Un nuevo método sencillo y exacto para medir el tamaño de los pólipos durante la colonoscopia / A simple new method to accurately measure the size of polyps during colonoscopy

Resumen Introducción: tradicionalmente, los pólipos colónicos se miden empíricamente por estimación visual y con las pinzas de biopsia, aunque dichos métodos son inexactos. Diferentes métodos han sido investigados, pero no tienen la exactitud esperada. Por lo anterior, se realizó este trabajo para construir un algoritmo que permitiera medir los pólipos a partir de fotografías tomadas con el colonoscopio. Materiales y métodos: el trabajo se realizó en tres fases. En la primera, se construyó un algoritmo en el programa MATLAB. Se capturaron fotos en formato JPG con el colonoscopio. En la segunda fase, con el algoritmo se midieron imágenes de objetos con tamaños conocidos para verificar la exactitud del algoritmo. Después de verificar la exactitud, fue sometida al algoritmo la fotografía de los pólipos del colon. En la tercera fase, se utilizaron imágenes de pólipos previamente enviadas a tres expertos. Todas las fotografías fueron tomadas con el colonoscopio Olympus Exera II. Resultados: en los objetos menores de 5 mm, el algoritmo sobreestimó el tamaño entre 0,11 y 0,08 mm; en los mayores de 5 mm, sobreestimó el tamaño entre 0,25 mm y 1,76 mm en los de 22 mm. Los expertos sobrestimaron los tamaños de manera importante. En los pólipos de 7, 8 y 9 mm, los expertos dijeron que medían 12, 15 y 18 mm, respectivamente. Conclusión: el algoritmo desarrollado tiene adecuada exactitud para medir pólipos colónicos. Por su fácil consecución y utilización, podría ser una herramienta para solucionar la dificultad de medir pólipos durante una colonoscopia.

Abstract Introduction: Traditionally, colon polyps' measurements have been empirically estimated visually and with biopsy forceps, but neither method is inaccurate. Other methods have been studied but have not had the accuracy expected. The research reported here was undertaken to address this issue by building an algorithm for measure polyps from photographs taken through a colonoscope. Materials and methods: The study was done in three phases. First, an algorithm was built in MATLAB, and photos taken with a colonoscope were stored in the JPG format. In the second phase, images of objects with known sizes were checked against the algorithm to verify its accuracy. After verification of the algorithm's accuracy, photographs of colon polyps were measured using the algorithm. In phase 3, images of polyps previously sent to three experts were measured with the algorithm. All photographs were taken with an Olympus Exera II Colonoscope. Results: For objects smaller than 5 mm, the algorithm overestimated sizes by 0.11 to 0.08 mm. For those greater than 5 mm, it overestimated sizes by 0.25 mm to 1.76 mm in those of 22 mm. The experts seriously overestimated sizes. They estimated that 7 mm polyps measured 12 mm, 8 mm polyps measured 15 mm, and 9 mm polyps measured 18mm. Conclusion: The algorithm developed is sufficiently accurate for measuring colon polyps and is easy to obtain and relatively easy to use. It could become a tool for overcoming the difficulty of measuring polyps during a colonoscopy.

Ultrassonografia testicular em caprinos jovens da raça Alpina / Testicular ultrasonography in young Alpine goats

Objetivou-se com este trabalho observar as mudanças do parênquima testicular de acordo com o fotoperíodo e com a faixa etária dos animais por meio da ecotextura testicular e a viabilidade do uso do ultrassom na avaliação testicular. Foram utilizados 4 animais desde o 6° até o 13° mês de idade. Os exames ecográficos foram realizados a cada 15 dias para avaliar a ecotextura testicular. O parênquima testicular mostrou-se moderadamente ecogênico e homogêneo. Foi observado comportamento semelhante na ecotextura testicular durante o período de avaliação, sendo maior no 8º mês de idade, quando o volume testicular também foi maior; tais mudanças foram relacionadas com o fotoperíodo da região. A avaliação ultrassonográfica dos testículos mostrou-se um método eficiente, capaz de detectar as mudanças no parênquima testicular ao longo do tempo, e como ferramenta alternativa para diferenciação de condições normais e patológicas em caprinos...

The purpose of this study was to observe changes in the testicular parenchyma of male goats. Changes were observed in terms of goat age, evaluating the echotexture and ultrasound viability in the testicles. Four animals were used, ranging from six to 13 months of age. The echographic examinations were performed every 15 days to assess echotexture of the testicle. The testicular parenchyma appeared moderately echogenic and homogeneous. Similar results were observed in testicular echotexture during the evaluation period. The highest results appearing during the eighth month of age, when the testicular volume was also highest; such changes were related to the regional photoperiod. The ultrasound evaluation of the testicles was shown to be an effective method, ultimately capable of detecting changes in testicular parenchyma over time, being an alternative to differentiation normal and pathological conditions in goats...

Valoración digital de índices de atenuación radiológica de estructuras anatómicas normales y materiales dentales observables en imágenes panorámicas / Digital valuation of radiologic attenuation indexes of normal anatomical structures and dental materials observed in panoramic images

Introducción: el desarrollo tecnológico vertiginoso, aplicado al diagnóstico mediante imágenes radiológicas digitales ha abierto una nueva dimensión en la valoración cualitativa y cuantitativa de los componentes esqueléticos y dentales así como también en la verificación y control de tratamientos con materiales biocompatibles. El conocimiento del perfil matemático estándar de las estructuras naturales y los materiales biodentales utilizados, permite la detección de alteraciones estructurales ya sea por patologías como también fallas en los materiales utilizados en la reparación de los daños odontológicos más comunes. Métodos: mediante radiología digital directa (RDD), se analizó el perfil de valor numérico de atenuación de estructuras anatómicas y materiales dentales más comúnmente manifiestos en imágenes panorámicas. Resultados y conclusiones: la escala tonal de grises varío desde el 0 hasta el 255, valores correspondientes a los tonos de píxeles.

Introduction: the fast technological development applied to medical digital images has opened a new dimension in the qualitative and quantitative assesment of dental and skeletal components, as well as treatment control when biomaterials are used. The knowledge of the Mathematical Standard Profiles and biomaterials used allows the detection of structural alterations such as pathology and dental materials failures. Methods: direct digital panoramic images were taken and the numerical absoprtion value of anatomical structures and dental materials most commonly seen in panoramic images were analyzed. Results and conclusions: the gray tone scale varied from 0 to 255, corresponding to the value of the tones of pixels observable and dependent on electric current in Digital radiographic technology applied to maxillofacial area.

Estudo radiográfico da densidade óssea, utilizando diferentes penetrômetros de alumínio / A radiographic study of bone density using different aluminum stepwedges

Esta pesquisa objetivou comparar a densidade relativa de fragmentos ósseos mandibulares de suínos com a de penetrômetros de alumínio e comparar a densidade entre dois penetrômetros. Utilizou-se dois penetrômetros de alumínio de diferentes fabricações, denominados de P1 e P2, constituídos por 16 degraus, com 0,3 mm de espessura e 5 fragmentos da cortical vestibular de mandíbulas secas de suínos. Os fragmentos e os penetrômetros foram radiografados com filmes Ultra-speed, tempo de exposição de 0,32 segundos e distância focal de 25 cm. As radiografias foram processadas em uma câmara escura pelo método de tempo e temperatura, e posteriormente digitalizadas. As imagens foram analisadas por meio da ferramenta histograma do programa Image Tool, de acordo com áreas selecionadas nos fragmentos ósseos e nos penetrômetros. A análise dos resultados pelos testes estatísticos ANOVA e Tukey, mostrou que não houve diferenças estatisticamente significantes dos valores da densidade entre os fragmentos ósseos e o degrau 3 (3,6 mmEq/Al) do penetrômetro P1 (p > 0,05). Observou-se que houve diferenças estatisticamente significantes entre os valores da densidade dos fragmentos ósseos e dos degraus 1 (3 mmEq/Al), 2 (3,3 mmEq/Al) e 3 (3,6 mmEq/Al) do penetrômetro P2 (p < 0,05). Finalmente, constatou-se que houve diferenças estatisticamente significantes dos valores da densidade relativa dos degraus 1 (3 mmEq/Al), 2 (3,3 mmEq/Al) e 3 (3,6 mmEq/Al), entre os penetrômetros P1 e P2 (p < 0,05). Concluiu-se que foi possível atribuir valores em milímetros equivalentes de alumínio à densidade relativa dos fragmentos ósseos, e que existe diferença da densidade em pixels entre penetrômetros constituídos pelo mesmo metal, porém com fabricações diferentes, tornando-se necessário a sua padronização quando utilizado como material de referência para estudos de densidade óssea.

This research aimed to compare the relative density of swine?s mandible bone ships with aluminum stepwedge and to compare the density of two different stepwedges. It was used two aluminum stepwedges on different manufacturers, P1 and P2, and 5 fragments from bucal cortical of the dry swine?s mandible. The bone chips and the stepwedges were radiographed using Ultra-speed films, with an exposure time of 0.32s and a focus-film distance of 25 cm. The films were processed manually by the time/temperature method. After that, they were digitalized and analyzed using the histogram tool, from Image Tool software. The data were analyzed by statistics tests of ANOVA and Tukey (5%). The results showed that there was no estatistical differences between the densities of the bone chips and the step number 3 (3,6 mmEq/Al) of the P1 stepwedge (p > 0.05). There were statistical differences between the densities of the bone chips and the steps number 1 (3,0 mmEq/Al), number 2 (3,3 mmEq/Al) and number 3 (3,6 mmEq/Al) of the P2 stepwedge (p < 0.05). Finally, there were statistical differences of densities of the steps number 1, 2 and 3 between both stepwedges (p < 0.05). It was concluded that it is possible to attribute values in aluminum equivalent millimeters to the relative density of bone chips and that there is difference of density in pixels between stepwedges composed with the same metal, although they are from different manufacturers. It is very important to standardize the type of stepwedge when it is used as reference material in bone density studies.

The Acceptance Testing of 5 Mega Pixels Primary Electronic Display Devices and the Study of Quality Control Guideline Suitable for Domestic Circumstance / 의학물리

In June 2005, Yonsei University Medical Center, Severance Hospital upgraded a full-PACS system by adding twenty (5 mega pixels) Totoku ME511L flat panel LCD display devices for diagnostic interpretation purposes. Here we report upon the quantitative (or visual) acceptance testing of the twenty Totoku ME511L display devices for reflection, luminance response, luminance spatial dependency, resolution, noise, veiling glare, and display chromaticity based on AAPM TG 18 report. The tools used in the tests included a telescopic photometer, which was used as a colorimeter, illuminance meter, light sources for reflection assessment, light-blocking devices, and digital TG18 test patterns. For selected 8 flat panel displays, mean diffuse reflection coefficient (Rd) was 0.019+/-0.02 sr(-1). In the luminance response test, luminance ratio (LR), maximum luminance difference (Lmax), and deviation of contrast response were 550+/-100, 2.0+/-1.9%, and 5.8+/-1.8%, respectively. In the luminance uniformity test, maximum luminance deviation was 14.3+/-5.5% for the 10% luminance of the TG18-UNL10 test pattern. In the resolution test with luminance measurement method, percent luminance (Delta L) at the center was 0.94+/-0.64%. In all cases of noise testing, rectangular target in every square in the three quadrants was visible and all 15 targets except the smallest one in the every corner pattern and the center pattern. The glare ratio (GR) was 12,346+/-1,995. The color uniformity, (u',v'), was 0.0025+/-0.0008. Also, the research results of quality control guideline of primary disply devices suitable for domestic circumstance are presented. All test results are in-line with the criteria recommended by AAPM TG18 report and are thus fully acceptable for diagnostic image interpretation. As a result, the acceptance testing schedule described provides not only an acceptance standard but also guidelines for quality control, optimized viewing conditions, and a means for determining the upgrading time of LCD display devices for diagnostic interpretation.