Effect of technical parameters on dose and image quality in a computed radiography system

The discovery of X-rays was undoubtedly one of the greatest stimulus for improving the efficiency in the provision of healthcare services. The ability to view, non-invasively, inside the human body has greatly facilitated the work of professionals in diagnosis of diseases. The exclusive focus on image quality (IQ), without understanding how they are obtained, affect negatively the efficiency in diagnostic radiology. The equilibrium between the benefits and the risks are often forgotten. It is necessary to adopt optimization strategies to maximize the benefits (image quality) and minimize risk (dose to the patient) in radiological facilities. In radiology, the implementation of optimization strategies involves an understanding of images acquisition process. When a radiographer adopts a certain value of a parameter (tube potential [kVp], tube current-exposure time product [mAs] or additional filtration), it is essential to know its meaning and impact of their variation in dose and image quality. Without this, any optimization strategy will be a failure. Worldwide, data show that use of x-rays has been increasingly frequent. In Cabo Verde, we note an effort by healthcare institutions (e.g. Ministry of Health) in equipping radiological facilities and the recent installation of a telemedicine system requires purchase of new radiological equipment. In addition, the transition from screen-films to digital systems is characterized by a raise in patient exposure. Given that this transition is slower in less developed countries, as is the case of Cabo Verde, the need to adopt optimization strategies becomes increasingly necessary. This study was conducted as an attempt to answer that need. Although this work is about objective evaluation of image quality, and in medical practice the evaluation is usually subjective (visual evaluation of images by radiographer / radiologist), studies reported a correlation between these two types of evaluation (objective and subjective) [5-7] which accredits for conducting such studies. The purpose of this study is to evaluate the effect of exposure parameters (kVp and mAs) when using additional Cooper (Cu) filtration in dose and image quality in a Computed Radiography system

Small cell neuroendocrine carcinoma: a case study in gynecologic cytopathology

O presente estudo reporta o caso de uma mulher de 63 anos da qual a única informação clínica era a suspeita de um sarcoma da cérvix. Simultaneamente à colpocitologia, foram enviadas biópsias do colo e do endométrio para diagnóstico. A visualização da amostra citológica revelou vários agregados de número variável de células monótonas, com tamanho pequeno, formato redondo e citoplasma escasso, num fundo com diátese. Os núcleos apresentavam moldagem, hipercromasia, cromatina “sal-e-pimenta” e ausência de nucléolos. O aspeto microscópico das biópsias foi concordante com os achados citológicos, tendo sido igualmente identificados focos glanduliformes com características atípicas. A neoplasia mostrou expressão imunohistoquímica dos antigénios enolase neurónio-específica (neuron specific enolase, NSE), sinaptofisina e citoqueratina (clones AE1/AE3), e uma elevada atividade proliferativa demonstrada pela imunorreactividade para o marcador nuclear Ki67/Mib1. Os achados citológicos, histológicos e imunohistoquímicos foram consistentes com o diagnóstico de carcinoma neuroendócrino de pequenas células. Dos tumores cervicais, esta neoplasia maligna é das mais raras, mostrando um comportamento muito agressivo, com prognóstico muito pobre, em que as terapêuticas existentes são pouco consensuais quanto à sua eficácia. A sua etiologia ainda é estudada, podendo estar relacionada com a infeção pelo Vírus do Papiloma Humano.ABSTRACT - The present study shows the case of a 62 years old woman, whose only clinical data was a suspected cervical sarcoma. A liquid-based cytology and biopsies from the cervix and the endometrium were done and sent for diagnostic laboratory. The cytology showed numerous groups of a variable number of monotonous, small and round cells, having scarce cytoplasm in a diathesis background. The nuclei featured molding, hyperchromasia, “salt-and-pepper” chromatin and no nucleoli. Similar observations could be found with the biopsies, where atypical gland-like groups were also detected. This neoplasia showed positive immunostaining for neuron specific enolase, synaptophysin and cytokeratin (AE1/AE3 clone antibodies), and a proliferative activity demonstrated by the nuclear marker Ki67/Mib1 immunorreactivity. The cytological, histological and imunohistochemical findings were consistent with the diagnosis of a small cell neuroendocrine carcinoma. Of all the cervical tumors, this sort of malignancy is one of the rarest and has a very aggressive behavior, with poor prognosis and without effective treatment. Its cause may be related to the Human Papillomavirus infection, but this still remains in study

Effects of dual-task interventions on gait performance of patients with parkinson’s disease: a systematic review

OBJECTIVE: Parkinson’s disease is characterized by motor and non-motor symptoms that impair patients’ gait performance, especially while performing dual/concurrent tasks. These deficits impair patients’ daily function, because dual-tasking is a crucial ability in terms of everyday living. The aim of this study was to systematically review the effects of dual task interventions on gait performance of patients with Parkinson’s disease. METHOD: Studies were retrieved from MEDLINE/PubMed, LILACS and SciELO. We used the PICOS strategy to determine eligibility criteria. The search strategy included an advanced search on the included databases, using the following search query: “Parkinson’s Disease” AND “Double Task” OR “Concurrent Tasks” OR “Gait” AND “Walk”. Study selection was carried out by two independent researchers and a third one was called when consensus was needed. RESULTS: A total of 188 articles were identified: 169 articles from Medline/PubMed, 10 articles in SciELO, 8 articles in LILACS and 1 item from manual searches. A total of 56 articles were analyzed regarding the eligibility and exclusion criteria based on full text. A final total of 7 studies were included in the systematic review. CONCLUSION: The different types of dual-task interventions reported (dance, sound stimuli, visual and somatosensory) were associated to improvements in several gait performance indicators of Parkinson’s disease patients, including gait speed, stride time and length, cadence and step length. External stimuli seem to play a critical role on specific training effects on dual-task gait performance.info:eu-repo/semantics/publishedVersio

The development of trust in therapeutic communities and its impact on treatment adherence

A confiança é reconhecida como um elemento essencial para o estabelecimento da relação terapêutica, com um importante impacto na adesão ao tratamento. No entanto, existem poucos estudos e modelos teóricos que permitam a sua conceptualização e mensuração neste contexto. A presente investigação tem como objectivo estudar o desenvolvimento da confiança nas Comunidades Terapêuticas e o seu impacto na adesão ao tratamento. Foi adoptada uma metodologia mista e participaram nesta investigação, 231 sujeitos distribuídos por nove Comunidades Terapêuticas. Os resultados mostram a existência de dois níveis de confiança (na relação dos residentes com os técnicos e com as instituições) e apresentam-na como um elemento fundamental para o desenvolvimento da relação terapêutica e para a adesão ao tratamento.Trust is recognized as an essential element for the establishment of therapeutic relationship and has a major impact on treatment adherence. However, there are few studies and theoretical models which allow its conceptualization and measurement within this context. This research aims to study the development of trust in Therapeutic Communities and its impact on treatment adherence. It was adopted a mixed methodology and 231 subjects spread over nine Therapeutic Communities participated of the study. The results show the existence of two levels of trust (with the technical staff and with the institutions) and present it as a key element for developing therapeutic relationship and treatment adherence

Experimental study on RSS based indoor positioning algorithms

This work compares the performance of indoor positioning systems suitable for low power wireless sensor networks. The research goal is to study positioning techniques that are compatible with real-time positioning in wireless sensor networks, having low-power and low complexity as requirements. Map matching, approximate positioning (weighted centroid) and exact positioning algorithms (least squares) were tested and compared in a small predefined indoor environment. We found that, for our test scenario, weighted centroid algorithms provide better results than map matching. Least squares proved to be completely unreliable when using distances obtained by the one-slope propagation model. Major improvements in the positioning error were found when body influence was removed from the test scenario. The results show that the positioning error can be improved if the body effect in received signal strength is accounted for in the algorithms.Helder D. Silva is supported by the Portuguese Foundation for Science and Technology under the grant SFRBD/78018/2011.info:eu-repo/semantics/publishedVersio

Body attenuation and path loss exponent estimation for RSS-based positioning in WSN

The influence of the human body in antenna systems has significant impact in the received signal strength (RSS) of wireless transmissions. Accounting for body effect is generally considered as being able to improve position estimation based on RSS measurements. In this work we perform several experiments with a wireless sensor network, using a sensor node equipped with an inertial measurement unit (IMU), in order to obtain the relative orientation between the sensor node and multiple anchor nodes. A model of the RSS attenuation induced by the body was created using experimental measurements in a controlled environment and applied to a real-time positioning system. A path loss exponent (PLE) estimation method using RSS information from neighbor anchors was also implemented and evaluated. Weighted centroid localization (WCL) algorithm was the positioning method used in this work. When the sensor node was placed on the user’s body, accounting for body effect produced negligible improvements (6%) in the best-case scenario and consistently degraded accuracy under real conditions, whether the node was placed on the user’s body (in the order of 3%), 10 cm away (from 14% to 35%) or 20 cm away from the body (from 42% to 105%) for results in the 70th percentile. The PLE estimation method showed improvements (in the order of 11%) when the sensor node is further away from the body. Results demonstrate that the distance between sensor node and the body has an extremely important influence on the accuracy of the position estimate.This work has been supported by FCT (Fundação para a Ciência e Tecnologia) in the scope of the project UID/EEA/04436/2013. Helder D. Silva is supported by FCT under the grant SFRH/BD/78018/2011info:eu-repo/semantics/publishedVersio

Computational intelligence techniques in engineering

This article shows how CI techniques overpass the strict limits of Artificial Intelligence (AI) field and can help solving real problems from distinct engineering areas: Mechanical, Computer Science and Electrical Engineering. An introduction to each of the CI main areas is made and three systems are briefly described. The results are, in each case, very promisingN/

Displasia Torácica

Os autores descrevem um caso clínico referente a uma criança que apresentava ao nascer uma marcada desproporção toraco-abdominal,por diminuição do diâmetro torácico. O Recém-nascido (RN) fez um Síndrome de Dificuldade Respiratória (SDR) precoce com necessidade de ventilação mecânica, tendo-se verificado dificuldade na entubação traqueal. Após a extubação manteve crises frequentes de polipneia e cianose. Na sequência da investigação etiológica, verificou-se que tinha uma estenose sub glótica importante. Associando os achados clínicos verificamos tratar-se de um síndrome de Barnes, forma rara de displasia torácica