Practical guidance on the assessment of radiation risks for diagnostic radiological examinations.

Patient doses cannot be limited; instead, radiological examinations should be justified and optimised to ensure the necessary diagnostic or therapeutic effect with the lowest patient dose achievable. Assessment of the radiation risks from patient exposure is important part of the justification process. Hence, medical staff within the framework of their professional activities should possess necessary information on the data on radiation risk from different types of radiological procedures.

Air kerma rate from radionuclides distributed in forest ecosystem.

This study evaluates the air kerma rate in radioactively contaminated forests. The air kerma rates created by plane sources of monoenergetic photons in the energy range 0.02-3 MeV located at different depths in soil up to 50 g cm and at different heights in the forest medium from 0.

COMPARISON OF ORGAN ABSORBED DOSES IN WHOLE-BODY COMPUTED TOMOGRAPHY SCANS OF PAEDIATRIC AND ADULT PATIENT MODELS ESTIMATED BY DIFFERENT METHODS.

This study aimed to identify the uncertainty in estimations of organ absorbed dose using dedicated software by comparing with corresponding doses measured in physical phantoms. The comparison was performed for whole-body computed tomography (CT) obtained as part of positron emission tomography. Whole-body CT scans provide an advantage in terms of comparison because all organs are in the primary beam of the irradiated area.

ESTIMATION OF THE EFFECTIVE DOSES FROM TYPICAL FLUOROSCOPIC EXAMINATIONS WITH BARIUM CONTRAST.

The current study aimed to estimate the effective doses and conversion coefficients (CCs) for typical barium swallow (BS), barium meal (BM) and barium enema (BE) protocols and to evaluate the impact of different examination parameters on the resulting CCs. Data were collected in surgical and therapy departments in St. Petersburg Urban Mariinsky Hospital.

Technical Note: Patient-weight dependence of the effective dose conversion coefficients for diagnostic x-ray imaging procedures.

Purpose: The aim of this study was to provide a method and reference data for the evaluation of the weight dependence of the conversion coefficients from air collision kerma integrated over beam area to the effective dose for patients undergoing diagnostic x-ray examinations.

Method: A simple physics-based analytical model was developed in order to calculate the weight dependence of the effective dose conversion coefficients based on existing values of the conversion coefficients between patient effective dose and air collision kerma integrated over beam area calculated by the Monte Carlo method on the base of computational MIRD-5-type stylized models.

Results: The analytical expressions that make possible taking into account a patient's weight when assessing the effective dose were presented.

ASSESSMENT OF THE ABSORBED DOSES IN THE ORGANS IN CASE OF RADIATION EMERGENCY WITH THE SEALED GAMMA-SOURCES.

The majority of the radiation accidents with early acute clinical effects were associated with the orphan sources used in industrial and medical facilities. These accidents involved members of general public, who were entirely unaware of the exposure to the radiation. In such situations, the exposure commonly occurs when the source is in contact with a body of a victim, primarily located in pockets of clothing or in hands.

Patient doses from medical examinations in Russia: 2009-2015.

The aim of this study was to evaluate adult patient doses in Russia in the context of patient protection. Effective doses from x-ray and nuclear medicine examinations were assessed using two approaches. The first was based on data collection performed by the authors in hospitals in St.

A COMPARATIVE STUDY OF ORGAN DOSES ASSESSMENT FOR PATIENTS UNDERGOING CONVENTIONAL X-RAY EXAMINATIONS: PHANTOM EXPERIMENTS VS. CALCULATIONS.

A series of phantom experiments were performed with the aim of estimating organ doses for patients undergoing conventional X-ray chest and pelvis examinations. The experiments were performed using physical phantoms corresponding to an adult and a 5-year-old child. Mean organ doses and entrance surface dose were measured using TL-dosemeters.

PROPOSALS FOR THE ESTABLISHMENT OF NATIONAL DIAGNOSTIC REFERENCE LEVELS FOR RADIOGRAPHY FOR ADULT PATIENTS BASED ON REGIONAL DOSE SURVEYS IN RUSSIAN FEDERATION.

In 2009-2014, dose surveys aimed to collect adult patient data and parameters of most common radiographic examinations were performed in six Russian regions. Typical patient doses were estimated for the selected examinations both in entrance surface dose and in effective dose. 75%-percentiles of typical patient effective dose distributions were proposed as preliminary regional diagnostic reference levels (DRLs) for radiography.

Russian practical guidance on radiological support for justification of X-ray and nuclear medicine examinations.

An important part of the justification process is assessment of the radiation risks caused by exposure of a patient during examination. The authors developed official national methodology both for medical doctors and sanitary inspectors called 'assessment of radiation risks of patients undergoing diagnostic examinations with the use of ionizing radiation'. The document addresses patients of various age groups and a wide spectrum of modern X-ray and nuclear medicine examinations.

Paediatric doses in St Petersburg hospitals.

The exposure of paediatric patients during X-ray examinations in St Petersburg hospitals was investigated. Data about radiography examinations were collected, and mean patient effective doses and entrance surface air kerma for each X-ray unit were estimated. The results of the study were compared with other countries practice.

Wavelet transform fuzzy algorithms for dermoscopic image segmentation.

This paper presents a novel approach to segmentation of dermoscopic images based on wavelet transform where the approximation coefficients have been shown to be efficient in segmentation. The three novel frameworks proposed in this paper, W-FCM, W-CPSFCM, and WK-Means, have been employed in segmentation using ROC curve analysis to demonstrate sufficiently good results. The novel W-CPSFCM algorithm permits the detection of a number of clusters in automatic mode without the intervention of a specialist.

Reflection of nanosecond Nd:YAG laser pulses in ablation of metals.

Hemispherical total reflectivity of copper, nickel, and tungsten in ablation by nanosecond Nd:YAG laser pulses in air of atmospheric pressure is experimentally studied as a function of laser fluence in the range of 0.1-100 J/cm(2). Our experiment shows that at laser fluences below the plasma formation threshold the reflectivity of mechanically polished metals remains virtually equal to the table room-temperature reflectivity values.

Release criteria for patients having undergone radionuclide therapy and criteria for their crossing the state border of the Russian Federation.

By means of a conservative dosimetry model, the values of operational radiological criteria for patients released from hospital--residual activity in a body and dose rate near the patient's body--are substantiated based on the effective dose limit of 5 mSv for persons helping the patient or living with him and 1 mSv for other adults and children. Two sets of operative criteria for radionuclides (125)I, (131)I, (153)Sm and (188)Re used in Russia for radionuclide therapy were derived. Release criteria for (125)I well differ from such values in other countries because in this work absorption of (125)I low-energy photon radiation in the patient was taken into account.

[The characteristics of anaesthesiologic service in territories with low density of population settlement].

The data of the study of sociological and expertise survey of physicians of surgery profile and anaesthesiologists-reanimators is presented. The Delphi technique was applied to determine the qualitative degree of interrelationship of elements? Characteristics in the functioning of the anaesthesiologic service. These studies are topical because of serious issues of anaesthesiologic service in the territories with lower density of population settlement to be resolved through the enhancement of its overall functioning.

Studies of patient doses in interventional radiological examinations.

In Russia, especially in big cities like St. Petersburg, the annual number of interventional radiological (IR) examinations for both diagnostic and treatment purposes is increasing continuously. However, IR examinations might involve high patient doses and even the risk of skin injures that should be prevented.

Radioecological studies at the Kraton-3 underground nuclear explosion site in 1978-2007: a review.

Within this paper, radioecological data concerning the "peaceful" underground nuclear explosion Kraton-3, conducted at a remote Arctic location (65.9 degrees N, 112.3 degrees E) within the former USSR in 1978, are reviewed.

Modelling of a large-scale urban contamination situation and remediation alternatives.

The Urban Remediation Working Group of the International Atomic Energy Agency's EMRAS (Environmental Modelling for Radiation Safety) program was organized to address issues of remediation assessment modelling for urban areas contaminated with dispersed radionuclides. The present paper describes the first of two modelling exercises, which was based on Chernobyl fallout data in the town of Pripyat, Ukraine. Modelling endpoints for the exercise included radionuclide concentrations and external dose rates at specified locations, contributions to the dose rates from individual surfaces and radionuclides, and annual and cumulative external doses to specified reference individuals.

Improvement of modelling capabilities for assessing urban contamination: the EMRAS Urban Remediation Working Group.

The Urban Remediation Working Group of the International Atomic Energy Agency's Environmental Modelling for Radiation Safety (EMRAS) programme was established to improve modelling and assessment capabilities for radioactively contaminated urban situations, including the effects of countermeasures. An example of the Working Group's activities is an exercise based on Chernobyl fallout data in Ukraine, which has provided an opportunity to compare predictions among several models and with available measurements, to discuss reasons for discrepancies, and to identify areas where additional information would be helpful.

Inter-comparison of absorbed dose rates for non-human biota.

A number of approaches have been proposed to estimate the exposure of non-human biota to ionizing radiation. This paper reports an inter-comparison of the unweighted absorbed dose rates for the whole organism (compared as dose conversion coefficients, or DCCs) for both internal and external exposure, estimated by 11 of these approaches for selected organisms from the Reference Animals and Plants geometries as proposed by the International Commission on Radiological Protection. Inter-comparison results indicate that DCCs for internal exposure compare well between the different approaches, whereas variation is greater for external exposure DCCs.

Evaluation of conversion coefficients from measurable to risk quantities for external exposure over contaminated soil by use of physical human phantoms.

Conversion coefficients from measurable quantities such as air kerma free-in-air or personal dose equivalent to effective dose were determined by phantom experiments. Heterogenic anthropomorphic phantoms representing children of one and five years age, and a Rando phantom representing an adult were exposed in the open field contaminated by different levels of radiocesium in the upper soil layer, in a forest site and inside a wooden house. LiF thermoluminescent (TL) detectors were used inside the phantoms for the estimation of organ doses and effective dose.

Assessment of current exposure of the population living in the Techa River basin from radioactive releases of the Mayak facility.

Current doses arising from external and internal pathways have been estimated for the residents of two villages, Muslumovo and Brodokalmak, alongside the Techa River, which was contaminated by radioactive releases from the Mayak production facility. The dose estimates are based on numerous environmental measurements supplemented by further human whole body measurements and studies on occupational and dietary habits of Slavic and Turkish ethnic groups. Estimated doses arise mainly from use of the contaminated floodplains alongside the Techa River.

Surface ground contamination and soil vertical distribution of 137Cs around two underground nuclear explosion sites in the Asian Arctic, Russia.

Vertical distributions of 137Cs have been determined in vegetation-soil cores obtained from 30 different locations around two underground nuclear explosion sites--"Crystal" (event year - 1974) and "Kraton-3" (event year - 1978) in the Republic of Sakha (Yakutia), Russia. In 2001-2002, background levels of 137Cs surface contamination densities on control forest plots varied from 0.73 to 0.

Modelling of long-term behaviour of caesium and strontium radionuclides in the Arctic environment and human exposure.

In this paper a compartment model of the highly vulnerable Arctic terrestrial food chain "lichen-reindeer-man" is outlined. Based upon an analysis of measured (137)Cs and (90)Sr contents in lichen and reindeer meat from 1961 up to 2001, site specific model parameters for two regions in north-western Arctic Russia and for Kautokeino municipality in Arctic Norway have been determined. The dynamics of radionuclide activity concentrations in the "lichen-reindeer-man" food chain for all areas was satisfactorily described by a double exponential function with short-term and long-term effective ecological half-lives between 1-2 and 10-12 years, respectively, for both (137)Cs and (90)Sr.

Comparison of retrospective luminescence dosimetry with computational modeling in two highly contaminated settlements downwind of the Chernobyl NPP.

The cumulative absorbed dose in bricks collected from six buildings in two heavily contaminated settlements (137Cs > 2,000 kBq m(-2)) located downwind of the Chernobyl Nuclear Power Plant was determined using luminescence techniques by six laboratories. The settlements, Vesnianoje in Ukraine and Zaborie in Russia, are located in, respectively, proximal and distal locations relative to the Chernobyl Nuclear Power Plant. The luminescence determinations of cumulative dose in brick, after subtraction of the natural background dose, were translated to absorbed dose in air at a Reference Location using conversion factors derived from Monte Carlo simulations of photon transport.