGy/MBq), salivary glands (0.77 ± 0.28 mGy/MBq) and liver (0.65 ± 0.22 mGy/MBq). Mean effective dose coefficient for adults was 0.25 ± 0.04 mSv/MBq (male: 0.24 ± 0.03 mSv/MBq, female: 0.26 ± 0.06 mSv/MBq), and increased gradually to 0.29, 0.44, 0.69, 1.21, and 2.94 mSv/MBq for the 15-, 10-, 5-, 1-years-old, and newborn paediatric reference patients. Projected mean effective dose coefficients for 123I-mIBG and 131I-mIBG for adults were 0.014 ± 0.002 mSv/MBq and 0.18 ± 0.04 mSv/MBq, respectively. Conclusion PET-based derived radiation dosimetry data for 124I-mIBG from this study agreed well with historical projected data from ICRP 53. The effective dose coefficients presented here may aid in guidance for establishing weight-based activity administration protocols.

Electron paramagnetic resonance (EPR) dosimetry for a tooth from an individual exposed is well known as retrospective dosimetry in radiological accidents. A major constraint of the conventional X-band tooth-EPR dosimetry is the necessity to extract the tooth of the exposed patient for dose assessment. In this study, to conduct the dose assessments of exposed patients through part-extraction of tooth enamel, the minimum detectable dose (MDD) of the tooth enamel was evaluated based on the amount of mass. Further, a field test was conducted via intercomparison using various dose assessment methods to verify the feasibility of X-band tooth-EPR dosimetry using the minimum mass of tooth enamel. The intercomparison results demonstrated that effective dose determination via X-band tooth-EPR dosimetry is reliable. Consequently, it was determined that the minimum mass of tooth enamel required to evaluate an absorbed dose above 0.5 Gy is 15 mg. Thus, EPR dosimetry using 15 mg of tooth enamel can be applied in the triage and initial medical response stages for patients exposed during radiological accidents. This approach represents an advancement in managing radiological accidents by offering a more efficient and less invasive method of dose assessment.

Employees of nuclear medicine facilities performing medical procedures with the use of open radioactive sources require continuous detailed control of exposure to ionizing radiation.Thermoluminescent (TL) detectors placed in dosimeters: for the whole body, for lenses, ring and wrist dosimeters were used to assess exposure.The highest whole-body exposure of (1.70 ± 1.09) μSv/GBq was recorded in nurses administering radiopharmaceutical to patients. The highest exposure to lenses and fingers was recorded for employees of the quality control zone and it was (8.08 ± 2.84) μSv/GBq and a maximum of (1261.46 ± 338.93) μSv/GBq, respectively. Workers in the production zone received the highest doses on their hands, i.e. (175.67 ± 13.25) μSv/GBq.The measurements performed showed that the analyzed workers may be classified as exposure category A. Wrist dosimeters are not recommended for use in isotope laboratories due to underestimation of ionizing radiation doses. Appropriately selected shields, which significantly reduce the dose received by employees, must be used in isotope laboratories. Periodic measurements confirmed that the appropriate optimization of exposure reduces the radiation doses received by employees.

Interventional examinations are associated with high levels of patient exposure per examination, which makes it particularly important to monitor individual patient doses and to assess radiation risks. The aim of this study was the assessment of effective doses for fluoroscopy-guided balloon dilatation of benign esophageal strictures, whichwasperformedonpediatricpatientsaged 1 to 2 yearsatthe Departmentof Radiosurgical Methodsof Diagnosis and Treatment of St. Petersburg State Pediatric Medical University. Patient exposure patterns were basedonourowndatacollection. Thecalculationofeffectiveandorgandosesofpatientsnormalizedbythevalue of the dose area product measured during the study was carried out using PCXMC 2.0 software. The conversion coefficients from the dose area product to the effective dose were calculated using tissue weighting coefficients from the ICRP Publications 60 and 103 their values were 10.7 and 11.7 µSv/cGy cm2, respectively. The results of verification of the method indicated that the use of inappropriate conversion coefficients leads to an almost double underestimation of children’s effective doses. Differences in the values of conversion coefficients are significant and are explained by differences in voltage, source to image distance, and irradiation field size. A simplified model of patient exposure was proposed, which is described by a single irradiation field. The assessment of effective doses using multi-field and single-field irradiation model shows comparable results, which allows using the differentiated approach to the assessment of radiation doses of patients.

The dose from a possible accident at a microwave-based spent resin mixture treatment facility that was to be installed and operated at the Wolsong nuclear power plant was analyzed to evaluate the radiological safety prior to its installation and operation. The dose to which workers and nearby residents are likely to be exposed was calculated based on the atmospheric dispersion and deposition factors using the XOQDOQ code. The highest atmospheric dispersion factors were 1.349E-05 s/m3 (workers) and 1.534E-06 s/m3 (residents). The highest doses due to emissions from the mock-up tank before operation were 1.91E-06 mSv (workers) and 1.78E-07 mSv (residents). Even after 3 h of operation, emissions from the mock-up tank had the greatest impact ranging from 4.63E-08 to 1.24E-06 mSv (workers) and 2.74E-10 to 1.16E-07 mSv (residents), respectively. The doses were 7.09E-09–4.55E-07 mSv and 4.18E-11–4.25E-08 mSv at 4–5 h of operation, and the maximum doses after operation reached 5.69E-07 mSv and 5.31E-08 mSv for the workers and residents, respectively.Even at the exclusion area boundary (EAB), 4.76E-08–9.51E-07 mSv (annual dose:9.52E-05–1.90E-03 mSv/y) was below the dose limit of the EAB, and the safety of the facility installation inside the NPP was confirmed.

The effective dose (ED) in computed tomography (CT) may be calculated by multiplying the dose–length product (DLP) by a conversion factor. As children grow, automatic exposure control increases the DLP, while the conversion factor decreases; these two changes affect the ED in opposite ways. The aim of this study was to investigate the methods of ED estimation according to age in pediatric brain CT. We retrospectively analyzed 980 brain CT scans performed for various clinical indications in children. The conversion factor at each age, in integer years, was determined based on the values at 0, 1, 5, and 10 years provided by the International Commission on Radiological Protection (ICRP), using a curve (curve method) or lines (linear method). In the simple method, the ED was estimated using the ICRP conversion factor for the closest age. We also analyzed the ED estimated by a radiation dose management system. Although the median DLP at each age increased with age, the median ED estimated by the curve method was highest at 0 years, decreased with age, and then plateaued at 9 years. The linear method yielded mildly different results, especially at 2 and 3 years. The ED estimated by the simple method or the radiation dose management system showed inconsistent, up-and-down changes with age. In conclusion, the ED in pediatric brain CT decreases with age despite increased DLP. Determination of the conversion factor at each age using a curve is expected to contribute to estimating the ED in pediatric CT according to age.

The equilibrium factor F is one of the parameters that should be considered when assessing the effective dose based on radon activity concentration. Since the equilibrium factor in various environments ranges theoretically from a value close to 0 to 1, it is expected that dose assessment based on one recommended coefficient value may lead to an underestimation or overestimation of the dose. That is why it is essential to measure this quantity if the basis for dose assessment is the radon concentration and not the concentration of radon decay products. The equilibrium factors were determined based on measurements of radon activity concentration and potential alpha energy concentration and varied from 0.15 to 0.94, with an arithmetic mean of 0.55. The average effective dose calculated for the employee taking into account these values was 31 mSv, assuming an annual working time of 1800 h. In turn, the average effective dose calculated for the equilibrium factor of 0.2 as recommended by the International Commission on Radiological Protection (ICRP) was equal to 13 mSv.

adiation risks assessment in medical exposure of patients is one of the mandatory steps in justifying the medical radiological examinations. The main objectives of such assessment are the need for benefit-harm analysis, when prescribing a study, and informing patients or their legal representatives about the radiation risk associated with the recommended examination. The traditional approach to radiation risk assessment is the use of measures based on lifetime morbidity and/or mortality due to radiation exposure in risk characterization. However, the development of the methodology of population health assessment and the need to harmonize the methodology of radiation risk assessment with risks from exposure to factors of other nature imply the use of more informative generalized health indicators in the assessment of exposure to harmful environmental factors. The aim of actual work was to apply the developed methodology of radiation detriment assessment to characterize the risk by calculating DALY (number of years of healthy full life lost due to exposure to ionizing radiation) values for different sex and age groups of Russian patients undergoing computed tomography. To achieve this goal, the previously developed method of estimating the number of years of healthy life lost due to exposure to ionizing radiation was used. Calculations were performed with the use of a specially developed computer program based on the models of the International Commission on Radiological Protection using medical and demographic data of Russian population. The article presents the results of DALY calculation for six types of computed tomographic examinations. The use of DALY to characterize risk instead of the most widely used value of radiation detriment (or lifetime risk of death, relating the harm from the reduction in the quality of life in the case of non-fatal oncological disease) is an attempt to harmonize the methodology of radiation risk assessment with the methodologies of other kind of health risks. One of the directions of calculation results usage is the development of sexand age-dependent risk coefficients associated with medical exposure of patients. The analysis of the obtained results showed that the age distribution of risks agrees well with the data presented in the methodological recommendations MR 2.6.1.0215-20 “Assessment of radiation risk to patients in radiology examinations”. It is also shown that the DALY indicator can serve as a basis for comparative assessment of obtainable and avoidable risks in the field of medical radiation exposure of patients.

The article presents the analysis of the structure of computed tomography diagnostics according to the forms of the federal state statistical observation (radiation-hygienic passports in 2011–2021, forms № 3-DOZ in 2011-2021 and forms № 30 in 2014–2020) in order to assess the status of CT diagnostics in the Russian Federation and identify the main trends in the development of this type of radiation diagnostics and patient doses. In 2011–2021, there was a sharp development of CT diagnostics in the Russian Federation – an increase in the number of CT examinations per 1000 people (up to a factor of 5.9 – from 32 CT examinations per 1000 people to 189 CT examinations per 1000 people) and the contribution of CT in the collective dose from medical diagnostic exposure (3 times from 26% to 77%). The number of CT examinations per 1 CT device from 2014 to 2019 increased by 2 thousand (52%), and in 2020 by another 1.85 thousand (32% compared to 2019) and reached 7.7 thousand. The increase in the number of CT examinations was mainly due to the increased use of CT equipment. The main contribution to the structure and collective dose of computed tomography in 2021 is made by examinations of chest (58%/65%), abdomen (8%/14%), pelvis and hips (3%/4%), skull and maxillofacial area (18%/7%). In 2011-2021 for chest CT examinations, the average effective dose was in the range from 4.2 to 5.9 mSv per examination, for abdomen – from 6.5 to 9.2 mSv, for pelvis and hips – 5 to 6.7 mSv, for skull and maxillofacial area – 1.5 to 2.4 mSv. The COVID-19 pandemic in 2020-2021 caused a change in the structure of CT examinations and collective dose in the Russian Federation – the chest CT examinations occupied the first place of the contribution to the number of examinations and the collective dose. The number of CT examinations per 1000 people and the contribution of CT to the collective dose from medical diagnostic exposure in the Russian Federation were significantly lower than those in foreign countries (up to a factor of 3.5 in the number of CT examinations per 1000 people and up to a factor of 1.6 of the contribution of CT to the collective dose).

Since the emergence of the coronavirus and the international community's attention to this virus, researchers and medical staff in hospitals have put approaches and methods for dealing with it and early diagnosis on their agenda. In this study, one of the method that called the Impact Dose program has been presented to calculate the absorbed and effective dose of people infected with the Covid-19 virus using CT scans of the respiratory tract. This is an analytical cross-sectional study that was conducted at Isfahan Shariati Hospital. The study is included of the 42 patients with Covid-19, who were selected based on doctor's opinion. The effective and absorbed dose were estimated by using the Impact Dose program, which is based on Monte Carlo. The data were analyzed using SPSS-24 software. The effective dose and DLP were reported as 1.67 mSv and 80.08 mGy.cm, respectively. The absorbed dose and effective dose were found to be higher in women than in men. The multiple CT scans of patients for the diagnosis of Covid-19 resulted in a very high absorbed dose, and lung sonography was recommended as an alternative method due to its high accuracy, similar to CT scans, in diagnosing pneumonia.

The form of federal governmental statistical surveillance № 3-DOZ, titled “Data on patient doses from medical X-ray examinations,” has changed significantly by the order of Rosstat N 880. In particular, the structure of the form’s has been revised: studies involving high doses were dedicated from the rest; the section on radionuclide diagnostics has been redesigned; the information on the levels of patient exposure when using individual radionuclides and in hybrid studies have been displayed; information on the number of radiological studies and collective doses for pediatric patients have been introduced; and the number of studies for which typical (average) effective doses of patients are presented has been reduced. The structure of the updated form № 3-DOZ is presented within the framework of this work. In this article, recommendations for filling out № 3-DOZ have been developed in order to increase the reliability of the data provided and reduce the number of procedural errors. This work is a continuation of the article Vodovatov A.V., Chipiga L.A., Bratilova A.A., Druzhinina P.S., Shatskiy I.G., Petryakova A.V., Sarycheva S.S., Biblin A.M., Akhmatdinov R.R., Kapyrina Yu.N., Soldatov I.V., Puzyrev V.G., and Ryzhov S.A. “Update of the federal governmental statistical surveillance form № 3-DOZ “Data on patient doses from medical X-ray examinations”. Perquisites for the update, published in the journal Radiatsionnaya Gygiena (2023. Vol. 16, N 2. P. 126–136. DOI: https://doi.org/10.21514/1998-426X-2023-16-2-126-136).

The effective dose is an important tool in the radiation protection community because it represents the health risk associated with different procedures involving ionizing radiation, and therefore it allows comparing them. Therefore, accurate determination of the effective dose for nuclear medicine procedures is important. In this study, the effective dose per unit activity administered was calculated for some of the 99mTc-based radiopharmaceuticals. The MIRD method was used for the calculation of organ’s absorbed doses using the ICRP 110 adult male and female reference phantoms. The biokinetic data was taken from the ICRP Publications 128 and 53. Then, the effective doses were calculated using the ICRP 103 tissue weighting factors. The results show that with some exceptions, the calculated effective doses using new phantoms and tissue weighting factors are lower than the ICRP published data. This reduction is significant in some cases and can significantly reduce the collective effective dose of patients.

Background: The same conversion factors (k-factors) of Single CT (SECT) are applied to estimate the Effective Dose (ED) in Dual Energy Computed Tomography (DECT). However, k-factors for different organs need independently validating for DECT, due to the different conditions in DECT.Objective: This study aimed to calculate organ dose and k-factors in different imaging protocols (liver, chest, cardiac, and abdomen) for male and female phantoms.Material and Methods: This Monte Carlo Simulation study used Monte Carlo N-Particle (MCNP) code for modeling a Siemens Somatom Definition Flash dual-source CT scanner. The organ dose, dose length product, and k-factors were calculated for the Medical Internal Radiation Dose (MIRD) of male and female phantoms.Results: For the male phantom, the k-factors for the liver, chest, cardiac, and abdomen-pelvis imaging protocols are equal to 0.020, 0.012, 0.016, and 0.014 mSv.mGy−1cm−1, respectively. For the female phantom, the corresponding values are equal to 0.026, 0.023, 0.036, and 0.018, respectively. These values for DECT are different from those corresponding values for SECT, especially for the female phantom. Conclusion: The calculated k-factors for DECT can be used as reference values for the estimation of ED in DECT.

Radon gas in the natural environment mainly comes from the release of local bedrock geology and easily accumulate in closed spaces such as basements and caves. This study was performed to investigate the radon concentrations in Mimpi Cave, Bantimurung-Bulusaraung National Park, in the Maros karst area, South Sulawesi, and discussed a possible relationship between the radon concentrations and the local geology. Measurements were carried out using a passive detection technique with CR-39 nuclear tracks detectors by exposing it for a period of three months. The 222Rn levels measured inside the cave ranges from 64.03 Bq m‑3 to 3396.02 Bq m‑3, with an average value of 1075.05 Bq m‑3.The results are comparable with radon concentration in different caves environments reported from other surveys in several countries. Geological background of the Maros Karst areas could sustain the measured radon values, due to the presence of limestone rock with a mineral composition which can lead to higher radon concentrations in Mimpi Cave.

IntroductionRemimazolam (RMZ) is a novel intravenous sedative drug of ultra-short benzodiazepine. The optimal dose of RMZ plus butorphanol for sedation during first trimester artificial abortion is unknown. Therefore, the present study aimed to evaluate the median effective dose (ED50) of RMZ combined with different doses of butorphanol on the sedative effect for first-trimester artificial abortion.MethodsSixty-one female patients were randomly assigned to Group B10 (31 patients) and Group B15 (30 patients). RMZ was administered 5 min after IV butorphanol at doses of 10 μg/kg (Group B10) and 15 μg/kg (Group B15). Cervical dilatation at the time of using a cervical dilating rod, if the patient has body movement and affects the gynecologist’s operation, we define it as “Ineffective.” Therefore, the dose of RMZ was increased in the next patient. Otherwise, it was defined as “Effective,” and the dose of RMZ was reduced in the next patient. According to the pre-experiment, the first dose of RMZ in the first patient was 0.35 mg/kg, and the adjacent geometric dose ratio was 0.9. The centered isotonic regression was performed to determine the ED50 of RMZ. The total RMZ dose administered, recovery time, and anesthesia-related adverse events were all recorded.ResultsThe ED50 (90% CI) of RMZ was 0.263 (0.215–0.310) mg/kg in Group B10, and 0.224 (0.191–0.261) mg/kg in Group B15, respectively. The recovery time in Group B10 was significantly shorter than in Group B15 (9.8 ± 2.3 vs. 12.5 ± 3.6 min, p ≤ 0.001). There was no significant difference in the incidence rate of all anesthesia-related adverse events between the two groups (p > 0.05).ConclusionThe ED50 of RMZ combined with a 10 μg/kg or 15 μg/kg dose of butorphanol was 0.263 and 0.224 mg/kg during painless first trimester artificial abortion. However, RMZ combined with a 10 μg/kg dose of butorphanol seems to have a shorter recovery time.Clinical trial registrationhttps://www.chictr.org.cn/bin/project/edit?pid=166623.

Synthetic exendin-4 (EX4, exenatide), is a GLP-1 receptor agonist used clinically to treat glycemia in Type-2 diabetes mellitus. EX4 also promotes weight loss and alters food reward-seeking behaviors in part due to activation of GLP-1 receptors in the mesolimbic dopamine system. Evidence suggests that GLP-1 receptor activity can directly attenuate cue-induced reward seeking. Here, we tested the effects of EX4 (0.6, 1.2, and 2.4 μg/kg, i.p.) on incentive cue (IC) responding, using a task where rats emit a nosepoke response during an intermittent reward-predictive IC to obtain a sucrose reward. EX4 dose-dependently attenuated responding to ICs and increased the latencies to respond to the IC and enter the sucrose reward cup. Moreover, EX4 dose-dependently decreased the total number of active port nosepokes for every cue presented. There was no effect of EX4 on the number of reward cup entries per reward earned, a related reward-seeking metric with similar locomotor demand. There was a dose-dependent interaction between the EX4 dose and session time on the responding to ICs and nosepoke response latency. The interaction indicated that effects of EX4 at the beginning and end of the session differed by the dose of EX4, suggesting dose-dependent pharmacokinetic effects. EX4 had no effect on free sucrose consumption behavior (i.e., total volume consumed, bout size, number of bouts) within the range of total sucrose volumes obtainable during the IC task (~3.5 ml). However, when rats were given unrestricted access for 1 h, where rats obtained much larger total volumes of sucrose (~30 ml), we observed some dose-dependent EX4 effects on drinking behavior, including decreases in total volume consumed. Together, these findings suggest that activation of the GLP-1 receptor modulates the incentive properties of cues attributed with motivational significance.

Elevated levels of radionuclides and toxic metals in water can potentially influence the growth of fish during their mature stages, posing a risk of human exposure through the consumption of contaminated fish. This investigation assessed the levels of health risk of naturally occurring radionuclides and heavy metals in commonly consumed African catfish, White catfish and Nile tilapia fish species in the Epe Waterside region of Lagos, Nigeria, using a sodium iodide detector and an atomic absorption spectrometer. The activity concentrations (Bq/kg) of 40K (29.1±21.0-823.5±18.2) were higher than 226Ra (27.1±87.8-202.7±50.3) and 232Th (52.9±7.4-600.2±7.0), with mean values exceeding the permissible limits set by WHO. The mean committed effective dose rate is above the 50 mSv recommended by ICRP. The mean annual intake and cancer risks for people who consume fish on a weekly basis (nutrition statistics for seven, five, three, and one day per week) were relatively high, surpassing the permissible limit of 1.0×10-6 as recommended by WHO. The concentrations of heavy metals (Zn: 0.026-1.344, Cu: 0.008-0.055, and Cd: 0.048-0.250 mg/kg) exhibited mean values that fell within the acceptable limits defined by FAO/WHO, with the exception of Pb, which recorded a higher concentration ranging from 2.51 to 3.39 mg/kg. The fish's natural habitats (lagoon) have been contaminated by toxins, likely originating from industries, waste disposal activities, agrochemicals, rusty pipes, and other fittings. Encouraging the cultivation of fishes in domesticated ponds around the study area can reduce the risk of consuming contaminated fish and other seafood.

Background: We are always concerned about radiation exposure during dental imaging procedures. We explore the crucial differences in radiation doses between Cone Beam Computed Tomography (CBCT) and Medical computed tomography (CT) imaging, aiming to shed light on the safety and efficiency of these techniques. Materials and Methods: In this study, we conducted a comprehensive analysis using state-of-the-art dental imaging equipment. We employed phantoms that simulated real dental scenarios, ensuring accuracy in our measurements. The radiation doses were measured with precision dosimeters, and various exposure settings were tested to obtain a comprehensive dataset. Results: Our findings reveal substantial differences in radiation doses between CBCT and Medical CT for dental applications. In the case of CBCT, the average effective dose was found to be approximately 100 microsieverts (μSv), making it a preferable choice for routine dental imaging. Medical CT, on the other hand, yielded significantly higher radiation exposure, with an average effective dose exceeding 500 μSv, emphasizing its need for specific clinical scenarios. Conclusion: In conclusion, the choice between CBCT and Medical CT for dental applications should be made with careful consideration of radiation dose implications. CBCT emerges as the safer and more efficient option for routine dental imaging, offering a lower radiation burden to patients while still delivering high-quality diagnostic images. However, Medical CT may be necessary for specialized cases where the additional radiation risk is justified by diagnostic requirements.

Aim: Positron emission tomography (PET) using 124I-mIBG has been established for imaging and pretherapeutic dosimetry. Here, we report the first systematic analysis of the biodistribution and radiation dosimetry of 124I-mIBG in patients with neural crest tumours and project the results to paediatric patient models. Methods: Adult patients with neural crest tumours who underwent sequential 124I-mIBG PET were included in this retrospective single-center analysis. PET data were acquired 4, 24, 48, and/or 120 h after administration of a mean of 43 MBq 124I-mIBG. Whole-body counting and blood sampling were performed at 2, 4, 24, 48 and 120 h after administration. Absorbed organ dose and effective dose coefficients were estimated in OLINDA/EXM 2.2 according to the MIRD formalism. Extrapolation to paediatric models was performed based on mass-fraction scaling of the organ-specific residence times. Biodistribution data for adults were also projected to 123I-mIBG and 131I-mIBG. Results: Twenty-one patients (11 females, 10 males) were evaluated. For adults, the organs exposed to the highest dose per unit administered activity were urinary bladder (1.54 ± 0.40 mGy/MBq), salivary glands (0.77 ± 0.28 mGy/MBq) and liver (0.65 ± 0.22 mGy/MBq). Mean effective dose coefficient for adults was 0.25 ± 0.04 mSv/MBq (male: 0.24 ± 0.03 mSv/MBq, female: 0.26 ± 0.06 mSv/MBq), and increased gradually to 0.29, 0.44, 0.69, 1.21, and 2.94 mSv/MBq for the 15-, 10-, 5-, 1-years-old, and newborn paediatric reference patients. Projected mean effective dose coefficients for 123I-mIBG and 131I-mIBG for adults were 0.014 ± 0.002 mSv/MBq and 0.18 ± 0.04 mSv/MBq, respectively. Conclusion: PET-based derived radiation dosimetry data for 124I-mIBG from this study agreed well with historical projected data from ICRP 53. The effective dose coefficients presented here may aid in guidance for establishing weight-based activity administration protocols. [ABSTRACT FROM AUTHOR]

Background: Studies of tin spectral filtration have demonstrated potential in reducing radiation dose while maintaining image quality for unenhanced computed tomography (CT) scans. The extent of dose reduction, however, was commonly measured using the change in the scanner's reported CTDIvol. This method does not account for how tin filtration affects patient organ and effective dose. Purpose: To investigate the effect of tin filtration on patient organ and effective dose for CT Lung Cancer Screening (LCS) and CT Colonography (CTC). Methods: A previously‐developed Monte Carlo program was adapted to model a 96‐row CT scanner (Somatom Force, Siemens Healthineers) with tin filtration capabilities at 100 kV (100Sn) and 150 kV (150Sn). The program was then validated using experimental CTDIvol measurements at all available kV (70–150 kV) and tin‐filtered kV options (100Sn and 150Sn). After validation, the program simulated LCS scans of the chest and CTC scan of the abdomen‐pelvis for a population of 53 computational patient models from the extended cardiac‐torso family. Each scan was performed using three different spectra: 120 kV, 100Sn, and 150Sn. CTDIvol‐normalized organ doses and DLP‐normalized effective doses, commonly referred to as dose conversion factors, were compared between the different spectra. Results: For all LCS and CTC scans, CTDIvol‐normalized organ doses and DLP‐normalized effective doses increased with increasing beam hardness (120 kV, 100Sn, 150 Sn). For LCS, relative for 120 kV, conversion factors for 100Sn produced a median increase in effective dose of 9%, with organ dose increases of 8% to lung, 5% to breast, 15% to thyroid, and 3% to skin. Conversion factors for 150Sn produced a median increase in effective dose of 20%, with organ dose increases of 16%, 18%, 26%, and 12% to these same organs, respectively. For CTC, relative for 120 kV, conversion factors for 100Sn produced a median increase in effective dose of 12%, with organ dose increases of 9% to colon, 10% to liver, 11% to stomach, and 4% to skin. Conversion factors for 150Sn produced a median increase in effective dose of 21%, with organ dose increases of 16%, 17%, 19%, and 10% to these same organs, respectively. Conclusions: Results show that dose conversion factors are greater when using tin filtration and should be considered when evaluating tin's potential for dose reduction. [ABSTRACT FROM AUTHOR]

Background: Inhaling radon is the most common way that humans are exposed to this radioactive gas. Radon can seep into buildings and homes, where it can accumulate to levels that can be harmful to human health. According to the World Health Organization, radon is the second most common cause of lung cancer. Materials and Methods: The radon concentrations, effective dosage and lung dose were assessed in construction building materials of sand, cement, and bricks in Al-Shatra City, Dhi-Qar Governorate, Iraq using solid state nuclear track detector CR-39. Results: The average radon concentrations in sand were 92.766 ± 46.518 Bqm-3, while in bricks was 198.256 ± 87.64 Bqm-3 and cement was 69.897±46.903 Bqm-3. According to this study, there was difference in the concentrations of radon, and the largest amount was found in the bricks. An annual effective dose was 2.34 mSvy-1, 4.99 mSvy-1 and 1.76 mSvy-1 for sand, bricks and cement, respectively. On the other hand, the lung dose was determined to be 3.71, 7.92 and 2.795 for sand, bricks and cement respectively. Conclusion: The concentrations of radon gas in building materials were consistent with recommended by the International Commission on Radiological Protection (ICRP) 200- 300 Bqm-3 except the bricks materials. [ABSTRACT FROM AUTHOR]

Background: This study was performed to assess pediatric dose reference level for routine computed tomography (CT) examination (head, chest and abdomen-pelvic) along with its corresponding risks in Great Khorasan province, Iran. Martial and Methods: For this purpose, different CT scan parameters of patients in 1-5, 6-10, and 11-15 years old were collected from 23 public hospitals. The total and main organ effective dose (ED), and DLP was estimated by Impact Dose software for each age group. In addition, the cancer risk of each CT examination was calculated according to the BEIR VII model and ICRP 103 data with PCMX software. Results: The results of the estimated values of dosimetric quantities indicated that the range of changes of these quantities is very wide (3 to almost 10 times) even in a certain age group. In common CT scans, the highest value for the average dose received by the patient was 27.14 mGy for the brain, 11.41 mGy for the lung, and 9.88 mGy for the bladder, respectively. Also the highest amount of REID in men and women are caused by abdominal-pelvic and breast CT scan, respectively. Conclusion: Although the values of studied quantities are not significantly different from similar reports, however, this does not reduce the important and necessity of the present study, as knowing the real amount dosimetric quantities in each area can help local authorities in revising and optimizing protocols to reduce patients' dose. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The objectives of this study were to explore the median effective dose (ED50) and the dose required for successful anesthesia in 95% of the patients (ED95) of remimazolam for intravenous anesthesia in adult outpatients undergoing gastroscopy. METHODS: This pilot study was conducted in patients scheduled to undergo painless gastroscopy at the authors' hospital between March 15, 2022 and March 25, 2022. The ED of remimazolam was determined using the modified Dixon sequential method, using an initial induction dose of 0.2 mg/kg. With successful or failed anesthesia, the remimazolam dose was decreased or increased by 0.05 mg/kg for the next patient, respectively. RESULTS: Twenty-two patients (43.6 ± 10.5 years of age) were enrolled. During gastroscopy, the remimazolam induction dose was 19.93 ± 2.96 mg (0.2-0.45 mg/kg). Eighteen patients could complete anesthesia with remimazolam alone, and four patients needed propofol to complete anesthesia. The induction time after the injection of remimazolam was 20.8 ± 8.4 s, the gastroscopy time was 5.1 ± 1.3 min, and the anesthesia recovery time was 17.5 ± 5.6 min. The ED50 and the ED95 of remimazolam were 0.362 mg/kg (95% confidence interval [CI]: 0.313-0.455 mg/kg) and 0.464 mg/kg (95% CI: 0.403-2.242 mg/kg), respectively. The vital signs of all patients remained within the predefined acceptable limits. No patients required antagonist rescue. CONCLUSION: The ED50 and ED95 of remimazolam for adult gastroscopy were 0.362 mg/kg and 0.464 mg/kg, respectively. Additional anesthetics might be required during gastroscopy in some patients. TRIAL REGISTRATION: The trial was registered. The number is ChiCTR2200057446. [ABSTRACT FROM AUTHOR]

This study aimed to investigate and compare the effective dose (ED) delivered by computed tomography (CT) in whole-body positron emission tomography/CT (WB-PET/CT) scans between patients positioned with their arms-raised and those with their arms-lowered during the scan on a large population. The retrospective study involved 785 oncology patients who underwent WB-PET/CT scans with 18F-FDG between January and June 2019. Exclusion criteria were applied, resulting in a final analysis of data from 732 adult patients. All of the patients were measured height and weight, and the ED from CT in WB-PET/CT was estimated using the dose length product value and a conversion factor. Statistical analyses were conducted to explore relationships between factors and the ED. Linear regression analysis was performed to investigate connections between weight and ED, and height and ED. Multiple linear regression was used to predict ED based on sex, weight, and arm position. The arm-lowered group had a higher ED than the arm-raised group, and the median dose was 1.1 times higher in the arm-lowered group. The difference in ED between the two groups was found to be greater with higher body weight. Arm-position (β = 0.460), sex (β = −0.190), and weight (β = 0.057) were significant predictors of ED. This study demonstrated that arm position, sex, and weight were significant factors influencing the ED from CT scans in WB-PET/CT. The research underscores the importance of considering these factors when evaluating radiation exposure in clinical practice, particularly for patients undergoing WB-CT imaging. These findings contribute to a better understanding of the radiation dosimetry associated with different patient positions during WB-PET/CT scans. [ABSTRACT FROM AUTHOR]

The aim of this study was to experimentally measure organ doses for computed tomography (CT) procedures using thermoluminescence dosimeters (TLDs) on a RANDO anthropomorphic phantom and verify the measured doses using CT-Expo software. The phantom was irradiated using clinical CT scan protocols routinely used for specific procedures in the radiology department. Fifty TLD chips were used in this study. The scanning parameters (kVp, mA, s) used to scan the phantom were used as input parameters for CT-Expo dose estimations. The TLD measured organ doses varied between 3.97 mGy for the esophagus and 56.22 mGy for the brain. High doses were recorded in the brain (37.80–56.22 mGy) and the eye lens (29.94–36.16 mGy). Comparing the organ dose measurements between TLD and CT-Expo, the maximum organ dose difference was obtained for the eye lens. A comparison between the two methods for the other organs were all less than 32 %. The effective doses from the TLD measurements for the head, chest, and abdominopelvic CT examinations were 2.78, 6.67, and 17 mSv, respectively and CT-Expo were 2.20, 10.30, and 16.70 mSv, respectively. The experimental and computational results are comparable, and the reliability of the TLD measurements and CT-Expo dose calculator has been proven. A reason for the difference in dose measurements between the two methods has been attributed to the dissimilarity in the organ position in the Rando anthropomorphic phantom and the standard mathematical phantom used by CT-Expo. The experimental and computational results have been found to be comparable. [ABSTRACT FROM AUTHOR]

Background: The number of fluoroscopically guided interventions (FGI) has increased significantly over time. However, little attention has been paid to possible stochastic radiation effects. The aim of this retrospective study was to investigate the number of patients who received cumulative effective doses over 100 mSv during FGI procedures. Material and Methods: Five thousand five hundred and fifty four classified FGI procedures were included. Radiation dose data, retrieved from an in-house-dose-management system, was analysed. Effective doses and cumulative effective doses (CED) were calculated. Patients who received a CED > 100 mSv were identified. Radiology reports, patient age, imaging and clinical data of these patients were used to identify reasons for CED ≥ 100 mSv. Results: One Hundred and thirty two (41.1% female) of 3981 patients received a CED > 100 mSy, with a mean CED of 173.5 ± 84.5 mSv. Mean age at first intervention was 66.1 ± 11.7 years. 81 (61.4%) of 132 were older than 64 years, one patient was < 30 years. 110 patients received ≥ 100 mSv within one year (83.4%), through FGIs: EVAR, pelvic/mesenteric interventions (stent or embolization), hepatic interventions (chemoembolization, TIPSS), embolization of cerebral aneurysms or arterio-venous-malformations. Conclusions: Substantial CED may occur in a small but not ignorable fraction of patients (~ 3%) undergoing FGIs. Approximately 2/3rd of patients may most likely not encounter radiation-related stochastic effects due to life-threatening diseases and age at first treatment > 65 years but 1/3rd may. Patients undergoing more than one FGI (77%) carry a higher risk of accumulating effective doses > 100 mSv. Remarkably, 23% received a mean CED 162.2 ± 72.3 mSv in a single procedure. [ABSTRACT FROM AUTHOR]

The effective dose (ED) in computed tomography (CT) may be calculated by multiplying the dose–length product (DLP) by a conversion factor. As children grow, automatic exposure control increases the DLP, while the conversion factor decreases; these two changes affect the ED in opposite ways. The aim of this study was to investigate the methods of ED estimation according to age in pediatric brain CT. We retrospectively analyzed 980 brain CT scans performed for various clinical indications in children. The conversion factor at each age, in integer years, was determined based on the values at 0, 1, 5, and 10 years provided by the International Commission on Radiological Protection (ICRP), using a curve (curve method) or lines (linear method). In the simple method, the ED was estimated using the ICRP conversion factor for the closest age. We also analyzed the ED estimated by a radiation dose management system. Although the median DLP at each age increased with age, the median ED estimated by the curve method was highest at 0 years, decreased with age, and then plateaued at 9 years. The linear method yielded mildly different results, especially at 2 and 3 years. The ED estimated by the simple method or the radiation dose management system showed inconsistent, up-and-down changes with age. In conclusion, the ED in pediatric brain CT decreases with age despite increased DLP. Determination of the conversion factor at each age using a curve is expected to contribute to estimating the ED in pediatric CT according to age. [ABSTRACT FROM AUTHOR]

Copyright of Iranian Plant Protection Research is the property of Ferdowsi University of Mashhad Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Potential risk associated with low‐dose radiation exposures is often expressed using the effective dose (E) quantity. Other risk‐related quantities have been proposed as alternatives. The recently introduced risk index (RI) shares similarities with E but expands the metric to incorporate medical imaging‐appropriate risks factors including patient‐specific size, age, and sex. Purpose: The aim of this work is to examine the RI metric for quantifying stochastic radiation risk and demonstrate its applications in nuclear imaging. The advantages in this improved metric may help the field progress toward stratified risk consideration in the course of patient management, improve efforts for procedure optimization, and support an evolution in the science of radiation risk assessment. Methods: In this study we describe, implement, and calculate RI for various diagnostic nuclear imaging scenarios using reference biokinetics published in ICRP Publication 128 for commonly utilized radiopharmaceuticals. All absorbed dose, E and RI calculations were performed using the freely available MIRDcalc nuclear medicine dosimetry software; the organ specific risk parameters used in the software are also benchmarked in this text. The resulting RI and E values are compared and various trends in RI values identified. Results: E and RI coefficients were calculated for 3016 use cases. Notably RI values vary depending on patient characteristics. Overall, across the population, global trends in RI values can be identified. In general, RI values were 2.15 times higher for females than males, due to higher risk coefficients and activities being distributed in smaller reference masses. The pediatric patients showed higher RIs than adults, as younger patients generally receive higher absorbed doses per administered activity, and are more radiosensitive, and have a longer projected lifespan at risk. A compendium of E and RI values is also provided in table format to serve as a reference for the community. Conclusions: RI is a rational quantity that could be used for justification, risk communication and protocol optimization in medical imaging. It has some advantages when compared to the long‐utilized E value with respect to personalization, since accounts for patient size, age, sex, and natural incidence of cancer risk. [ABSTRACT FROM AUTHOR]

The objective of the study was to estimate the effective dose rates of external population exposure based on measurements of average specific activity of natural radionuclides (226Ra, 232Th and 40K) in building materials of existing buildings. The measurements were performed using new developed non-destructive technique in 100 apartments in 9 Russian cities. The effective dose rate is 34 nSv h–1 in average and varies from 10 to 102 nSv h–1 between cities. Specific factors of conversion from specific activity to effective dose rate were obtained taking into account the real room geometries. [ABSTRACT FROM AUTHOR]

The paper presents the results of radiocarbon (14C) concentration measurements in tree rings in the vicinity of Kursk NPP (Russia) with four operating RBMK reactors. The sampling was carried out from the site with the highest expected accumulation of radiocarbon in vegetation. The site was determined with long-term meteorological data. The measurements of 14C concentration carried out with accelerator-mass spectrometer in Budker Institute of Nuclear Physics, Novosibirsk, Russia. The obtained results demonstrated the influence of exploitation of Kursk NPP to the concentration of 14C in tree rings. Based on the equilibrium between the 14C ratio in the tree rings and the surrounding air, retrospective estimates of the radiocarbon discharge and effective doses were made. Effective doses were calculated with two approaches: IAEA methodology and less conservative approach, considering the real food consumption in the Kursk region. The values of calculated doses by the second method (0.08–2.58 μSv) are more than 2 times less than IAEA approach (0.17–5.30 μSv). The highest difference between measured and background 14C in tree ring is 41.7 ± 5.8 pMC in 2014 during the restoration of graphite stack. The main contribution to 14С exposure in the considering period is caused by background – from 70 to 99%. [ABSTRACT FROM AUTHOR]

We propose a novel method for calculating the effective dose that closely reflects the individual attenuation, utilizing two conversion coefficients. A total of 180 adult patients who underwent abdomen–pelvis computed tomography were categorized into six groups based on sex and body type. The effective dose was calculated by multiplying the dose-length product with the effective dose conversion coefficient and the size-specific dose estimate conversion factor. The effective dose calculated using a simulation-based dose calculator (WAZA-ARI) was employed as the reference value. The following values, obtained through both methods, were compared within each category: distribution of the effective dose, median effective dose, and relative difference in median effective dose across additional body mass index (BMI) categories. For male patients, no significant disparity was observed in the median effective doses calculated using the two methods. The relative differences in median effective doses across additional BMI categories ranged from – 5 to 6%. Conversely, among female patients, the median effective dose calculated using our method slightly undercut that calculated using WAZA-ARI, with relative differences ranging from – 16 to – 9%. Additionally, relative differences in median effective dose across additional BMI categories ranged from – 18 to – 7%. The median effective dose differed slightly depending on the calculation method because of the different reference phantoms applied in dose calculations. Our proposed method is sensitive to individual size and helps compute a size-specific effective dose. [ABSTRACT FROM AUTHOR]

The objective of this work is to give a holistic overview of the groundwater quality in Qatar in terms of its radon levels and provide a radiological risk assessment of elevated radon levels on human health. This study covered the analysis of groundwater collected from various locations throughout Qatar and maps using ArcGIS followed by a radiological risk assessment of radon in Qatar. There is no extensive study reported to investigate radon activity levels in groundwater across Qatar and their health effects. The radon level measurements of the Qatari groundwater ranged between 2.7 ± 0.2 and 60.7 ± 13.4 Bq/L with a mean value of 20.6 Bq/L, which is greater than the US EPA's maximum contamination level (11 Bq/L). About 65% of the studied samples exceeded the US EPA's MCL guidelines. The mean total annual effective dose due to radon inhalation and ingestion was 0.056 mSv/y, which is below the WHO reference level of 0.1 mSv/y. The radon radiological risk study through inhalation and ingestion clearly revealed that the contribution of the inhalation dose was higher than the ingestion dose. [ABSTRACT FROM AUTHOR]

Accurate knowledge of the terrestrial radionuclides concentrations in building components is crucial for radiation exposure assessment to the dwellers. The present investigation determines the natural radioactivity levels in common building materials (the structural and decorative) used in Bangladeshi dwellings via HPGe gamma-ray spectrometry. The measured activity levels of 226Ra, 232Th and 40K in the studied materials ranged between 7.33 ± 3.49 and 157.13 ± 13.03 Bq kg−1, 4.08 ± 1.84 and 131.65 ± 6.87 Bq kg−1 and 128.38 ± 10.27 and 1234.5 ± 39.77 Bq kg−1, respectively. Majority of the studied materials, especially the cement and paint, show the elevated concentrations of terrestrial radionuclides. However, for most of the samples, the total activity in terms of hazardous radium, show lower values compared to the OECD reported limiting index of 370 Bq kg−1, except in paint samples. The potential radiological hazards owing to the investigated samples were assessed by calculating a number established screening parameters, and compared with the agreed limits set by international regulatory bodies. The calculated indoor and outdoor absorbed dose rates for most of the materials (apart from sand) overdo the agreeing limiting standards of 84 and 59 nGy h−1, as suggested by UNSCEAR (2000). Therefore, continuous radiation level monitoring, especially for paint and cement samples, need to be continued to avoid undesirable exposure from radiation to occupants. Overall, the calculated data may help to set up recommendations for using building materials for dwelling resolutions. [ABSTRACT FROM AUTHOR]

BACKGROUND: X-ray Computed Tomography dose levels have been varying among modalities and scanning body regions due to the absence of incessant routine follow-up. Thus, the study aimed to compute the dose index discrepancies in Ethiopia for the most recurring scan protocols (head, chest, abdomen, and pelvis). METHODS: A purposive sampling method was employed to select the hospitals due to the rare existence of functional CT scanners in Ethiopia. From the selected hospitals, a total of 1,385 (249 heads, 804 chests, 132 abdomens, and 200 pelvis) were collected in terms of standard dose metric values in the period of December 2019-March 2020. Patients' DLP was computed into mean value using IBM SPSS Statistics 20 software. From the mean DLP, we can compute the effective dose. RESULTS: Patients' dose level disparity was observed in this study though it is below the ICRP standard level for all body regions except for pelvis DLP (593.37 mGy-cm) at Black Lion. The dose level for the head and chest are computed within the recommended level at all hospitals. Effective doses for the pelvis at four hospitals (Teklehaimanot, Black Lion, ALERT, Paul's, and Ayder hospitals) were computed as 6.45, 8.90, 5.08, 6.54, and 6.84 mSv respectively, and the effective doses for abdomen at Ayder Hospital was obtained to be 8.90 mSv, which is above the recommended value. CONCLUSION: X-ray CT scanners are somewhat properly functioning although some sort of justification and optimization for pelvis and abdomen examinations are strongly recommended to implement as low as reasonably achievable principle. [ABSTRACT FROM AUTHOR]

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About 75% of the information humans receive visually or through the eyes. However, the eye cannot detect all types of light, including X-ray radiation. There are parts of the human body organs are very sensitive to Xray radiation, because of the risk of damaging tissues and triggering causing ery, infertility or cataracts. Today, X-rays have become the backbone of the development of radiology equipment, especially for producing. One of them is C-Arm equipment technology, which is able to image three-dimensional patient objects in real time with fluoroscopy techniques. This study aims to obtain and evaluate the effective radiation dose received by medical personnel working in the cathlab room area when radiation workers during cardiac catheterization is performed. The results show operator area; the effective dose received was 0.000 mSv, doctors ranged from 1.136 to 3.608 mSv, while nurses ranged from 0.194 mSv to 2.270 mSv, while radiographers ranged from 0.074 mSv to 0.126 mSv, while patient entrance and exit areas ranged from 0.00 mSv to 0.0127 mSv, while nurses in and out of medical personnel ranged from 0.005 mSv to 0.057 mSv, Measurements on the floor near the radiation source/floroscopy range from 0.036 mSv to 0.074 mSv. Cathlab indoor wall measurement results range from 0.031 mSv to 0.103 mSv. Within 1 year, the dose in the operator room is 0.00 mSv, the dose received by doctors ranges from 230.4 to 1209.5 mSv/hour, radiographers between 128.2 mSv to 1812.4 mSv and nurses between 115.2 mSv to 2448.2 mSv. In the area of the patient entrance and exit between 0.00 mSv to 38.8 mSv, the area of the patient entrance and exit between 72.00 mSv to 82.2 mSv, and the floor area near the radiation source/floroscopy between 518.2 mSv to 1065.2 mSv, as well as the inner wall area of the cathlab chamber between 44.6 mSv to 148.32 mSv. It was found that; The effective dose received in one year received by doctors, nurses and radiographers who work close to radiation sources (floroscopy) results are higher than the dose value set by PERKA BAPETEN No. 8 of 2011 which is 20 mSv and ICRP 203 which is 500 mSv per year. [ABSTRACT FROM AUTHOR]

Introduction: Radioactive contamination by uranium and its emissions, such as alpha particles, is considered one of the most critical issues affecting the human race and its existence. The study investigated the high ionization capacity number of alpha particles in whole blood samples from cancer patients because these particles have the most significant impact on the shape and function of living cells, modifying them into malignancies. Material and Methods: The TASLImage solid nuclear trace detector CR-39 was used to measure the effects of alpha emitters in the whole blood samples from 40 cancer patients for five types of cancer (breast, uterus, prostate, kidney, and colon) collected from a government hospital at Karbala/Iraq and compared with ten healthy samples. Moreover, the research investigated whether smoking and gender variation affect the outcomes. Results: The radon concentration in whole blood samples from patients and healthy individuals was significantly different (p< 0.05), and it was slightly higher in males with (22.82254±7.38794 Bq/m3). Women with colon cancer had higher blood levels of radon (32.13787±5.79261 Bq/m3) than men with the same malignancy (18.80531±5.63747 Bq/m3), regardless of gender. While the age factor had no noticeable impact, the smoking element had a considerable effect (p< 0.05). Conclusion: All alpha levels were within the (ICRP) usual ranges. Women with colon cancer had the most significant alpha values. In contrast, men with the same disease had the lowest values despite cancer patients' blood levels being higher than those of the healthy group.