Aldo José Fontes-Pereira

Efeito do ultrassom terapêutico de baixa intensidade em fratura induzida em tíbia de ratos

OBJECTIVE: To analyze the possible effects of low-intensity ultrasound on induced tibia fracture of rats in a dose commonly used in physical therapy treatments. METHODS: Twenty male Wistar rats were divided into two groups with 10 animals each. In the ultrasound group (USG), the animals were submitted to bone fracture and treatment with therapeutic ultrasound (TUS). Ultrasonic parameters are: frequency of 1.0 MHz, intensity of 0.2 W/cm2, pulsed mode at 20%, applied in stationary form during 10 minutes on the fracture region, for five weeks. The control group (CG) was submitted to bone fracture but not treated with ultrasound. RESULTS: The radiographies showed better consolidation in USG compared to CG. The statistical tests for alkaline phosphatase and serum calcium did not show significant difference between groups. CONCLUSION: According to this study, TUS, applied with these parameters (not commonly used for bone therapy) accelerates bone healing, confirmed by radiography, yet the biochemical analysis was not conclusive. One reason for this inconsistency may have been some inadequacy of the biochemical protocol, currently under investigation. Level of Evidence II, Prospective comparative study.

Ultrasound method applied to characterize healthy femoral diaphysis of Wistar rats in vivo.

A simple experimental protocol applying a quantitative ultrasound (QUS) pulse-echo technique was used to measure the acoustic parameters of healthy femoral diaphyses of Wistar rats in vivo. Five quantitative parameters [apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), time slope of apparent backscatter (TSAB), integrated reflection coefficient (IRC), and frequency slope of integrated reflection (FSIR)] were calculated using the echoes from cortical and trabecular bone in the femurs of 14 Wistar rats. Signal acquisition was performed three times in each rat, with the ultrasound signal acquired along the femurs central region from three positions 1 mm apart from each other. The parameters estimated for the three positions were averaged to represent the femur diaphysis. The results showed that AIB, FSAB, TSAB, and IRC values were statistically similar, but the FSIR values from Experiments 1 and 3 were different. Furthermore, Pearsons correlation coefficient showed, in general, strong correlations among the parameters. The proposed protocol and calculated parameters demonstrated the potential to characterize the femur diaphysis of rats in vivo. The results are relevant because rats have a bone structure very similar to humans, and thus are an important step toward preclinical trials and subsequent application of QUS in humans.

On the Feasibility of Ultrasound Imaging Enrichment by Medium-Temperature Changes:

We describe the concept of a new imaging modality based on the tracking and dynamic modeling of local intensity changes (ICs) observed in conventional ultrasound images collected during a medium-temperature change. We computed the pixel-by-pixel IC from averaged B-mode images that exhibited different behaviors with varying temperature resulting from changes in the speed of sound, which consequently induce changes in the backscattered energy. Moreover, for each pixel, a first-order polynomial model was adjusted to the different temperature-dependent ICs. The representation of the polynomial angular parameter in 2D pixel space was used to obtain a parametric image. The results obtained by simulations and with real B-mode images indicated that this new ultrasound imaging modality was able to enhance the contrast and highlight structures that were poorly visible or even undetected in conventional images. A temperature change of 3°C was found to be sufficient to generate appropriate images with the proposed method. In addition, if a temperature change of 6°C was considered, the thermal dose, measured as the cumulative number of equivalent minutes at 43°C (CEM43°C), was 2.4 CEM43°C, which is a value that is considered safe according to the literature. We provide a proof-of-concept of a new imaging modality that opens new opportunities for the enhancement of ultrasound images and consequently contributes to improvements in ultrasound-based diagnoses. Our approach is based on images returned by commercial ultrasound scanners. Therefore, it can be implemented in any ultrasound system and is independent of specific ultrasound hardware and software data acquisition characteristics.

Monitoring bone changes due to calcium, magnesium, and phosphorus loss in rat femurs using Quantitative Ultrasound

Bone mineral density is an important parameter for the diagnosis of bone diseases, as well as for predicting fractures and treatment monitoring. Thus, the aim of the present study was to evaluate the potential of Quantitative Ultrasound (QUS) to monitor bone changes after calcium, phosphorus, and magnesium loss in rat femurs in vitro during a demineralization process. Four quantitative ultrasound parameters were estimated from bone surface echoes in eight femur diaphysis of rats. The echo signals were acquired during a decalcification process by Ethylenediaminetetraacetic Acid (EDTA). The results were compared to Quantitative Computed Tomography (QCT) and inductively coupled plasma optical emission spectrometry measurements for validation. Integrated Reflection Coefficient (IRC) reflection parameters and Frequency Slope of Reflection Transfer Function (FSRTF) during demineralization tended to decrease, while the backscattering parameter Apparent Integrated Backscatter (AIB) increased and Frequency Slope of Apparent Backscatter (FSAB) showed an oscillatory behavior with no defined trend. Results indicate a clear relation between demineralization and the corresponding decrease in the reflection parameters and increase in the scattering parameters. The trend analysis of the fall curve of the chemical elements showed a better relationship between IRC and QCT. It was possible to monitor bone changes after ions losses, through the QUS. Thus, it is an indication that the proposed protocol has potential to characterize bone tissue in animal models, providing consistent results towards standardization of bone characterization studies by QUS endorsing its use in humans.

EXPLORING CORTICAL BONE DENSITY THROUGH THE ULTRASOUND INTEGRATED REFLECTION COEFFICIENT

ABSTRACT Objective: This work evaluates the relationship between ultrasonic reflection and bone density from fourteen cylindrical bovine cortical bone samples (3.0-cm thick). Methods: Twenty US reflection signals per sample were acquired along the bone surface (2.0-mm step). The Integrated Reflection Coefficient (IRC) from each signal was compared to Quantitative Computed Tomography (QCT). Results: Seven IRC and QCT curves presented Pearsons Correlation R-values above 0.5. For weak correlation curves, QCT and IRC showed similar trends in several segments. Conclusion: IRC was sensitive to bone density variation. Level of Evidence: Experimental Study, Investigating a Diagnostic Test.

Quantitative assessment of female sexual function correlated with the contraction of the pelvic floor muscles

A sexualidade influencia o bem-estar de cada individuo e os musculos do assoalho pelvico (MAP) exercem papel importante na resposta sexual. O objetivo desta pesquisa foi verificar a possivel relacao da funcao sexual feminina com o grau de contracao dos MAP. A amostra foi composta por dez mulheres saudaveis, sem queixas de disfuncoes sexuais e/ou ginecologicas, sexualmente ativas, na faixa etaria de 21 a 40 anos. Foi utilizado o questionario Female Sexual Function Index (FSFI) para verificar a funcao sexual e um perineometro para mensurar a contracao dos MAP em mulheres na posicao de decubito dorsal. A partir da classificacao do grau de contracao dos musculos do assoalho pelvico, as voluntarias foram distribuidas em tres grupos: G1 (Grau I), G2 (Grau II) e G3 (Grau III). De acordo com os grupos de contracao, foi verificado se havia diferenca entre os escores do FSFI entre os grupos e, tambem, o grau de contracao foi correlacionado com o FSFI. Verificou-se que o G1 obteve escores no dominio desconforto/dor menores em comparacao ao G2 e sem diferenca estatistica com o G3. Houve uma correlacao positiva entre o indice da funcao sexual feminina e o grau de forca da musculatura do assoalho pelvico. No presente estudo foi observada que, quanto maior a forca de contracao dos MAP, melhor o indice da funcao sexual em mulheres saudaveis.

Evaluación cuantitativa de la función sexual femenina correlacionada con la contracción de los músculos del suelo pélvico

A sexualidade influencia o bem-estar de cada individuo e os musculos do assoalho pelvico (MAP) exercem papel importante na resposta sexual. O objetivo desta pesquisa foi verificar a possivel relacao da funcao sexual feminina com o grau de contracao dos MAP. A amostra foi composta por dez mulheres saudaveis, sem queixas de disfuncoes sexuais e/ou ginecologicas, sexualmente ativas, na faixa etaria de 21 a 40 anos. Foi utilizado o questionario Female Sexual Function Index (FSFI) para verificar a funcao sexual e um perineometro para mensurar a contracao dos MAP em mulheres na posicao de decubito dorsal. A partir da classificacao do grau de contracao dos musculos do assoalho pelvico, as voluntarias foram distribuidas em tres grupos: G1 (Grau I), G2 (Grau II) e G3 (Grau III). De acordo com os grupos de contracao, foi verificado se havia diferenca entre os escores do FSFI entre os grupos e, tambem, o grau de contracao foi correlacionado com o FSFI. Verificou-se que o G1 obteve escores no dominio desconforto/dor menores em comparacao ao G2 e sem diferenca estatistica com o G3. Houve uma correlacao positiva entre o indice da funcao sexual feminina e o grau de forca da musculatura do assoalho pelvico. No presente estudo foi observada que, quanto maior a forca de contracao dos MAP, melhor o indice da funcao sexual em mulheres saudaveis.

Avaliação quantitativa da função sexual feminina correlacionada com a contração dos músculos do assoalho pélvico

A sexualidade influencia o bem-estar de cada individuo e os musculos do assoalho pelvico (MAP) exercem papel importante na resposta sexual. O objetivo desta pesquisa foi verificar a possivel relacao da funcao sexual feminina com o grau de contracao dos MAP. A amostra foi composta por dez mulheres saudaveis, sem queixas de disfuncoes sexuais e/ou ginecologicas, sexualmente ativas, na faixa etaria de 21 a 40 anos. Foi utilizado o questionario Female Sexual Function Index (FSFI) para verificar a funcao sexual e um perineometro para mensurar a contracao dos MAP em mulheres na posicao de decubito dorsal. A partir da classificacao do grau de contracao dos musculos do assoalho pelvico, as voluntarias foram distribuidas em tres grupos: G1 (Grau I), G2 (Grau II) e G3 (Grau III). De acordo com os grupos de contracao, foi verificado se havia diferenca entre os escores do FSFI entre os grupos e, tambem, o grau de contracao foi correlacionado com o FSFI. Verificou-se que o G1 obteve escores no dominio desconforto/dor menores em comparacao ao G2 e sem diferenca estatistica com o G3. Houve uma correlacao positiva entre o indice da funcao sexual feminina e o grau de forca da musculatura do assoalho pelvico. No presente estudo foi observada que, quanto maior a forca de contracao dos MAP, melhor o indice da funcao sexual em mulheres saudaveis.