ABSTRACT Afforestation of sites disturbed after bauxite mining is the favorite technique to restore all ecosystem functions. The nature of the tree species used for revegetation of post-mining land can accelerate the recovery of soil organic matter and nutrient cycles. This study aimed to determine the litterfall production, decomposition rate and nutrient content from three types of forest cover ( Eucalyptus , Anadenanthera peregrina , mixed plantation of 16 native species) planted in a bauxite mining area in recovery. Litterfall production was evaluated monthly over 30 months, and the litter mass was assessed twice a year (dry and rainy periods). Total nutrient content was determined from samples grouped by period (dry and rainy). The annual average values for litterfall dry mass and litter mass were higher in Eucalyptus and mixed native. The period (dry or rainy) did not influence litterfall rates in A. peregrina , but Eucalyptus and mixed native presented higher amounts for litterfall during the rainy and dry periods, respectively. Litter accumulation in Eucalyptus was not affected by the season of the year, but mixed native and A. peregrina presented higher litter accumulation in the dry season. Apparent decomposition rates of A. peregrina and mixed native were higher in the rainy season, highlighting the A. peregrina with the highest values compared with the other forest covers. The mixed native presented the highest leaf content of P, K, Ca and Mg in both the litterfall and litter mass, while Eucalyptus had the lowest P, K, Ca, S and N content and the highest C content in the litterfall. Litterfall production is important in degraded areas to ensure the nutrient return to the soil. The data obtained suggest that the cultivation of a mixed of 16 native trees contribute for produce the higher annual litterfall yields, besides produces leaf litterfall of better nutritional quality in relation to P, K, Ca, Mg and S. Therefore, mixed of native trees can be a promising option for reactivation of nutrient cycling and organic matter formation in mined area of bauxite in the Brazilian Atlantic Forest.

ABSTRACT Mining is a significant driver of soil mobilization, which impacts its physical, chemical, and biological properties. Changes in land-use affect the distribution of organic matter fractions in stable aggregates, a process that is still poorly understood, especially in drastically altered areas. Recovering and monitoring soil quality to ensure the sustainable development of agricultural crops in these areas after mining is challenging. This study aimed to evaluate the influence of agronomic practices in soil rehabilitation in a bauxite-mined area after three years of field experiment installations through an assessment of organic properties in soil and aggregate classes; an attempt was also made at proposing and elaborating a Soil Quality Index (SQI), which encompasses the soil’s physical, chemical, and organic properties. Different combinations of fertilization treatments and ground cover plants intercropping with coffee were evaluated as rehabilitation practices. The results showed that after three years of rehabilitation, when organic (OF), chemical (CF), and OF+CF fertilizers were applied to the areas of coffee intercropped with Brachiaria (B), they provided higher C and N contents to the soil and aggregates classes, as well as the compartments of soil organic matter (SOM). The minimum set of soil quality indicators for reclaimed bauxite-mined areas was composed of organic indicators: labile organic carbon (LOC) and mineral-associated organic matter (C-MOM); chemical indicators including pH and effective cation-exchange capacity (t), and physical indicators such as the bulk density (BD) and stable aggregates index in water (SAIW). The t and pH were the variables most sensitive to the management systems implanted during the rehabilitation of the mined area, and, therefore, were considered the best indicators of soil quality. Brachiaria was the cover plant that contributed most to improving the soil quality of mined bauxite areas by increasing the SQI, especially when fertilized. In general, when applied to the Brachiaria, the OF+CF fertilization presented a SQI of 0.78, differing statistically from that of the natural vegetation (1.00). Fertilizers and cover crops in association with coffee in the bauxite-mined areas improved the physical, chemical, and organic properties of the soil, thus representing a viable option for reconditioning mineral exploration areas.

ABSTRACT The long-term use of agrichemicals might add some heavy metals to soils and, there is little information about the dynamics of these elements in soils under saline conditions in semiarid regions. This study aimed to investigate the dynamics of heavy metals in the different fractions of Fluvic Entisols with saline conditions under long term of coconut cultivation in a semiarid region. Composite soil samples were collected in five agricultural areas and three areas under native vegetation. Physical, chemical, and heavy metal analyses were carried out in soil (semi total and fractionated contents). Quality of irrigation water and drainage water was also evaluated. Analytical results were normalized and subjected to analysis of variance, and means were compared by Scott-Knott test (P < 0.05). Pearson correlation analysis was also used to assure a minimum correlation of variables justifying its use in the matrix of a factorial analysis. Semi-total contents of Cr, Ni, Pb and Zn (except Cu in some areas) were lower than previous local assessment and national guiding values, indicating that they do not cause harmful alterations in soil quality. Analyses of waters showed high levels of HCO3, indicating moderate restriction to use (due to the high levels of EC, SAR, Na and Cl). Fractionation of heavy metals revealed low risk of environmental pollution since most metal contents were bound to the oxidic, organic and residual fractions. The water used in irrigation contributes to the contents of heavy metals and to the salinity condition of the evaluated soils.

ABSTRACT Compaction caused by mechanization affects soil quality and, consequently, the development of crops. This study aimed to evaluate the effect of different degrees of soil compaction on the physiology, morphology, and anatomy of different coffee cultivars in a controlled environment. The experiment was carried out in a greenhouse, with randomized block design in a 5 × 5 factorial arrangement, with five coffee cultivars (Arara, Catuaí Amarelo IAC 62, Catuaí Vermelho 144, MGS Paraíso 2 and Mundo Novo IAC 379-19) and five degrees of compaction (68, 74, 80, 86 and 92 %), with four repetitions, totaling 100 experimental units. The following variables were evaluated in the aboveground biomass: plant height, number of leaves, diameter of the orthotropic branch, fresh mass of leaves and stem, leaf area, gas exchange, and chlorophyll a and b index; in the roots: length, surface area, volume, diameter of fine and coarse roots, fresh and dry mass of roots, as well as anatomical characteristics. Results showed that soil with degrees of compaction above 80 % negatively affected the variables evaluated. Catuaí Vermelho 144 presented the worst performance regardless of the degree of compaction, while Arara and MGS Paraíso 2 showed the best performance under the evaluated compaction degrees. Anatomical structure of the roots was modified with soil compaction, and no differences were observed among cultivars.

Abstract The behavior and feeding habits of different species of seabirds can influence the enrichment of trace metals in Antarctic soils. This study aimed to evaluate the influence of different species of seabirds on the concentrations of potentially toxic metals in Antarctic soils. For this, we collected soil samples in areas influenced by penguins, kelp gulls, and giant petrels. We analyzed the concentration of total organic carbon (TOC), total nitrogen (TN), available phosphorus (P) and metals by three different methods of extraction: USEPA 3051A, Mehlich-1, and distilled water. The concentrations of Cr and Hg presented positive correlations with P, TOC, and TN by the USEPA 3051A method, indicating the biotransport of these metals by seabirds. Soils influenced by penguins showed higher levels of P, TOC, TN, Cr, and Hg. Comparing the results from the different extractors, we found that Hg had the highest relative levels in the exchangeable fraction and the soil solution. Therefore, the soils with the influence of penguins present higher levels of biotransported trace metals, but this does not necessarily mean that these birds have a higher biotransport potential, since the concentration of trace metals in these soils may be related to their degree of ornithogenesis.

RESUMO Considerando a importância do Silício (Si) para as plantas, nas últimas décadas muitos estudos avaliaram a capacidade do elemento em aliviar o estresse abiótico em diferentes espécies, a maioria delas de interesse agrícola. Para todas as espécies, o Si oferece uma gama de benefícios às plantas na redução dos efeitos do estresse biótico e abiótico, estando especialmente associado a aumentos na biomassa das plantas. No entanto, quando realizamos uma revisão quantitativa sistemática de estudos que relacionam o Si ao alívio do estresse abiótico em plantas, demonstramos que há uma redução dos efeitos do Si ao longo do tempo e que os efeitos do silício foram menores nos estudos mais recentes. Além disso, descobrimos que plantas sob diferentes tipos de estresse tiveram respostas semelhantes ao Si, sugerindo que os mecanismos de alívio do estresse abiótico nas plantas podem ser comuns entre as condições de estresse hídrico, salinidade e metais pesados – os principais estresses ambientais estudados na literatura. Nosso estudo pode direcionar estudos futuros, que não devem se limitar a simplesmente avaliar a existência de quaisquer efeitos de alívio de estresse do Si, mas também compreender a variação que existe nesses mecanismos e que depende do tipo de estresse e dos fatores envolvidos na redução desses efeitos.

ABSTRACT Considering the importance of Silicon (Si) for plants, many studies have focused to evaluate the ability of the element to alleviate abiotic stress in different species, mainly of agricultural interest. For all species, Si offers a range of benefits in reducing the effects of biotic and abiotic stress, being especially associated with increases in plant biomass. However, after performed a systematic quantitative review of studies linking Si to the relief of abiotic stress in plants, it was demonstrated that there is a reduction in the effects of Si over time and that the effects of Si were smaller in recent studies. Furthermore, was found that plants under different types of stress had similar responses to Si, suggesting that abiotic stress relief mechanisms in plants may be common among conditions of water stress, salinity, and heavy metals – the main environmental stresses studied in the literature. This study can guide future research, which should not be limited to simply evaluating the existence of any Si stress-relieving effects, but also to understand the variation that exists in these mechanisms and considered that they depend on the type of stress and the factors involved in reducing these effects.

ABSTRACT Rational management of spontaneous plants is an alternative for increasing productivity in tree crops. This study aimed to evaluate the impact of management systems between rows and under the canopy of early dwarf cashew trees on the soil chemical properties and light-fraction organic matter and cashew root systems; we also evaluated the nutrient inputs from the spontaneous plants phytomass and cashew leaves deposited on an Arenic Kandiustults. The management systems under study were disc harrowing (DH) and mechanical mowing (MM) between rows, both with clearing under the cashew canopy (crowning), and herbicide (HERB) between the rows and under the canopy (without crowning). Soil and plant samples (leaves, stems, and roots) were collected at three points: under the canopy, at the canopy projected limit, and between the rows of cashew plants, all after seven years of conducting the experiment. Soil samples collected at the layers of 0.00-0.05, 0.05-0.10, 0.10-0.20, and 0.20-0.30 m were evaluated for total organic carbon, light-fraction organic matter, and chemical attributes. Dry matter, Na, Ca, Mg, N, P, and K were determined in the spontaneous-plant phytomass from under the canopy, at the canopy projected limit, and between the rows. Results showed that between rows of cashew trees there are higher phytomass input and increases in the light fraction of organic matter, pH and Mg2+ in the soil in the treatment MM. Not removing crop residues or spontaneous plants by crowning promoted accumulation of organic material and higher contents of nutrients under the canopy. The management of spontaneous plants and also soil surface under the canopy of the cashew plants had a great influence on productivity. The crowning, used in MM and DH, led to lower productivity, 1,171.87 and 594.97 kg ha-1, respectively, when compared with the absence of crowning (HERB), which resulted in productivity of 1,363.80 kg ha-1. The practice of crowning is not recommended for soil management systems in dwarf cashew crops.

Abstract The biota of the humid mountain ranges of the Brazilian semiarid is still poorly understood. In order to fill this scientific gap, we carried out an extensive survey along altitudinal ranges (400m - 1,000 m) on both the windward and the leeward slopes of the Baturité Mountain Range, in the state of Ceará state. We registered 400 plant species and 92 families. The Myrtaceae (36 spp.), Fabaceae (25 spp.), Rubiaceae (20 spp.) and Bromeliaceae (15 spp.) families predominated on the windward slope; while Fabaceae (19 spp.), Myrtaceae (14 spp.) and Euphorbiaceae (11 spp.) were the most abundant on the leeward slope. As we expected, the species richness of trees, shrubs, subshrubs, epiphytes and terrestrial herbs was positively correlated with the altitude (R2 > 0.60). Above 800 m, we registered 273 species exclusive to the windward slope, 81 exclusive to the leeward slope, and 46 shared species. Therefore, management actions must consider the spatial heterogeneity, distribution and taxa richness.

ABSTRACT Forest cover in areas degraded by mining is an alternative way of mitigating CO2 concentrations in the atmosphere by fixing C in tree biomass. This study evaluated the growth and C stocks of forest cover in an area of bauxite mining with four sources of fertilizer. Height (Ht), diameter at ground level (DGL), and diameter at breast height (DBH) were determined in Anadenanthera peregrina (Ap), clonal Eucalyptus (Euc), and a mixed plantation of 16 native forest species (Nat) at 6, 18, 36, and 56 months of age. Trunk+bark volume, biomass, and C stock were also determined for these forest covers at 56 months of age. The fertilization treatments were a standard (SF) adopted by the company, SF plus organic fertilizer (OF), chemical fertilizer (CF), and OF+CF. Euc displayed greater values of Ht, DGL, and DBH under OF+CF and OF. Fertilization did not influence the Ht and DBH of Ap, but DGL was higher under OF+CF at 36 months compared to SF. The Ht values of Nat were influenced by fertilization at 18 months, with the lowest values under SF. The fertilization influenced the DGL of Nat at 36 and 56 months, which did not occur with DBH. The pioneer species had higher Ht, DGL, and DGB compared to non-pioneer species, regardless of the type of fertilization studied. Fertilization influenced the Ht and DGL of pioneer species at 18 and 36 months of age and only the Ht of non-pioneer species. The estimates of Euc biomass (255 Mg ha-1) and C stocks (120 Mg ha-1) under OF+OC were four times greater than in Ap and Nat, which showed no difference between themselves or the types of fertilization. The growth and estimates of volume, biomass, and C stocks of the forest cover were comparable to those of unmined areas. Euc had the greatest growth, biomass, and C stocks.

RESUMO A formação de um perfil médico resolutivo das principais necessidades de saúde da população é um desafio para as escolas médicas contemporâneas. Nesse processo, o docente médico destaca-se, visto que a prática docente na formação médica se baseia na reprodução de modelos considerados válidos, aprendidos anteriormente, e na experiência prática. Questiona-se, então, a aptidão pedagógica do médico ao exercício docente, uma vez que a relação professor-acadêmico se dá em esferas diferentes da relação médico-paciente, partindo da necessidade de entender quais caminhos os docentes buscam para adquirir habilidades específicas à docência. Objetivo Realizar uma revisão integrativa acerca da formação pedagógica dos médicos no contexto da docência. Métodos Revisão integrativa da literatura, não observacional, descritiva. Inicialmente, buscaram-se estudos nas bases de dados Scientific Electronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs), US National Library of Medicine e National Institutes of Health (PubMed) e na Cochrane Library com auxílio do operador booleano e dos seguintes descritores: Health Human Resource Training; Faculty, Medical e Education, Medical, Continuing. Os critérios de inclusão foram: artigos gratuitos, completos, publicados entre 2012 e 2016, em português, espanhol e inglês. Resultados Nas quatro bases de dados, encontraram-se 24 artigos relacionados ao tema da pesquisa. Após leitura exaustiva dos artigos encontrados, apenas cinco convergiam e respondiam à questão norteadora levantada na reflexão inicial. As estratégias e metodologias de ensino e a avaliação dos processos de supervisão clínica na construção do saber técnico dos estudantes aparecem como tópicos importantes no aprender e exercer a docência. Além disso, emerge, nessas discussões, a necessidade de programas de educação continuada na formação docente, bem como a construção de instrumentos avaliativos dos professores, tutores e preceptores. Conclusões Nesse modo, ressalta-se o aprimoramento contínuo na formação pedagógica dos docentes e no desenvolvimento de programas de educação permanente e o aprimoramento do corpo docente pela escola.

ABSTRACT Qualifying the medical profile to meet the population’s main health needs is a challenge for contemporary medical schools. In this process, the medical professor has a prominent place, since medical teaching practice is based on the production of models considered valid, previously learned, and the experience of medical practice. One questions, thus, the physician’s pedagogical aptitude to teach, since the professor-academic relationship occurs differently from the physician-patient relationship, starting from the need to understand which ways professors seek to acquire the teaching-specific skills. Objective To carry out an integrative review on the pedagogical training of physicians in the teaching context. Methods This is a non-observational, descriptive integrative review of the literature. Initially, we searched the databases at the Scientific Electronic Library Online (SciELO), Latin American and Caribbean Literature in Health Sciences (Lilacs), the US National Library of Medicine and the National Institutes of Health (PubMed) and the Cochrane Library with the help of the Boolean operator and the following descriptors: Health Human Resource Training; Faculty, Medical and Education, Medical, Continuing. The inclusion criteria were free, complete articles, published from 2012 to 2016, in Portuguese, Spanish and English. Results The search resulted in 24 articles those discuss the research theme. After exhaustive reading of the articles found, only five converged and answered the guiding question raised in the initial reflection. Teaching strategies and methodologies, as well as the evaluation of clinical supervision processes to construct the students’ technical knowledge appear as important topics on learning and teaching. In addition, these discussions raise professors’ need for continuing education programs, as well as the construction of evaluation tools for professors, tutors and preceptors. Conclusions This study highlights the continuous improvement in the professors’ pedagogical training and the development of permanent education programs and improvement of the faculty by the school.

ABSTRACT: Evaluating soil geochemical diversity in the Amazon Basin has been a challenge largely because most study sites have been at the edge of the basin and it is difficult to get samples in such a region. Here we show that even among the most weathered soils, physicochemical soil properties express lithology. Our results are based on topsoil samples collected from different locations in minimally disturbed areas in the state of Amazonas, Brazil. Soil properties were measured using methods which are suitable for highly developed soils. The Chemical Index Alteration and Weathering Index of Parker was calculated based on the content of metal(loid)s in soils determined by X-ray fluorescence. Descriptive statistics, Pearson correlation, and Principal Component Analysis (PCA) were performed on data. In general, Amazon rainforest soils are more deeply weathered than soils in other Brazilian biomes and tropical rainforests in Asia and Africa. The high coefficient of variation of metal(loid) contents express pedogenesis and parent material diversity. Correlation analysis indicated that the tri-pentavalent elements are strongly associated with Al and Fe contents in the topsoil. In contrast, mono-divalent elements are correlated with sand and silt fractions. According to PCA, five soil groups with defined geochemical compositions and degrees of weathering could be identified: i) acidic sandy podzolized soils; ii) acidic loamy ferralitic soils with the highest content of tri-pentavalent ions; iii) acidic clayey kaolinitic soils with low metal(loid) contents; iv) acidic loamy kaolinitic soils with low metal(loid) contents; and v) silty neutral 2:1 clay soils. This study is the first effort to analyze the geochemical diversity in Amazon rainforest soils. These data are extremely valuable in determining the geochemical background for these soil types and this region. Geochemical variability can be predicted to some extent by lithology and pedogenesis, which can be applied to define the sampling required in future studies.

ABSTRACT In irrigated soils, a continuous state of high moisture reduces resistance of the soil to applied external forces, favouring compaction. The aim of this study was to evaluate the susceptibility to compaction of developed calcareous soils in irrigated annual and perennial cropping systems of the Apodi Plateau, located in the Brazilian semi-arid region. Four areas of irrigated crops were evaluated: banana after two (B2) and 15 (B15) years cultivation, pasture (P), and a corn and beans succession (MB), as well as the reference areas for soil quality and corresponding natural vegetation (NVB2, NVB15, NVP and NVMB). Samples were collected at layers of 0.00-0.10 and 0.20-0.30 m; and for B2 and B15, samples were collected in the row and inter-row spaces. The following properties were determined: degree of compactness (DC), preconsolidation pressure (σp), compression index (Cc), maximum density (ρmax), critical water content (WCcrit), total organic carbon (TOC) and carbon of light organic matter (Clom). Mean values were compared by the t-test at 5, 10, 15 and 20 % probability. An increase was seen in DC at a layer of 0.20-0.30 m in MB (p<0.15), showing the deleterious effects of preparing the soil by ploughing and chiselling, together with the cumulative traffic of heavy machinery. The TOC had a greater influence on ρmax than the stocks of Clom. Irrigation caused a reduction in Cc, and there was no effect on σp at field capacity. The planting rows showed different behaviour for Cc, ρmax, and WCcrit,, and in general the physical properties displayed better conditions than the inter-row spaces. Values for σp and Cc showed that agricultural soils display greater load-bearing capacity and are less susceptible to compaction in relation to soils under natural vegetation.

RESUMO: Irrigação com água produzida, que é gerada durante a extração de petróleo bruto e gás pode ser uma opção para agricultura irrigada em regiões semi-áridas mas o efeito desta água tratada no estado nutricional das plantas e no crescimento e desenvolvimento das culturas deve ser avaliado. Com esse propósito, determinamos alterações nos aspectos nutricionais da cultura de girassol irrigado com água produzida e os efeitos na produção de biomassa e de grãos de girassol. O girassol cv. BRS 321 foi cultivado durante três ciclos em áreas irrigadas com água produzida filtrada (FPW) e tratada por osmose (OPW) e água subterrânea (GW). Ao final de cada ciclo, raízes, parte aérea e grãos foram coletados para determinar as concentrações de nutrientes. Irrigação com água produzida afetou o acúmulo de nutrientes em plantas de girassol. Irrigação com OPW promoveu acúmulo de Ca, Na, N, P e Mg. Plantas irrigadas com FPW acumularam maiores teores de Na em raízes e parte aérea, e afetou negativamente a produção de biomassa e de grãos de girassol. Os níveis de Na na parte aérea de plantas irrigadas com FPW aumentaram ao longo dos três ciclos de cultivo. Sob condições controladas, é possível reutilizar a água produzida tratada por osmose inversa na agricultura, mas necessita de mais estudos a longo prazo para compreender o efeito cumulativo, nas propriedades químicas e biológicas do solo e na produção das culturas. Estes resultados sugerem que a irrigação com água produzida tratada adequadamente, é uma boa estratégia para a sustentabilidade dos recursos hídricos.

ABSTRACT: Irrigation using produced water, which is generated during crude oil and gas recovery and treated by the exploration industry, could be an option for irrigated agriculture in semiarid regions. To determine the viability of this option, the effects of this treated water on the nutritional status of plants should be assessed. For this purpose, we examined the nutritional changes in sunflowers after they were irrigated with oil-produced water and the effects of this water on plant biomass and seed production. The sunflower cultivar BRS 321 was grown for three crop cycles in areas irrigated with filtered produced water (FPW), reverse osmosis-treated produced water (OPW), or ground water (GW). At the end of each cycle, roots, shoots, and seeds were collected to examine their nutrient concentrations. Produced water irrigation affected nutrient accumulation in the sunflower plants. OPW irrigation promoted the accumulation of Ca, Na, N, P, and Mg. FPW irrigation favored the accumulation of Na in both roots and shoots, and biomass and seed production were negatively affected. The Na in the shoots of plants irrigated with FPW increased throughout the three crop cycles. Under controlled conditions, it is possible to reuse reverse osmosis-treated produced water in agriculture. However, more long-term research is needed to understand its cumulative effects on the chemical and biological properties of the soil and crop production.

Objetivo: Avaliar o nível de radiação no ambiente de um serviço de PET/CT. Materiais e Métodos: Para a determinação dos níveis de radiação no ambiente foram utilizados dosímetros termoluminescentes TLD-100H previamente selecionados e calibrados. Estes detectores foram expostos durante 32 dias em diversos pontos estrategicamente escolhidos nas dependências do serviço e nos prédios adjacentes. Após o período de exposição, os dosímetros foram recolhidos e processados. Resultados: Em nenhum dos pontos avaliados os valores medidos ultrapassaram os limites de restrição de dose para área controlada (5 mSv/ano) ou para área livre (0,5 mSv/ano) recomendados pelas normas brasileiras. Conclusão: Com este trabalho foi possível demonstrar que todas as blindagens do serviço estão adequadas e que, consequentemente, os trabalhadores, desde que seguindo as normas de radioproteção, receberão doses abaixo da dose de restrição indicada no Brasil.

Objective: To evaluate the level of ambient radiation in a PET/CT center. Materials and Methods: Previously selected and calibrated TLD-100H thermoluminescent dosimeters were utilized to measure room radiation levels. During 32 days, the detectors were placed in several strategically selected points inside the PET/CT center and in adjacent buildings. After the exposure period the dosimeters were collected and processed to determine the radiation level. Results: In none of the points selected for measurements the values exceeded the radiation dose threshold for controlled area (5 mSv/year) or free area (0.5 mSv/year) as recommended by the Brazilian regulations. Conclusion: In the present study the authors demonstrated that the whole shielding system is appropriate and, consequently, the workers are exposed to doses below the threshold established by Brazilian standards, provided the radiation protection standards are followed.

Objetivo: O objetivo deste trabalho é avaliar a dose em pacientes submetidos a PET/CT para diagnóstico de comprometimento cognitivo leve. Materiais e Métodos: Para as medidas da dose absorvida proveniente da modalidade CT utilizaram-se detectores TLD-100 inseridos em um simulador Alderson Rando®. Os simuladores antropomórficos (versões masculina e feminina) foram submetidos aos mesmos protocolos técnicos para aquisição das imagens dos pacientes. A dose absorvida resultante da injeção do radiofármaco foi estimada por meio do modelo proposto pela ICRP 106. Resultados: A dose efetiva a que foram submetidos os pacientes com esta técnica diagnóstica foi, aproximadamente, (5,34 ± 1,99) mSv. Conclusão: Protocolos otimizados para cálculo de atividade radioativa que será injetada em cada paciente podem contribuir para a redução da dose efetiva nos pacientes durante a realização do diagnóstico de comprometimento cognitivo leve com PET/CT.

Objective: The present study was aimed at evaluating the effective radiation dose in patients submitted to PET/CT for the diagnosis of mild cognitive impairment. Materials and Methods: TLD-100 detectors inserted into an Alderson Rando® anthropomorphic phantom were utilized to measure the absorbed dose coming from the CT imaging modality. The anthropomorphic phantoms (male and female adult versions) were submitted to the same technical protocols for patients’ images acquisition. The absorbed dose resulting from the radiopharmaceutical injection was estimated by means of the model proposed by the ICRP publication 106. Results: The effective dose in patients submitted to this diagnostic technique was approximately (5.34 ± 1.99) mSv. Conclusion: Optimized protocols for calculation of radioactive activity injected into patients submitted to this diagnostic technique might contribute to reduce the effective radiation dose resulting from PET/CT in the diagnosis of mild cognitive impairment.