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Ultrasonography is a method of imaging that classically is used in dermatology to study changes in the hypoderma, as nodules and infectious and inflammatory processes. The introduction of high frequency and resolution equipments enabled the observation of superficial structures, allowing differentiation between skin layers and providing details for the analysis of the skin and its appendages. This paper aims to review the basic principles of high frequency ultrasound and its applications in different areas of dermatology.

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Abstract: Ultrasonography is a method of imaging that classically is used in dermatology to study changes in the hypoderma, as nodules and infectious and inflammatory processes. The introduction of high frequency and resolution equipments enabled the observation of superficial structures, allowing differentiation between skin layers and providing details for the analysis of the skin and its appendages. This paper aims to review the basic principles of high frequency ultrasound and its applications in different areas of dermatology.

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OBJECTIVE: The assessment of fracture union includes physical examination and radiographic imaging, which depend on the examiner's experience. The development of ancillary methods may avoid prolonged treatments and the improper removal of implants. Quantitative bone ultrasonometry has been studied for this purpose and will soon be included in clinical practice. The aims of the present study were to assess the feasibility of using this technique on the clavicle and to standardize its in vivo application. METHODS: Twenty adult volunteers, including 10 men and 10 women without medical conditions or a previous history of clavicle fracture, underwent axial quantitative ultrasonometric assessment using transducers in various positions (different distances between the transducers and different angulations relative to the clavicle). RESULTS: Similar values of wave propagation velocity were obtained in the different tested set-ups, which included distinct distances between the transducers and angular positions relative to the clavicle. There were significant differences only in the transducers positioned at 0° and at 5 or 7 cm apart. CONCLUSIONS: The use of bone ultrasonometry on the clavicle is feasible and the standardization of the technique proposed in this study (transducers placed at 45° and at 7 cm apart) will allow its future application in clinical trials to evaluate the healing process of diaphyseal fractures of the clavicle.

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PURPOSE: To date, few studies have validated the Prostate Imaging Reporting and Data System Version 2 (PI-RADS v. 2) for the diagnosis of prostate cancer. Our aim was to validate PI-RADS v.2 using 3 Tesla (T) MRI. MATERIALS AND METHODS: This is a retrospective study of 54 consecutive patients who underwent 3T MRI with a body-array coil for diagnostic confirmation of prostate cancer or cancer staging between June 2013 and June 2015. Sensitivity, specificity, and agreement were calculated based on a criterion of PI-RADS score = 3. Inter-examiner agreement was determined by the weighted kappa statistic. RESULTS: Histological findings were positive for cancer in 33 patients and negative in 21 patients. Considering a PI-RADS score of 3 as positive for cancer, the accuracy of each reader was 85.20% and 70.40%, respectively, and agreement coefficients were κ = 0.69 and κ = 0.35. Considering PI-RADS 3 as absence of cancer, the accuracy of each reader was 77.80% and 77.80%, respectively, and agreement was κ = 0.55 and κ = 0.54. Inter-reader agreement was moderate/good (weighted κ = 0.53; 95% confidence interval: 0.39-0.66; P = 0.038). CONCLUSION: High accuracy was obtained for the diagnosis of prostate cancer using 3T MRI with a body coil and the PI-RADS v.2 score. J. Magn. Reson. Imaging 2016;44:1354-1359.

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OBJECTIVE: The assessment of fracture union includes physical examination and radiographic imaging, which depend on the examiner’s experience. The development of ancillary methods may avoid prolonged treatments and the improper removal of implants. Quantitative bone ultrasonometry has been studied for this purpose and will soon be included in clinical practice. The aims of the present study were to assess the feasibility of using this technique on the clavicle and to standardize its in vivo application. METHODS: Twenty adult volunteers, including 10 men and 10 women without medical conditions or a previous history of clavicle fracture, underwent axial quantitative ultrasonometric assessment using transducers in various positions (different distances between the transducers and different angulations relative to the clavicle). RESULTS: Similar values of wave propagation velocity were obtained in the different tested set-ups, which included distinct distances between the transducers and angular positions relative to the clavicle. There were significant differences only in the transducers positioned at 0° and at 5 or 7 cm apart. CONCLUSIONS: The use of bone ultrasonometry on the clavicle is feasible and the standardization of the technique proposed in this study (transducers placed at 45° and at 7 cm apart) will allow its future application in clinical trials to evaluate the healing process of diaphyseal fractures of the clavicle.

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Este trabalho teve por objetivo o desenvolvimento e avaliação da eficácia de um protocolo de controle de qualidade de imagens geradas por equipamentos de ultrassom operando no modo B, que fosse de fácil implementação e que utilizasse um único objeto de testes. O protocolo proposto foi avaliado em 25 equipamentos de ultrassom utilizados em medicina obstétrica, ginecologia e clínica médica, selecionados em várias clínicas e hospitais de Curitiba, Brasil. Somente modelos de equipamentos que suportavam os três tipos padrões de transdutores (convexo, linear e endocavitário) foram incluídos nos testes. No entanto, em alguns dos equipamentos, nem todos os transdutores estavam disponíveis, totalizando 72 transdutores avaliados durante os testes. Um objeto de testes de uso geral foi utilizado para avaliar os seguintes parâmetros: resoluções laterais e axiais, profundidade de visualização e exatidão das distâncias medidas, entre outras. O protocolo foi implementado em duas partes: uma envolvendo a inspeção física do equipamento/monitor e outra para avaliação dos transdutores. Entre os resultados obtidos, pode-se destacar a efetividade e simplicidade do protocolo proposto, o qual é completamente baseado em um único objeto de testes. Considerando as normas e relatórios técnicos utilizados, para aproximadamente 86% dos transdutores avaliados, falhas foram detectadas em um ou mais indicadores de qualidade de imagem. Os resultados obtidos estão de acordo com outros estudos realizados no Brasil, mostrando que um grande número de equipamentos utilizados diariamente em clínicas e hospitais apresenta um ou mais parâmetros fora dos limites estabelecidos em normas técnicas, tornando difícil o diagnóstico médico e, consequentemente, submetendo o paciente a riscos.

This study aims the development of a quality control protocol of images generated by B-mode ultrasound equipment, being of simple implementation and making use of a single phantom, as well as the evaluation of the proposed protocol effectiveness. The proposed protocol was evaluated on 25 ultrasound equipment used in obstetric medicine, gynaecology and medical clinic, selected from several clinics and hospitals of Curitiba, Brazil. Only systems with three standard transducers (convex, linear and endocavitary types) should be selected, however for some units not all of them were available, thus a total of 72 transducers were tested. A general purpose phantom was used to evaluate the following parameters: lateral and axial resolution, deepness of visualization and accuracy between distances, among others. The protocol was implemented in two parts: one involving the physical inspection of the equipment/monitor and another for the transducers evaluation. Among the results obtained, one is highlighted by the effectiveness and simplicity of the proposed protocol, which is completely based on a single phantom. Considering the utilized standards and technical reports, for approximately 86% of the evaluated transducers, some kind of failure or problem was detected in one or more image quality indicators. The results, inaccordance to those obtained by other authors in Brazil, showed that agreat number of equipment used daily in clinics and hospitals present one or more parameters out of the standards, making the medical diagnosis difficult and consequently submitting the patient to risks.

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This study describes the development of a system for quantification of human biting forces by (1) determining the mechanical properties of an epoxy resin reinforced with carbon fiber, (2) establishing the transducer's optimal dimensions to accommodate teeth of various widths while minimizing transducer thickness, and (3) determining the optimal location of strain gages using a series of mechanical resistance and finite element (FE) analyses. The optimal strain gage location was defined as the position that produced the least difference in strain pattern when the load was applied by teeth with two different surface areas. The result is a 7.3-mm-thick transducer with a maximum load capacity beyond any expected maximum bite force (1500N). This system includes a graphic interface that easily allows acquisition and registration of bite force by any health-sciences or engineering professional.

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No método de calibração por auto-reciprocidade, a sensibilidade do transdutor é determinada a partir do conhecimento de parâmetros elétricos de excitação do transdutor (tensão e corrente), além de outras grandezas presentes no parâmetro geral de reciprocidade para ondas planas JP. O objetivo deste trabalho é validar um sistema de calibração por auto-reciprocidade, conforme a norma IEC 60866:1987. A validação foi realizada utilizando-se um padrão de referência calibrado no National Physical Laboratory (NPL) em conjunto com transdutores com freqüência central de 1,0 MHz e 2,25 MHz. Para a validação do sistema de calibração, a tensão de alimentação aplicada aos transdutores foi variada de 1 a 10 V, medidos pico a pico, na faixa de 0,80 a 1,32 MHz para o transdutor de 1,0 MHz e na faixa de 1,5 a 3,0 MHz para o transdutor de 2,25 MHz. Foram considerados válidos os pontos em freqüência cujos resultados da calibração tiveram incerteza devido à linearidade máxima menor do que 10% e incerteza combinada menor do que 9%. O sistema foi validado na faixa de 1,04 a 1,32 MHz (com base nos resultados do transdutor de 1,0 MHz) e na faixa 1,55 a 2,90 MHz (utilizando-se o transdutor de 2,25 MHz). Nas freqüências próximas à freqüência de ressonância, a incerteza combinada típica do transdutor de 1,0 MHz foi de cerca de 5%, e a do transdutor de 2,25 MHz em torno de 8%. A faixa reduzida do primeiro transdutor deu-se por restrições do sistema experimental utilizado, particularmente pelos dados de calibração do padrão de referência utilizado. O sistema se mostrou adequado e os resultados foram considerados dentro do padrão esperado.

According to the self-reciprocity calibration method, ultrasonic transducer sensitivity is depicted from the knowledge of electrical parameters of excitation (voltage and electric current), as well as other quantities expressed in the general reciprocity parameters for plane waves...

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O presente trabalho consta de uma revisão minuciosa dos métodos de calibração de hodrofones, aplicáveis tanto aos do tipo agulha quanto aos de membrana. São revistos os métodos mais utilizados, absolutos e por comparação, associados às diversas técnicas de calibração e destinadas à determinação da sensibilidade do hidrofone. Os métodos descritos são: Reciprocidade, Varredura Plana, Interferometria a laser, TDS (Time Delay Spectrometry) e da Propagação Não Linear ou da Geração de Harmônicos. É apresentado um quadro comparativo descrevendo a incerteza típica e a máxima freqüência ultra-sônica inerentes a cada um dos métodos. A calibração de hidrofones com base no Método da Reciprocidade tem incerteza típica de cerca de mais ou menos 19 por cento (1,5dB) entre 0,5 e 15 MHz. Com o Método da Varredura Plana, a incerteza é de cerca de mais ou menos 6 por cento (0,5 dB) até 5 MHz, ou mais ou menos 15 por cento (1,2 dB) até 70 MHz. Para o Método TDS, as incertezas estão em torno de mais ou menos 7 por cento (0,7 dB) até 5 MHz e de mais ou menos 14 por cento (1,1 dB) até 30 MHz. Atualmente, o método interferométrico é considerado o melhor, mas não é de largo emprego devido ao seu alto custo de implementação.

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A new device was developed to hold linear transducers for transvaginal follicle aspiration. Efficacy of follicle aspiration was compared using a linear 6 MHz and a convex 5 MHz transducer. Fifty-five cows were submitted to follicle aspiration at random days of the estrous cycle. Aspirations were conducted with linear (n=28) and convex (n=38) transducers with 18 G needles at a negative pressure corresponding to 13 ml H(2)O/min. A greater number of follicles were aspirated using convex than to linear probe (12.4 versus 7.8, respectively, P<0.05). Mean number of oocytes and recovery rates were similar for convex (5.4 and 48.6%) and linear (4.6 and 59.3%) transducers. Limited space between the linear transducer and needle guide restricted access to some portions of the ovary, reducing the number of follicles aspirated using a linear transducer. The newly developed adaptor allowed greater stability, holding the ovaries firmly against the linear transducer. This diminished mobility permitted a similar number of oocytes to be recovered with both transducers. In conclusion, this new adaptor provided a low cost alternative for routine follicle aspiration and oocyte recovery in cattle.

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