Radiation Dose Levels Research Articles

Technical Note: Quality assessment of virtual monochromatic spectral images on a dual energy CT scanner

To assess the quality of images obtained on a dual energy computed tomography (CT) scanner. Image quality was assessed on a 64 detector-row fast kVp-switching dual energy CT scanner (Revolution GSI, GE Medical Systems). The Catphan phantom and a low contrast resolution phantom were employed. Acquisitions were performed at eight different radiation dose levels that ranged from 9mGy to 32mGy. Virtual monochromatic spectral images (VMI) were reconstructed in the 40-140keV range using all available kernels and iterative reconstruction (IR) at four different blending levels. Modulation Transfer Function (MTF) curves, image noise, image contrast, noise power spectrum and contrast to noise ratio were assessed. In-plane spatial resolution at the 10% of the MTF curve was 0.60mm-1. In-plane spatial resolution was not modified with VMI energy and IR blending level. Image noise was reduced from 16.6 at 9mGy to 6.7 at 32mGy, while peak frequency remained within 0.14±0.01mm-1. Image noise was reduced from 14.3 at IR 10% to 11.5 at IR 50% at a constant peak frequency. The lowest image noise and maximum peak frequency were recorded at 70keV. Our results have shown how objective image quality is varied when different levels of radiation dose and different settings in IR are applied. These results provide CT operators an in depth understanding of the imaging performance characteristics in dual energy CT.

Raman and Fluorescence Profiles Modifications of Muscular and Adipose Tissues Exposed to Low Energy X-ray Beams.

This work aims to investigate changes induced by low-energy radiation in adipose and muscular tissues employing autofluorescence and Raman spectroscopic techniques. X-ray beams expositions with 25 and 35 kV at 0.11, 1.1, and 2.1 Gy radiation dose levels were applied. Changes in Raman line intensities at specific bands assigned to collagen, proteins, and lipids were observed. Autofluorescent analysis exhibit variations in the collagen and nicotinamide adenine dinucleotide emission (NADH), resulting from the structural modifications, variations on the reduced/oxidized fluorophores equilibrium followed by radiation exposure. Results show that Raman and fluorescence spectroscopy are suitable techniques to evaluate radiation effects on biomolecules even at low radiation doses and energies.

Sexual organ-sparing with hydrogel spacer injections for rectal cancer radiotherapy: a feasibility pilot study.

The aim of this pilot study was to investigate in two rectal cancer patients undergoing neoadjuvant chemo-radiotherapy (nCRT) the implant feasibility and dosimetric benefit in sexual organ-sparing of an injectable, absorbable, radiopaque hydrogel spacer. Two rectal cancer patients (one male and one female) underwent hydrogel implant between rectum and vagina/prostate before nCRT and curative surgery. A CT scan was performed before and after injection and a comparative dosimetric study was performed testing a standard (45/50 Gy) and a dose escalated (46/55.2 Gy) schedule. In both patients, the spacer implant in the recto-prostatic or recto-vaginal space was feasible and well tolerated. For the male, the dosimetric benefit with spacer was minimal for sexual organs. For the female however, doses delivered to the vagina were significantly reduced with spacer with a mean reduction of more than 5 Gy for both regimens. For organ preservation protocols and selected sexually active female patients, use of hydrogel spacers can be considered to spare sexual organs from the high radiotherapy dose levels. For females with advanced rectal tumor, a spacer implant between the rectum and the vagina before nCRT is feasible and reduces doses delivered to the vagina.

Spectral CT quantification stability and accuracy for pediatric patients: A phantom study.

BackgroundSpectral computed tomography (spectral CT) provides access to clinically relevant measures of endogenous and exogenous materials in patients. For pediatric patients, current spectral CT applications include lesion characterization, quantitative vascular imaging, assessments of tumor response to treatment, and more.ObjectiveThe aim of this study is a comprehensive investigation of the accuracy and stability of spectral quantifications from a spectral detector‐based CT system with respect to different patient sizes and radiation dose levels relevant for the pediatric population.Materials and methodsA spectral CT phantom with tissue‐mimicking materials and iodine concentrations relevant for pediatric imaging was scanned on a spectral detector CT system using a standard pediatric abdominal protocol at 100%, 67%, 33% and 10% of the nominal radiation dose level. Different pediatric patient sizes were simulated using supplemental 3D‐printed extension rings. Virtual mono‐energetic, iodine density, effective atomic number, and electron density results were analyzed for stability with respect to radiation dose and patient size.ResultsCompared to conventional CT imaging, a pronounced improvement in the stability of attenuation measurements across patient size was observed when using virtual mono‐energetic images. Iodine densities were within 0.1 mg/ml, effective atomic numbers were within 0.26 atomic numbers and electron density quantifications were within ±1.0% of their respective nominal values. Relative to the nominal dose clinical protocol, differences in attenuation of all tissue‐mimicking materials were maintained below 1.6 HU for a 33% dose reduction, below 2.7 HU for a 67% dose reduction and below 3.7 HU for a 90% dose reduction, for all virtual mono‐energetic energies equal to or greater than 50 keV. Iodine, and effective atomic number quantifications were stable to within 0.1 mg/ml and 0.06 atomic numbers, respectively, across all measured dose levels.ConclusionSpectral CT provides accurate and stable material quantification with respect to radiation dose reduction (up to 90%) and differing pediatric patient size. The observed consistency is an important step towards quantitative pediatric imaging at low radiation exposure levels.

DaNet: dose-aware network embedded with dose-level estimation for low-dose CT imaging

Many deep learning (DL)-based image restoration methods for low-dose CT (LDCT) problems directly employ the end-to-end networks on low-dose training data without considering dose differences. However, the radiation dose difference has a great impact on the ultimate results, and lower doses increase the difficulty of restoration. Moreover, there is increasing demand to design and estimate acceptable scanning doses for patients in clinical practice, necessitating dose-aware networks embedded with adaptive dose estimation. In this paper, we consider these dose differences of input LDCT images and propose an adaptive dose-aware network. First, considering a large dose distribution range for simulation convenience, we coarsely define five dose levels in advance as lowest, lower, mild, higher and highest radiation dose levels. Instead of directly building the end-to-end mapping function between LDCT images and high-dose CT counterparts, the dose level is primarily estimated in the first stage. In the second stage, the adaptively learned low-dose level is used to guide the image restoration process as the pattern of prior information through the channel feature transform. We conduct experiments on a simulated dataset based on original high dose parts of American Association of Physicists in Medicine challenge datasets from the Mayo Clinic. Ablation studies validate the effectiveness of the dose-level estimation, and the experimental results show that our method is superior to several other DL-based methods. Specifically, our method provides obviously better performance in terms of the peak signal-to-noise ratio and visual quality reflected in subjective scores. Due to the dual-stage process, our method may suffer limitations under more parameters and coarse dose-level definitions, and thus, further improvements in clinical practical applications with different CT equipment vendors are planned in future work.

Assessment of the image quality of virtual monochromatic spectral computed tomography images: a phantom study considering object contrast, radiation dose, and frequency characteristics.

Fast kilovoltage (kVp)-switching technology cannot obtain conventional 120kVp images; thus, 70keV virtual monochromatic spectral computed tomography (CT) images (VMSI) are generally used. The contrast-to-noise ratio (CNR) is used to evaluate the image quality of VMSI; however, CNR does not include frequency characteristics. The present study aimed to investigate the evaluation methods of VMSI considering frequency characteristics by comparing the image quality of 70keV VMSI with that of conventional 120kVp images. The evaluated object contrasts were 70 and 300 Hounsfield units (HU). Scans used two radiation dose levels: low (LD) and standard (SD). The volume CT dose index of LD and SD was 4.8- and 12mGy, respectively. Images were reconstructed by filtered back projection, evaluating CNR, noise power spectrum (NPS), task transfer function (TTF), and system performance (SP) function calculated as TTF2/ NPS. The total NPS values (spatial frequency range: 0.2 ~ 0.4mm-1) of 70keV VMSI were higher than those of 120kVp images. The spatial frequency TTF values that reached 10% (f10%) of the 70keV VMSI changed based on object contrast. For the low-contrast condition, a lower f10% was observed with 70keV VMSI. The CNR of 70keV VMSI was comparable to that of 120kVp images in low- and high-contrast conditions. However, for 70keV VMSI, SP of low-contrast was low, and SP of high-contrast was high, compared with those of 120kVp images. This study suggested that only CNR was not sufficient to evaluate the image quality of VMSI; thus, evaluation methods considering frequency characteristics should be used.

Radiation Dose Level and Biological Effect Toward Human Being

Ionizing radiation is emitted from the result of radioactive materials. The scientific regular measure of dose was quantified according to the exposure of radiation to ward human being. The aim of the study was assessing the amount of dose level and its consequence that effect toward human being. The importance of this work was judged based on how much was questioned and the path ahead for people to defend themselves from radiation exposure. The present work was conducted by using gamma spectroscopy to determine the radiation dose level of ionizing radiation. It was checked of quantification dose which incorporates the total amount of ionizing radiation that is associated with damage the tissue. It was determined that absorbed and Annual equivalent dose of natural occurrence of radioactive material. All human being are exposed to ionizing radiation with natural cosmic rays coming from outer space and image therapy within in hospital. When it seen that the exposures were varied as of people immunity. The sources of radiation exposures to the human were estimated based on the dose which affects the organ. Radiation exposed was leads serious gene and cancer disease. Generally, in this survey we assessed that particularly ionizing radiation caused damaged short and long term effect.

Awareness of Source of Radiation, Its Hazards and Protection among Final Year MBBS Students: A Cross-sectional Observational Study

Introduction: Increase availability of multi-detector high speed CT scan, digital radiography and various image guided interventional procedures has increased the total number of radiation related examinations in current era. These have lead to increase radiation exposure to patients as well as the radiologist. This situation has raised the concern about the potential side effects to patients, like radiation-related cancer and death. Aim: Evaluation of awareness of source of radiation, radiation hazards and radiation protection among final year medical students in Tertiary Care Medical College Hospital. Materials and Methods: This was a cross-sectional observational type of study in which total 136 final MBBS students were issued a questionnaire consisting of 12 multiple choice questions including demographic data, awareness about source of radiation, radiation hazard, protection issues and knowledge about radiation dose levels of common radiological examinations. All questions were multiple choice types with answers containing 2 to 9 choices having only one correct answer. The questionnaire was prepared by authors and their answers were validated by various faculties of Department of Radiodiagnosis by peer review methods. This questionnaire was given in a physical form. The obtained data were analysed using statistical software (descriptive statistics used). As homogenous group of final year medical students were analysed, no scoring and no statistical test were needed. Results: In present study 87.5 % (n=119) of students considered radiation knowledge important for them. Out of eight specific questions for checking their knowledge about radiation awareness, five questions were regarding safe radiation practice, radiation exposure, and radiation dose in common and radiological examination. Among these questions “Rule of 10”- question was correctly answered by 113 (83.1%) of students. Questions regarding “Radiological examination of pregnant patient”- was correctly answered by 114 (83.8 %) of students and “Radiation exposure to patients during diagnostic radiology” question was correctly answered by 115 (84.6%) of students. Conclusion: Medical students have good awareness about radiation protection, with a specific gap of knowledge concerning source of radiation, biological effect of radiation and radiation hazards. Undergraduate teaching curriculum must include comprehensive knowledge about radiation hazards and radiation safety.

The Radiation Effect on Low Noise Amplifier Implemented in the Space-Aerial–Terrestrial Integrated 5G Networks

This paper provides the details of a study on the effects of electron irradiation on two Low Noise Amplifiers (LNA), the Gallium-Arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) based and the Silicon-Germanium (SiGe) Heterojunction Bipolar Transistor (HBT)-based. Previous studies have shown that the properties of GaAs and SiGe HBT's are very tolerant of gamma, neutron, and proton irradiation without additional radiation hardening. Nowadays, commercials on the shelves (COTS) LNAs have been used in CubeSat space communication systems which may be connected to other communication networks for the implementation of the space-aerial- terrestrial integrated 5G network (SATIN) systems projects, for satellites, launched into Low and Medium Earth Orbits. Previous studies suggest that the electron radiation in space may degrade the LNAs' performance and might even lead to its failure. Located at the front end of the communication receiver system, this paper conducted such investigation to evaluate the performance under the radiation of the GaAs and SiGe LNAs considering the physics of the technology of each LNA, respectively. The results indicate that both SiGe and GaAs technologies are affected after electron irradiation. As a result, this degradation of the LNAs' performance affected the communications system performance of the inter-satellite radio link. After the assessment of the quality performance of the communication link at the system level, it has been found that the inter-satellite space link will be at risk under high space radiation dose and the link BER degrades proportionally to the radiation dose level.

Assessment of Ionizing Radiation Dose and Risk Levels associated with Radioactivity in Oraifite, Nigeria.

Radioactivity has been natural occurrence in human environment and its adverse effects are highly undesirable. This study assessed radiation risk levels associated with radioactivity in Oraifite using gamma ray (Ɣ-ray) spectrometry and radiation survey meter. The mean value of background ionizing radiation (BIR) exposure rate ranged from 0.011 to 0.014mRh-1. The mean activities of 226Ra, 232Th, 40K ranged from 23.54±4.89 to 41.03±4.28 BqKg-1, 9.69±1.88 to 11.34±1.86 BqKg-1, 419.22±3.41 to 737.91±4.78 BqKg-1 respectively. Mean values of radium equivalent (Raeq), absorbed dose (D), Igamma (IƔ),  internal hazard index (Hin), external hazard index (Hex) and annual effective dose equivalent (AEDE), were 60.05Bqkg-1, 55.75nGh-1, 0.86, 0.41, 0.30 and 0.07mSvy-1 respectively. Excess lifetime cancer risk (ELCR) which is estimation of the probability of cancer incidence in a population of individuals for a specific lifetime had a mean value of 0.25x10-3 and this is lower than the world permissible limit of 0.29x10-3. The average dose to human organs/tissues; lungs, ovaries, bone marrow, testes, kidney, liver and whole body were 0.033, 0.028, 0.033, 0.040, 0.028, 0.023, and 0.033 mSvy-1 respectively, meaning that all the computed organ dose were far much lower than the maximum allowable standard value of 1.0 mSvy-1. Virtually all hazard indices were below the ICRP recommended values and in general the residents of Oraifite are not under ionizing radiation threat.

Assessment of radiological hazards in the phosphate mining area of Kpogamé, Togo

Radioactive elements of natural origin are present everywhere in the environment as well as sediments in different concentrations depending on the local geology of soil. These elements are hazardous to the environment and to human health. This present work studied the radioactivity of a set of soil samples of phosphates tailings collected from a mining site in Kpogamé with a view to assessing the radiological hazards. Collected soil samples were analyzed at the Jožef Stefan Institute lab using high purity germanium detector, and radiological parameters such as radium equivalent, absorbed dose rate, indoor and outdoor annual effective dose rates, internal and external hazards indices, Gamma radiation representative level index and excess lifetime cancer risk for outdoor exposure were deducted. Higher values of activity concentrations were found for certain samples (values reaching 319.3 and 57.9 Bq/kg for Ra-226 and Th-232) when compared to UNSCEAR values. Higher values of these radiological parameters were also obtained when compared to the recommended limit and worldwide values (for example the maximum value of 176.10 ​nGy/h obtained for the absorbed dose rate was more than twice higher the worldwide average value of 84 ​nGy/h). Overall, five locations showed values above the norm. These locations have high values of excess lifetime cancer risk for outdoor exposure (0.3115×10-3 – 0.7525×10-3). The implication of these results is that there are locations around Kpogamé phosphate mining area with high probability of getting cancer from ionizing radiation associated to the environmental geology. Therefore, it is recommended to optimize the way to extract ores and avoid public to access the mining sites without knowing the level of radiation dose in this area.

Chemical compositions and biological activities of the essential oils from gamma irradiated celery (Apium graveolens L.) seeds

Celery seed oils can help in detoxification processes of the body as it facilitates the elimination of toxins and other harmful substances out of the body. This study aimed to assess biological activity of essential oils extracted from un-irradiated and irradiated celery seeds by gamma rays. Celery seeds were irradiated with different dose levels of gamma radiation; control, 2.5, 5.0, and 10.0 kGy. The highest increase of essential oil extracted was registered with a dosage level of 10.0 kGy (2.42%). The GC-MS analysis showed that, there were new compounds detected in the irradiated samples and others compounds were increased or decreased. The FTIR spectra showed alterations in functional groups of essential oils extracted from celery seeds upon gamma-irradiation. Total phenols, total flavonoids and antioxidant activity increased proportional to the increase in the irradiation dose level and the maximum increase obtained in the irradiation dose level 10.0 kGy. This may be an evidence on the biological value, there were anticancer activity against 2 cell lines, breast cancer cell line (MCF-7) and lung cancer cell line (A549). The best IC50 in A549 was 145 µg/ml in sample with irradiation dose level 5.0 kGy while the best IC50 in MCF-7 was 124 µg/ml in irradiated sample with dose 5.0 kGy. Also, the highest inhibition zone of S. aureus, B. subtilis and K. pneumoniae were obtained with the oil extracted from seeds irradiated with 5 kGy dose level, where E. coli and C. albicans were more pronounced for the oil gotten from the seeds irradiated with 10.0 kGy. The irradiation process for celery seeds may be promising for biological value of celery oils.

Quantitative positron emission tomography imaging in the presence of iodinated contrast media using electron density quantifications from dual-energy computed tomography.

As preparation for future positron emission tomography (PET)/dual-energy computed tomography (DECT)T imaging modality and new possible clinical applications, the study aimed to evaluate the utility of clinically available spectral results from a DECT system for improving attenuation corrections of PET acquisitions in the presence of iodinated contrast media. The dependence of the accuracy of PET quantification values, reconstructed with conventional and spectral-based attenuation corrections, was examined as a function of the amount of iodine content and x-ray radiation exposure. Measurements were performed on commercial PET/CT and DECT systems, using a semi-anthropomorphic phantom with seven centrifuge tubes in its bore. Five different configurations of tube contents were scanned by both PET/CT and DECT. With the aim of mimicking clinically observed concentrations, in all phantom configurations the center tube contained a high concentration of radionuclide while the peripheral tubes contained a lower concentration of radionuclide. Iodine content was incrementally increased between phantom configurations by replacing iodine-free tubes with tubes that contained the original radionuclide concentration within a 10mg/ml iodine dilution. DECT-based attenuation correction maps were generated by scaling electron density spectral results into corresponding 511keV photon linear attenuation coefficients. Mean SUV values obtained from the nominal PET reconstruction, using conventional CT images as input for the attenuation correction, demonstrate a monotonic increase of 8.6% when the water and radionuclide mixtures were replaced by iodine, water, and radionuclide (same level of activity) mixture. Mean SUV values obtained from the DECT-based reconstruction, in which the attenuation correction utilizes electron density values as input, demonstrate different, more stable behavior across all iodine insert configurations, with a standard deviation to mean ratio of less than 1%. This observed behavior was independent of the area size used for measurement. A minor radiation dose dependency of the electron density values (below 0.5%) was observed. This resulted in consistent (iodine independent) PET quantification behavior, which persisted even at the lowest radiation dose levels tested in our experiment, that is, 25% of the radiation dose utilized for CT acquisition in the clinical PET/CT protocol. Utilization of DECT-generated electron density estimations for attenuation correction benefit PET quantification consistency in the presence of iodine and at nominal and low DECT radiation exposure levels. The ability to correctly account for iodinated contrast media in PET acquisitions will allow the development of new clinical applications that rely on the quantitative capabilities of spectral CT technologies and modern PET systems.

Variation in quality and acceptability of minimally processed garlic in response to γ-irradiation and packaging during refrigerated storage

In this study, the effect of different doses of gamma rays (0–2.5 kGy) and packages (polypropylene, perforated polypropylene, vacuum packages) on the acceptable shelf life of minimally processed garlic cloves was assessed under refrigerated conditions. It was observed that physiological loss in weight, firmness, total soluble solids, ascorbic acid, allicin content, colour (L, a, b, C, H, ΔE and BI) and total plate count varied significantly (p<0.05) with storage days and irradiation dose levels. Physiological loss in weight was significantly higher in vacuum packages and increased with storage duration. The total soluble solids increased, whereas, firmness decreased with storage period in both the irradiated and control minimally processed garlic cloves in all the packaging treatments. The total colour difference and browning index of irradiated minimally processed increased after storage. Ascorbic acid significantly decreased with storage and increased with higher irradiation dose levels whereas allicin content increased with increase in irradiation dose. Better microbial quality of minimally processed garlic cloves was maintained in unperforated polypropylene packages in both control and irradiated samples. Highest overall acceptability scores were obtained by garlic cloves irradiated @ 2.5 kGy irrespective of packages but quality parameters decreased to a lower value at this dose treatment. Thus, minimally processed garlic cloves maintained the best quality for 77 days in refrigerated storage (4 ± 1°C; 65 ± 5% RH) when these were irradiated with gamma rays @1.5 kGy after packaging in polypropylene packages of 150 gauge.

Inadequate object positioning and improvement of automatic exposure control system calculations based on an empirical algorithm.

When using automatic exposure control (AEC) systems in computed tomography (CT), miscalculation of tube current occurs when a patient is not aligned with the rotational center of the X-ray tube. A positioning compensation mechanism provides a corrective function when the patient is off-center; however, not all CT systems are equipped with this mechanism. AEC systems can broadly be divided into noise- and empirical-based. The authors studied empirical-based AEC systems to derive a compensation process to achieve an equivalent effect to that offered by the mechanism and to verify the accuracy of this process. A relational equation was derived to keep the tube current constant with variations in table height and quality reference milliampere-seconds (QRmAs), and this was adopted as the proposed compensation method. The radiation dose and image quality were evaluated for phantom imaging with and without the proposed compensation method using AEC and varying table heights. The output radiation dose and image quality were also evaluated for anthropomorphic chest phantom imaging to verify the compensatory effect of the proposed method. With the proposed compensation method, changes in the table height resulted in only small changes in the output radiation dose and noise level. Conversely, when the proposed compensation method was not used, changes in the table height resulted in widely varying output radiation dose and noise level. Imaging the anthropomorphic chest phantom with the proposed compensation method also yielded a stable output radiation dose.

Feasibility of imaging amyloid in the brain using small-angle x-ray scattering

Small-angle x-ray scattering (SAXS) imaging may have the potential to image β-amyloid plaques in vivo in the brain without tracers for assessment of Alzheimer’s disease (AD). We use a laboratory SAXS system for planar imaging of AD model and control mouse brains slices to detect regions with high density of amyloid plaques. These regions were validated with histology methods. Using Monte Carlo techniques, we simulate SAXS computed tomography (SAXS-CT) system to study the potential of selectively differentiating amyloid targets in mouse and human head phantoms with detailed anatomy. We found contrast between amyloid and brain tissue at small q (below 0.8 nm−1) in the neocortex region of the transgenic brain slices as supported by histology. We observed similar behavior through planar SAXS imaging of an amyloid-like fibril deposit with a 0.8 mm diameter at a known location on a wild type mouse brain. In our SAXS-CT simulations, we found that 33-keV x rays provide increase plaque visibility in the mouse head for targets of at least 0.1 mm in diameter, while in the human head, 70-keV x rays were capable of detecting plaques as small as 2 mm. To increase radiation efficiency, we used a weighted-sum image visualization approach allowing the dose deposited by 70-keV x rays per SAXS-CT slice of the human head to be reduced by a factor of 10 to 71 mGy for gray matter and 63 mGy for white matter. The findings suggest that a dedicated SAXS-CT system for in vivo amyloid imaging in small animals and humans can be successfully developed with further system optimization to detect regions with amyloid plaques in the brain with a safe level of radiation dose.

In-situ assessment of background gamma radiation dose levels in outdoor environment of Enugu urban areas, Enugu state, Nigeria

In this study, in-situ measurements of absorbed dose rates of background gamma radiation in 146 outdoor locations within Enugu urban areas were carried out by means of a hand held radiation survey meter equipped with Geiger-Muller tube. In order to assess the radiological health status of the studied environment, annual effective dose (AED) and excess lifetime cancer risk (ELCR) were estimated from the measured dose rates. The measured radiation dose rates across the locations ranged from 77.21 to 180.53 nGy h−1 with a mean value of 124.92 ± 2.00 nGy h−1. The AED and ELCR values ranged from 0.09 to 0.22 mSv y−1 with overall mean of 0.15 mSv y−1 and 0.33 × 10−3 to 0.77 × 10−3 with overall mean of 0.54 × 10−3, respectively. The measured dose rates were significantly higher than world average gamma radiation dose of 59 nGy h−1 for outdoor environment. The dose rates revealed an elevated background radiation levels signifying a radiation contaminated environment. The ELCR values indicate that the accumulation of low-level radiation doses over a lifetime exposure can initiate cancer development in residents of Enugu urban areas.

Assessment of radiation dose level in farm soils of mission quarters, Wukari, Taraba State, Nigerian

The study has assessed the amount of radiation exposed to farm soils in mission quarters Wukari, Taraba State. Assessment of radiation dose level is very important, especially in soil since man depends on Soil for his food. Assessment of radiation will help to know the radiation dose in the soil. The objective of this work is to determine radiation dose in soils and to provide necessary information of human health risks associated with radioactivity in soil and its effects on plant materials as well as human being. Different soil samples were collected and the Radiation Alert Inspector EXP, was used to measure the level of radiation exposure in the soil samples. The results showed low amount of radiation dose level. The average dose values ranging between 0.035±0.097 to 0.333±0.289, an absorbed dose rate ranging between 3.50 x 10-8±0.097 to 3.33 x 10-7±0.289 and annual dose rate ranging between 0.059±0.097 to 0.758±0.289. These results revealed that the dose rates do not exceed the recommended values by International Commission on Radiological Protection (ICRP) is 1mSvyr1 for the general public. It is less and in compliance with the recommended radiation dose level. Therefore do not pose a significant health hazard. The radiation dose level has no negative effect on both the plants and the dwellers. Therefore the study area is safe for human activities.

High-Dose Fluoroscopically Guided Procedures in Patients: Radiation Management Recommendations for Interventionalists.

The article is part of the series of articles on radiation protection. You can find further articles in the special section of the CVIR issue. In addition to the risks from fluoroscopic-guided interventional procedures of tissue injuries, recent studies have drawn attention to the risk of stochastic effects. Guidelines exist for preprocedural planning and radiation management during the procedure. The concept of a substantial radiation dose level (SRDL) is helpful for patient follow-up for tissue injury. The uncommon nature of tissue injuries requires the interventionalist to be responsible for follow-up of patients who receive substantial radiation doses. Dose management systems for recognizing and avoiding higher patient exposures have been introduced. The European Directive provides a legal framework and requirements for equipment, training, dose monitoring, recording and optimization that are helpful in radiation risk management.

Assessment of background ionizing radiation dose levels in quarry sites located in Ebonyi State, Nigeria

The study presents a radiometric survey of Background Ionizing Radiation (BIR) dose levels in ten quarry sites located in Ebonyi State, Nigeria. In-situ BIR dose rate measurements, by means of nuclear radiation survey meter, at 1 m above ground level were carried out at the excavation section (ES) and quarrying section (QS) of the investigated quarry sites. The obtained results indicated dose rates ranging from from 0.14 to 0.18 μSv/h with mean of 0.15±0.01 μSv/h at the ES and 0.16 to 0.19 μSv/h with mean value of 0.18±0.01 μSv/h at the QS. While the values obtained at the QS are respectively higher than those measured at the ES, they are all higher than the worldwide average value of 84 nSv/h signifying BIR elevated environments. The estimated mean annual effective dose (AED) and excess lifetime cancer risk (ELCR) are 0.27±0.03 mSv/y and 0.94×10–3 respectively at the ES and 0.31±0.02 mSv/y and 1.07×10–3 at the QS. The obtained AED values for all the sites are well above the outdoor worldwide average value of 0.07 mSv/y but lower than the International Commission on Radiological Protection recommended permissible limits of 1.0 mSv/y for the general public. Generally, the BIR levels of the quarry sites are within acceptable limits and no immediate radiological health threat may be derived from the current levels. However, long-term health effects due to continuous exposure to low-level radiation doses may manifested in future over a lifetime exposure of 70 years as indicated by the ELCR values.&#x0D; Keywords: Background ionizing radiation, Dose rate, Annual effective dose, Quarry site, Ebonyi State