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Rev. chil. radiol ; 26(1): 25-31, mar. 2020. tab
Article in Spanish | LILACS | ID: biblio-1115522


Resumen: Debido al aumento en el uso de la Tomografía Computada (TC), y en consecuencia, la probabilidad de generar un incremento progresivo de la dosis recibida por los paciente y su relación en el potencial riesgo de los efectos de las radiaciones ionizantes, es importante implementar el uso de niveles de referencia diagnóstico (DRLs) en TC, como herramienta fundamental dentro de un programa de control de calidad que permita la evaluación y optimización de las dosis entregadas a los pacientes según la tarea clínica deseada. Con el objetivo de establecer valores típicos de dosis en TC de cerebro en Clínica Bupa Reñaca, se estudió una muestra de 73 informes dosimétricos generados en un equipo TC Toshiba Aquilion 64, en términos de indicadores de dosis para TC: Índice de dosis en TC por volumen (CTDIvol) y Producto dosis longitud (DLP). Con los datos obtenidos, se estimó el valor del percentil 50 (p50) para cada indicador de dosis, y se determinaron los valores típicos de dosis en cada grupo estudiado según sexo, edad e indicación clínica. Se logró definir y establecer una metodología que permitió la obtención de los valores típicos de dosis para TC de cerebro, optimizando las dosis sin producir una disminución en la calidad de la imagen necesaria para nuestro propósito clínico.

Abstract: Due to the increase in the use of Computed Tomography (CT), and consequently, the probability of generating a progressive increase in the dose received by the patient and its relationship in the potential risk of the effects of ionizing radiation, it is important to implement the use of diagnostic reference levels (DRLs) in CT, as a fundamental tool within a quality control program that allows the evaluation and optimization of the doses delivered to patients according to the desired clinical task. In order to establish typical dose values in brain CT at Bupa Reñaca Clinic, a sample of 73 dosimetric reports generated on a Toshiba Aquilion 64 CT unit was studied, in terms of dose indicators for CT: Dose rate on CT by volume (CTDIvol) and Dose Length Product (DLP). With the data obtained, the value of the 50th percentile (p50) for each dose indicator was estimated, and typical dose values were determined in each group studied according to sex, age and clinical indication. It was possible to define and establish a methodology that allowed obtaining typical dose values for brain CT, optimizing the doses without producing a decrease in the image quality necessary for our clinical purpose.

Humans , Male , Female , Adolescent , Adult , Middle Aged , Young Adult , Radiation Dosage , Brain/diagnostic imaging , Tomography, X-Ray Computed/standards , Diagnostic Reference Levels , Quality Control , Radiation, Ionizing , Brain/radiation effects , Tomography, X-Ray Computed/methods , Cross-Sectional Studies , Process Optimization
Journal of Gorgan University of Medical Sciences. 2017; 19 (2): 38-44
in Persian | IMEMR | ID: emr-189296


Background and Objective: The electromagnetic field producer sets in daily life causes concerns about the adverse effects of such waves on human health. This study was done to evaluate the effect of cell phones microwaves on histologic structures of some visceral organs in rat

Methods: In this experimental study, 80 immature Wistar male rats with weight of 100-140 gram and 5 to 6 weeks age were randomly allocated into 3 experimental groups and one control group. The experimental rats were exposed to cell phones microwaves 5 hours a day for 1, 2 and 3 months. The control group received no radiation. After the experimental period rats were sacrificed and the appropriate tissues of the lung, heart, liver, brain and pancreas were prepared. Sections in 5 micro m thicknesses were stained by hematoxylin and eosin and studied microscopically

Results: Histological changes including edema, inflammatory cell infiltration and cell degeneration in the lung and mild degeneration and coagulation necrosis of the myocardial cells in the heart were observed. Histopthological examination of the liver revealed dilation of central veins and sinusoids, vacuolization of hepatocytes and mononuclear inflammatory cell infiltration. Limited changes were observed in pancreas and brain. Histological changes were increased in the groups that were exposed longer period of time to radiation

Conclusion: This study indicated that the harmful effect of cell phones radiation on rat tissues depending on the duration of exposure

Animals, Laboratory , Cell Phone , Viscera/radiation effects , Lung/radiation effects , Heart/radiation effects , Liver/radiation effects , Brain/radiation effects , Pancreas/radiation effects , Rats, Wistar
Article in English | WPRIM | ID: wpr-66007


Emerging concerns regarding the hazard from medical radiation including CT examinations has been suggested. The purpose of this study was to observe the longitudinal changes of CT radiation doses of various CT protocols and to estimate the long-term efforts of supervising radiologists to reduce medical radiation. Radiation dose data from 11 representative CT protocols were collected from 12 hospitals. Attending radiologists had collected CT radiation dose data in two time points, 2007 and 2010. They collected the volume CT dose index (CTDIvol) of each phase, number of phases, dose length product (DLP) of each phase, and types of scanned CT machines. From the collected data, total DLP and effective dose (ED) were calculated. CTDIvol, total DLP, and ED of 2007 and 2010 were compared according to CT protocols, CT machine type, and hospital. During the three years, CTDIvol had significantly decreased, except for dynamic CT of the liver. Total DLP and ED were significantly decreased in all 11 protocols. The decrement was more evident in newer CT scanners. However, there was substantial variability of changes of ED during the three years according to hospitals. Although there was variability according to protocols, machines, and hospital, CT radiation doses were decreased during the 3 years. This study showed the effects of decreased CT radiation dose by efforts of radiologists and medical society.

Abdomen/radiation effects , Angiography , Brain/radiation effects , Female , Hospitals , Humans , Liver/radiation effects , Longitudinal Studies , Male , Middle Aged , Radiation Dosage , Tomography, X-Ray Computed/instrumentation
Braz. j. med. biol. res ; 48(10): 915-922, Oct. 2015. ilus
Article in English | LILACS | ID: lil-761596


Understanding the effects of radiation and its possible influence on the nervous system are of great clinical interest. However, there have been few electrophysiological studies on brain activity after exposure to ionizing radiation (IR). A new methodological approach regarding the assessment of the possible effects of IR on brain activity is the use of linear and nonlinear mathematical methods in the analysis of complex time series, such as brain oscillations measured using the electrocorticogram (ECoG). The objective of this study was to use linear and nonlinear mathematical methods as biomarkers of gamma radiation regarding cortical electrical activity. Adult Wistar rats were divided into 3 groups: 1 control and 2 irradiated groups, evaluated at 24 h (IR24) and 90 days (IR90) after exposure to 18 Gy of gamma radiation from a cobalt-60 radiotherapy source. The ECoG was analyzed using power spectrum methods for the calculation of the power of delta, theta, alpha and beta rhythms and by means of the α-exponent of the detrended fluctuation analysis (DFA). Using both mathematical methods it was possible to identify changes in the ECoG, and to identify significant changes in the pattern of the recording at 24 h after irradiation. Some of these changes were persistent at 90 days after exposure to IR. In particular, the theta wave using the two methods showed higher sensitivity than other waves, suggesting that it is a possible biomarker of exposure to IR.

Animals , Male , Cerebral Cortex/radiation effects , Electrocorticography/methods , Gamma Rays/adverse effects , Radiation, Ionizing , Radiation Injuries/diagnosis , Biomarkers , Brain/radiation effects , Linear Models , Nonlinear Dynamics , Rats, Wistar , Statistics, Nonparametric , Time
Indian J Biochem Biophys ; 2014 Apr; 51(2): 135-141
Article in English | IMSEAR | ID: sea-154251


Ionizing radiation is known to induce multiple organ dysfunctions directly related to an increase of cellular oxidative stress, due to overproduction of reactive oxygen species (ROS). This study was aimed to investigate the effect of septilin (an ayurvedic poly-herbal formulation containing the principal herbs, namely Commiphora wightii, Trinospora cordifolia, Rubia cardifolia, Emblica officinalis, Saussurea lappa and Glycyrrhiza glabra) against whole body γ-irradiation-induced oxidative damage in hepatic and brain tissues in rats. Administration of septilin for 5 days (100 mg/kg) prior to radiation resulted in a significant increase in both superoxide dismutase (SOD) activity and total glutathione (GSH) level in hepatic and brain tissues, while serum high-density lipoprotein-cholesterol (HDL) was reduced by γ-irradiation. Also, septilin resulted in a significant decrease in NO(x), nitric oxide and malondialdehyde (MDA) levels in hepatic and brain tissues and a significant decrease in serum triglycerides, low-density lipoprotein-cholesterol (LDL) and total cholesterol levels and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels and alkaline phosphatase (ALP), γ-glutamyl transferase (GGT) activities, as well as serum tumor necrosis factor-alpha (TNF-α), compared to irradiated group. In conclusion, data obtained from this study indicated that septilin exhibited potential antioxidant activity and showed radioprotective effect against γ-radiation by preventing oxidative stress and scavenging free radicals.

Alanine Transaminase/metabolism , Animals , Antioxidants/pharmacology , Aspartate Aminotransferases/metabolism , Brain/drug effects , Brain/metabolism , Brain/radiation effects , Gamma Rays/adverse effects , Glutathione/metabolism , Liver/drug effects , Liver/metabolism , Liver/radiation effects , Male , Oxidative Stress/drug effects , Oxidative Stress/radiation effects , Plant Extracts/pharmacology , Radiation-Protective Agents/pharmacology , Rats , Rats, Sprague-Dawley , gamma-Glutamyltransferase
Saudi Medical Journal. 2014; 35 (11): 1393-1395
in English | IMEMR | ID: emr-153968


Toxic epidermal necrolysis [TEN] is a severe drug induced type IV hypersensitivity syndrome that can be caused by anticonvulsant drugs, especially the aromatic anticonvulsants such as phenytoin. Most patients with brain metastasis receive whole brain radiotherapy along with anti-edema measures and anticonvulsants either as prophylactic or for symptom control; phenytoin being the most commonly used drug. In a subset of patients, cranial irradiation may act as a precipitating factor along with anticonvulsants for the development of TEN. We report a 54-year-old patient with metastatic non-small cell lung cancer treated with palliative whole brain and mediastinal radiotherapy with concurrent phenytoin-developing TEN, which started within the radiation portals with subsequent generalization. Though a rare, but serious complication, avoidance of the use of phenytoin concurrent with radiotherapy, replacing phenytoin with newer anticonvulsants, early recognition, aggressive management and awareness of this possible complication has been implied upon in this report

Humans , Male , Stevens-Johnson Syndrome/diagnosis , Phenytoin/toxicity , Brain/radiation effects , Thorax/radiation effects , Radiotherapy/adverse effects
Indian J Exp Biol ; 2013 Dec; 51(12): 1079-1085
Article in English | IMSEAR | ID: sea-150295


A specific absorption rate (SAR) measurements system has been developed for compliance testing of personal mobile phone in a brain phantom material contained in a Perspex box. The volume of the box has been chosen corresponding to the volume of a small rat and illuminated by a 3G mobile phone frequency (1718.5 MHz), and the emitted radiation directed toward brain phantom .The induced fields in the phantom material are measured. Set up to lift the plane carrying the mobile phone is run by a pulley whose motion is controlled by a stepper motor. The platform is made to move at a pre-determined rate of 2o per min limited up to 20o. The measured data for induced fields in various locations are used to compute corresponding SAR values and inter comparison obtained. These data are also compared with those when the mobile phone is placed horizontally with respect to the position of the animal. The SAR data is also experimentally obtained by measuring a rise in temperature due to this mobile exposures and data compared with those obtained in the previous set. To seek a comparison with the safety criteria same set of measurements are performed in 10 g phantom material contained in a cubical box. These results are higher than those obtained with the knowledge of induced field measurements. It is concluded that SAR values are sensitive to the angular position of the moving platform and are well below the safety criteria prescribed for human exposure. The data are suggestive of having a fresh look to understand the mode of electromagnetic field -bio interaction.

Absorption , Animals , Brain/radiation effects , Cell Phone , Electromagnetic Fields , Humans , Phantoms, Imaging , Radiometry , Rats
Indian J Exp Biol ; 2013 Mar; 51(3): 187-200
Article in English | IMSEAR | ID: sea-147582


Wireless technologies are ubiquitous today and the mobile phones are one of the prodigious output of this technology. Although the familiarization and dependency of mobile phones is growing at an alarming pace, the biological effects due to the exposure of radiations have become a subject of intense debate. The present evidence on mobile phone radiation exposure is based on scientific research and public policy initiative to give an overview of what is known of biological effects that occur at radiofrequency (RF)/ electromagnetic fields (EMFs) exposure. The conflict in conclusions is mainly because of difficulty in controlling the affecting parameters. Biological effects are dependent not only on the distance and size of the object (with respect to the object) but also on the environmental parameters. Health endpoints reported to be associated with RF include childhood leukemia, brain tumors, genotoxic effects, neurological effects and neurodegenerative diseases, immune system deregulation, allergic and inflammatory responses, infertility and some cardiovascular effects. Most of the reports conclude a reasonable suspicion of mobile phone risk that exists based on clear evidence of bio-effects which with prolonged exposures may reasonably be presumed to result in health impacts. The present study summarizes the public issue based on mobile phone radiation exposure and their biological effects. This review concludes that the regular and long term use of microwave devices (mobile phone, microwave oven) at domestic level can have negative impact upon biological system especially on brain. It also suggests that increased reactive oxygen species (ROS) play an important role by enhancing the effect of microwave radiations which may cause neurodegenerative diseases.

Animals , Apoptosis , Biophysics/methods , Brain/radiation effects , Brain Neoplasms/etiology , Cell Cycle , Cell Line, Tumor , Cell Phone , Central Nervous System/radiation effects , DNA Damage/radiation effects , Electromagnetic Fields , Environmental Exposure , Free Radicals , Humans , Mice , Models, Biological , Mutagens , Neoplasms, Radiation-Induced/diagnosis , Radiometry , Rats , Reactive Oxygen Species
KOOMESH-Journal of Semnan University of Medical Sciences. 2011; 12 (2): 167-174
in Persian | IMEMR | ID: emr-125113


Effects of extremely low frequency magnetic fields [ELF-MF] with different intensities and frequencies has been investigated by several researchers. In most of these studies, the applied magnetic field has uniformly encountered whole brain and it has shown that changing intensity and frequency causes anomaly changes in electroencephalograms. The aim of current study was to investigate the effect of local exposure to ELF-MF with different intensities on EEG signals. Magnetic field with frequency of 10 Hz and intensity of 100, 120, 160, 200, 240, 280, 320 and 360 micro T was applied to F3 zone in 10-20 system of 3 men locally. Finally, relative power spectrum in 5 points of head in conventional frequency bands was assessed. An increase in alpha band in regions under exposure such as F3 and O1 in intensities of 100 and 360 micro T was observed. No changes in other bands such as theta band were found. It should be noted that none of the above effects was observed in closed-eye position. Regular effects due to increasing intensity of magnetic field was not observed and changing potential of EEG signals from magnetic field with intensity of 100 and 360 micro T is more than other intensities. Changing pattern of alpha band in F4, Cz, O2 and O1 was similar to exposed F3 zone and no resonance effect was observed at 10 Hz magnetic field

Brain/radiation effects , Dose-Response Relationship, Radiation , Radiation Dosage , Electroencephalography
Medical Journal of Cairo University [The]. 2008; 76 (3 Supp. I): 105-108
in English | IMEMR | ID: emr-101441


Increasing use of mobile phones [MPs] by the growing vulnerable children in Egypt arouses the question about their effect on the electrical activity of the brain. To detect the early effects of MP use on the electrical activity of the brain in children. Study population: School-aged children of both sexes attending El-Sahel Teaching Hospital for mild illness. Thirty-three MP users and 40 non-users were given appointments after recovery to be recruited in the study. A questionnaire including psychiatric symptoms was filled followed by eliciting electroencephalography [EEG] after 5 minutes of MP use. The frequency of the psychiatric symptoms and EEG changes were significantly higher in the MP users than in non-users [p<0.05 and 0.01 respectively]. There is an increase in estimated risk [Odds ratio] of developing psychiatric symptoms and EEG changes in the MP users [3.9 and 5.8 respectively]. There was a significant increase in the frequency of the generalized paroxysmal waves in EEG among the MP users than non-users [33.3% Vs. 12.5% respectively] [p<0.01]. The effect of MP use on presence of psychiatric symptoms and on EEG in this study alarms the restriction of MP use by children

Humans , Male , Female , Radiation Injuries , Brain Mapping , Child , Schools , Electroencephalography , Surveys and Questionnaires , Psychological Tests , Brain/radiation effects
Ain-Shams Journal of Forensic Medicine and Clinical Toxicology. 2005; 4: 46-59
in English | IMEMR | ID: emr-69282


Cellular telephones are low-power radio devices that transmit and receive electromagnetic radiation at frequencies ranging between 900 megahertz and 1800 gigahertz. The aim of the present study was to investigate the adverse effects of long-term exposure to low level radio frequency electromagnetic signals currently used in digital mobile telecommunications on albino rats' brain. Ninety male albino rats were included in the current study which were further subdivided into four groups [negative control, sham exposed, 30 minutes period exposed and 60 minutes period exposed].The rats were exposed daily for 3 months to mobile phone electromagnetic signals of 900 megahertz for different time durations. At the end of the study, sixty animals were sacrificed while the rest animals were left unexposed to any electromagnetic signals for further 30 days then sacrificed later on. Brains from all sacrificed animals were fixed and immunohistochemically stained using albumin antibody. Serial sections from fixed tissues were also stained for RNA/ DNA with cresyl violet. The results had shown significant evidences for breakdown in blood brain barrier, positive albumin leakage and neuronal damage. Neuronal damage was recorded in the cortex, hippocampus and the basal ganglia as well. The neuronal albumin leakage and other detected changes would seem to indicate a serious neuronal damage. The study showed that long term exposure to EMF signals was found to destroy cells in parts of the rats' brain important for memory, movement and learning which could possibly cause premature onset of illnesses such as Alzheimers. Furthermore, the resultant changes were still persistent in rats left untreated for one additional month. In conclusion, these findings suggest that frequent exposure to mobile phone signals might carry a risk for chronic users. It is worthy to advice for minimizing the mobile phone use as much as possible

Animals, Laboratory , Telephone , Electromagnetic Fields/adverse effects , Rats , Animals, Laboratory , Brain/pathology , Immunohistochemistry , Brain/radiation effects
Egyptian Journal of Biophysics and Biomedical Engineering. 2002; 3: 113-129
in English | IMEMR | ID: emr-59185


In this work, four groups of adult male albino rats were used; the first as control, the second was exposed to microwave radiation 11/2 hr/day for seven consecutive days at a dose of 15 mW/cm2 and frequency 10.525 CHz. The third was exposed like the second but for 24 consecutive days, while the fourth was treated as the third and then left for two weeks as a rest period. Then animals were sacrificed and the blood and brain levels of some major and trace elements [calcium. iron, manganese, copper, nickel, zinc, selenium and molybdenum] were estimated by the Energy Dispersive X-ray Fluorescence technique [EDXF]; an easy, rapid, multi-elemental and need low weight of samples. Calcium, iron and manganese showed a significant increase in the exposed groups, while zinc, copper and molybdenum showed a significant decrease in both blood and brain when compared to control. Nickel of blood exposed groups showed a significant drop in the acute and chronic exposure groups and restored its normal figure in the chronic exposure then rest group, but it gave no readings in the brain sample for all groups. As for selenium it showed a significant drop in both acute and chronic exposure groups and a significant rise in the chronic then rest group in the blood; but in brain it gave no readings for the control and chronic exposure groups and a significant rise in the other two. These changes were explained by the microwave variant effects on ion fluxes via the effect on the ion channel properties of cell membrane, interaction between the cellular membrane molecules containing these ions, voltage changes across the cell membrane. etc

Animals, Laboratory , Calcium/blood , Iron/blood , Manganese/blood , Copper/blood , Nickel/blood , Zinc/blood , Selenium/blood , Brain/radiation effects , Spectrometry, X-Ray Emission , Rats , Blood/radiation effects , Animals, Laboratory
Article in English | WPRIM | ID: wpr-197881


Total excision is a treatment of choice in preventing the relapse of craniopharyn-gioma, but for tumors involving an extensive area, it is often associated with an increased risk of complications. We have performed a partial or subtotal tumor removal followed by repeated injection of bleomycin into the remaining tumor through a subcutaneous reservoir as postoperative adjuvant therapy. A retro-spective review of clinical, radiological, and surgical data was performed for 10 patients (5 males and 5 females; age, 3-65 yr; follow-up duration, 12-79 months) with cystic craniopharyngiomas. The measurements of lactate dehydrogenase (LDH) level at each aspiration were performed. The shrinkage and/or stabiliza-tion of tumor was initially noted in all cases. The recurrence of tumor was seen in 4 cases (40%). The decreased or increased level of LDH was interpreted as tumor shrinkage or recurrence, respectively. The transient toxic reactions were observed in 3 patients (30%). Our study demonstrates that postoperative bleo-mycin injection for cystic craniopharyngioma, although does not appear to eradi-cate the tumor, decreases and stabilizes the tumor size, when used as an adju-vant therapy in young patients.

Adolescent , Adult , Aged , Antibiotics, Antineoplastic/administration & dosage , Bleomycin/administration & dosage , Brain/radiation effects , Child , Child, Preschool , Craniopharyngioma/drug therapy , Female , Follow-Up Studies , Humans , Injections , L-Lactate Dehydrogenase/metabolism , Male , Middle Aged , Pituitary Neoplasms/drug therapy , Postoperative Care , Retrospective Studies , Tomography, X-Ray Computed/methods