Thermography as an aid for the complementary diagnosis of nodules in the thyroid gland.

BACKGROUND: Considering the estimate that thyroid cancer will become the fourth most prevalent type of tumor, improving its diagnosis is a necessity. The gold standard for evaluating thyroid nodules is ultrasound followed by biopsy. These tests, however, have limitations, especially in nodules smaller than 0.5 cm. Dynamic infrared thermography is an imaging method that does not require ionizing radiation or contrast injection. The aim of the study was to analyze the thermal behavior of thyroid nodules through infrared thermography using the cold stress protocol. RESULTS: The Wilcoxon test showed thermal differences between groups (control and healthy, p < 0.001). The difference in the thermal behavior of the nodular tissues was evidenced by the longitudinal analysis. When comparing the nodules, it was possible to verify that the beginnings of tissue heating is significant (p = 0.001). In addition, the variability analysis showed a "well" effect, which occurred in period t-1 (pre-cooling time) to period t = 3 (time three minutes). Benign nodules had a variation ratio of 1.81 compared to malignant nodules. CONCLUSION: Benign nodules present a different thermal behavior than malignant nodules, and both present different behavior than normal tissue. For the analysis of nodules, the protocol used with cold stress, dynamic thermography and the inclusion of time t-1 were essential for the differentiation of nodules in the thyroid gland. Therefore, we recommend the continuance of these parameters for future studies. METHODS: Thirty-three individuals with nodules in the thyroid region and nine healthy individuals participated in this descriptive exploratory study. In total, 42 nodules were evaluated, 11 malignant and 31 benign. The region of interest was exposed to cold stress for 30 s. First, the image was captured before the cold stress and subsequently, the images were assessed every 30 s, over a 10-min time period after cold stress. The perfusion and the thermal behavior of the tissues were evaluated by longitudinal analysis based on the number of pixels in each time period. The statistical tests of Wilcoxon, F-Snedecor and longitudinal models would assist in data analysis.

The influence of inspiratory muscle training combined with the Pilates method on lung function in elderly women: A randomized controlled trial.

OBJECTIVE: Aging is progressive, and its effects on the respiratory system include changes in the composition of the connective tissues of the lung that influence thoracic and lung compliance. The Powerbreathe® K5 is a device used for inspiratory muscle training with resistance adapted to the level of the inspiratory muscles to be trained. The Pilates method promotes muscle rebalancing exercises that emphasize the powerhouse. The aim of this study was to evaluate the influence of inspiratory muscle training combined with the Pilates method on lung function in elderly women. METHODS: The participants were aged sixty years or older, were active women with no recent fractures, and were not gait device users. They were randomly divided into a Pilates with inspiratory training group (n=11), a Pilates group (n=11) and a control group (n=9). Spirometry, manovacuometry, a six-minute walk test, an abdominal curl-up test, and pulmonary variables were assessed before and after twenty intervention sessions. RESULTS: The intervention led to an increase in maximal inspiratory muscle strength and pressure and power pulmonary variables (p<0.0001), maximal expiratory muscle strength (p<0.0014), six-minute walk test performance (p<0.01), and abdominal curl-up test performance (p<0.00001). The control group showed no differences in the analyzed variables (p>0.05). CONCLUSION: The results of this study suggest inspiratory muscle training associated with the Pilates method provides an improvement in the lung function and physical conditioning of elderly patients.

The influence of inspiratory muscle training combined with the Pilates method on lung function in elderly women: A randomized controlled trial

OBJECTIVE: Aging is progressive, and its effects on the respiratory system include changes in the composition of the connective tissues of the lung that influence thoracic and lung compliance. The Powerbreathe® K5 is a device used for inspiratory muscle training with resistance adapted to the level of the inspiratory muscles to be trained. The Pilates method promotes muscle rebalancing exercises that emphasize the powerhouse. The aim of this study was to evaluate the influence of inspiratory muscle training combined with the Pilates method on lung function in elderly women. METHODS: The participants were aged sixty years or older, were active women with no recent fractures, and were not gait device users. They were randomly divided into a Pilates with inspiratory training group (n=11), a Pilates group (n=11) and a control group (n=9). Spirometry, manovacuometry, a six-minute walk test, an abdominal curl-up test, and pulmonary variables were assessed before and after twenty intervention sessions. RESULTS: The intervention led to an increase in maximal inspiratory muscle strength and pressure and power pulmonary variables (p<0.0001), maximal expiratory muscle strength (p<0.0014), six-minute walk test performance (p<0.01), and abdominal curl-up test performance (p<0.00001). The control group showed no differences in the analyzed variables (p>0.05). CONCLUSION: The results of this study suggest inspiratory muscle training associated with the Pilates method provides an improvement in the lung function and physical conditioning of elderly patients.

A method for generating 3D thermal models with decoupled acquisition.

BACKGROUND AND OBJECTIVE: Both thermal imaging and 3D scanning offer convenient advantages for medical applications, namely, being contactless, non-invasive and fast. Consequently, many approaches have been proposed to combine both sensing modalities in order to acquire 3D thermal models. The predominant approach is to affix a 3D scanner and a thermal camera in the same support and calibrate them together. While this approach allows straightforward projection of thermal images over the 3D mesh, it requires their simultaneous acquisition. In this work, a method for generation of 3D thermal models that allows combination of separately acquired 3D mesh and thermal images is presented. Among the advantages of this decoupled acquisition are increased modularity of acquisition procedures and reuse of legacy equipment and data. METHODS: The proposed method is based on the projection of thermal images over a 3D mesh. Unlike previous methods, it is considered that the 3D mesh and the thermal images are acquired separately, so camera pose estimation is required to determine the correct spatial positioning from which to project the images. This is done using Structure from Motion, which requires a series of interest points correspondences between the images, for which the SIFT method was used. As thermal images of human skin are predominantly homogeneous, an intensity transformation is proposed to increase the efficacy of interest point detection and make the approach feasible. Before projection, the adequate alignment of the 3D mesh in space is determined using Particle Swarm Optimization. For validation of the method, the design and implementation of a test object is presented. It can be used to validate other methods and can be reproduced with common printed circuit board manufacturing processes. RESULTS: The proposed approach is accurate, with an average displacement error of 1.41  mm (s = 0.74  mm) with the validation test object and 4.58 mm (s = 2.12  mm) with human subjects. CONCLUSIONS: The proposed method is able to combine separately a acquired 3D mesh and thermal images into an accurate 3D thermal model. The results with human subjects suggest that the method can be successfully employed in medical applications.

Influences of the signal border extension in the discrete wavelet transform in EEG spike detection

Abstract Introduction The discrete wavelet transform is used in many studies as signal preprocessor for EEG spike detection. An inherent process of this mathematical tool is the recursive wavelet convolution over the signal that is decomposed into detail and approximation coefficients. To perform these convolutions, firstly it is necessary to extend signal borders. The selection of an unsuitable border extension algorithm may increase the false positive rate of an EEG spike detector. Methods In this study we analyzed nine different border extensions used for convolution and 19 mother wavelets commonly seen in other EEG spike detectors in the literature. Results The border extension may degrade an EEG spike detector up to 44.11%. Furthermore, results behave differently for distinct number of wavelet coefficients. Conclusion There is not a best border extension to be used with any EEG spike detector based on the discrete wavelet transform, but the selection of the most adequate border extension is related to the number of coefficients of a mother wavelet.

Generation of 3D thermal models for dentistry applications.

There are a variety of medical imaging modalities available, although each modality focus into different aspects, for example: anatomical, physiological or geometrical information. This paper presents a new imaging modality (3D THERMO-SCAN) that combines anatomical computer tomography (CT) imaging slices, together with 2D infrared thermography images and 3D scanned shaped models of the area under study. Therefore, it is presented the 3D reconstructions involving a case study of a volunteer with bruxism. Some characteristics of bruxism are the hyperactivity of the chewing muscles, which changes the dynamics of microcirculation, also changing the correspondent skin's temperature. The emphasis is to show the corresponding structures, such as jaw/mandibular region that will produce either decrease or increase in temperature, which are related to bruxism and the associated use of an occlusal splint, respectively.

Pulmonary crackle characterization: approaches in the use of discrete wavelet transform regarding border effect, mother-wavelet selection, and subband reduction

Introduction Crackles are discontinuous, non-stationary respiratory sounds and can be characterized by their duration and frequency. In the literature, many techniques of filtering, feature extraction, and classification were presented. Although the discrete wavelet transform (DWT) is a well-known tool in this area, issues like signal border extension, mother-wavelet selection, and its subbands were not properly discussed. Methods In this work, 30 different mother-wavelets 8 subbands were assessed, and 9 border extension modes were evaluated. The evaluations were done based on the energy representation of the crackle considering the mother-wavelet and the border extension, allowing a reduction of not representative subbands. Results Tests revealed that the border extension mode considered during the DWT affects crackle characterization, whereas SP1 (Smooth-Padding of order 1) and ASYMW (Antisymmetric-Padding (whole-point)) modes shall not be used. After DWT, only 3 subbands (D3, D4, and D5) were needed to characterize crackles. Finally, from the group of mother-wavelets tested, Daubechies 7 and Symlet 7 were found to be the most adequate for crackle characterization. Discussion DWT can be used to characterize crackles when proper border extension mode, mother-wavelet, and subbands are taken into account.

Combining 3D models with 2D infrared images for medical applications.

Infrared images are very useful for providing physiological information, although the representation is two-dimensional. On the other hand, a 3D scanning system is able to generate precise 3D spatial models of the area under study. This paper presents a methodology for combining both imaging modalities into a single representation. The Structure from Motion (SfM) technique is used in order to find the correct infrared camera's positioning and rotations in the space. Then, those 2D infrared images generate a 3D SfM model. Following this stage, the SfM model is replaced by an accurate 3D model from a scanning system, which is wrapped around by the infrared images. The experiments performed with a volunteer's face have shown that the proposed methodology successfully reconstruct a unique 3D surface model, which is able to deliver potential clinical applications.

Galvanic vestibular stimulator for fMRI studies

INTRODUCTION: Areas of the brain that are associated with the vestibular system can be activated using galvanic vestibular stimulation. These areas can be studied through a combination of galvanic vestibular stimulation with functional magnetic resonance imaging (fMRI). In order to provide an appropriate sequence of galvanic stimulation synchronous with the MRI pulse sequence, a specific electronic device that was built and assessed is presented. METHODS: The electronic project of the GVS is divided in analog and digital circuits. The analog circuits are mounted in an aluminum case, supplied by sealed batteries, and goes inside the MRI room near to the feet of the subject. The digital circuits are placed in the MRI control room. Those circuits communicate through each other by an optical fiber. Tests to verify the GVS-MRI compatibility were conducted. Silicone (in-house) and Ag/AgCl (commercial) electrodes were evaluated for maximum balance and minimal pain sensations. fMRI experiments were conducted in eight human volunteers. RESULTS: GVS-MRI compatibility experiments demonstrate that the GVS did not interfere with the MRI scanner functionality and vice versa. The circular silicone electrode was considered the most suitable to apply the galvanic vestibular stimulation. The 1 Hz stimulation sinusoid frequency produced the biggest balance and the less pain sensations when compared to 2 Hz. The GVS was capable of eliciting activation in the precentral and postcentral gyri, in the central sulcus, in the supplementary motor area, in the middle and inferior frontal gyri, in the inferior parietal lobule, in the insula, in the superior temporal gyrus, in the middle cingulate cortex, and in the cerebellum. CONCLUSION: This study shows the development and description of a neurovestibular stimulator that can be safely used inside the MRI scanner room without interfering on its operation and vice versa. The developed GVS could successfully activate the major areas involved with multimodal functions of the vestibular system, demonstrating its validity as a stimulator for neurovestibular research. To the best of our knowledge, this is the first work that shows the development and the construction of a galvanic vestibular stimulator that could be safely used inside the MRI room.

3D thermal medical image visualization tool: Integration between MRI and thermographic images.

Three-dimensional medical image reconstruction using different images modalities require registration techniques that are, in general, based on the stacking of 2D MRI/CT images slices. In this way, the integration of two different imaging modalities: anatomical (MRI/CT) and physiological information (infrared image), to generate a 3D thermal model, is a new methodology still under development. This paper presents a 3D THERMO interface that provides flexibility for the 3D visualization: it incorporates the DICOM parameters; different color scale palettes at the final 3D model; 3D visualization at different planes of sections; and a filtering option that provides better image visualization. To summarize, the 3D thermographc medical image visualization provides a realistic and precise medical tool. The merging of two different imaging modalities allows better quality and more fidelity, especially for medical applications in which the temperature changes are clinically significant.

Image fusion improvements applied at the generation of 3D thermal models.

The application of multimodal image registration to various medical applications has been investigated. Image fusion involving 3D thermal and MRI/CT images allows the extraction of both functional and anatomical information, which may become a powerful tool to aid in clinical diagnoses. This paper presents innovations at the image fusion methodology, which currently requires that both imaging modalities are represented and visualized at the same 3D viewing projection. The proposed solution is based and compared with two different viewing projections: orthogonal and perspective. The methodology requires that the thermographic images (or photographs) are visualized in the orthogonal view, in order to match with the 2D projected images (using range images) from MRI/CT. The results obtained have shown significant improvements in the 3D thermal models, when compared and evaluated with the perspective approach. This allowed the generation of more accurate 3D models, which match both the geometry and texture (functional temperature information). Since it is desirable to combine or unify more than one imaging modality, these 3D multimodal models may have a strong impact in many clinical applications.

Fusão 3D de imagens de MRI/CT e termografia / 3D image fusion using MRI/CT and infrared images

INTRODUÇÃO: A termografia por imagem infravermelha (IR) é uma técnica para diagnóstico não-invasiva que permite a avaliação e quantificação de variações de temperatura na superfície da pele. Apesar de fornecer informações significativas para auxiliar no diagnóstico médico, esta técnica não permite avaliar det alhes anatômicos da região sendo analisada. Este artigo apresenta uma nova metodologia para realizar a fusão entre diferentes modalidades de imagens, tais como ressonância magnética (MRI) ou tomografia computadorizada por raios X (CT), juntamente com imagens de termografia infravermelha. MÉTODOS: Para a construção do modelo 3D, primeiramente são adquiridas as imagens por ressonância magnética (MRI) ou tomografia computadorizada (CT) e um conjunto de imagens térmicas da região de interesse. Em seguida, realiza-se o registro utilizando as projeções 2D (dos planos tomográficos) com as imagens térmicas. Após o registro, as imagens térmicas são combinadas e projetadas sobre o modelo 3D das imagens de MRI ou CT. RESULTADOS: O resultado é uma imagem 3D que combina informação de duas modalidades de imagens médicas diferentes. A combinação dessas duas modalidades de imagens médicas disponibiliza uma nova técnica de imagem 3D que agrupa informações anatômicas (MRI ou CT) e funcionais (variações de temperatura na superfície do corpo). CONCLUSÃO: Os resultados obtidos até o momento com essa nova metodologia indicam que ela pode auxiliar em diagnósticos médicos.

INTRODUCTION: Infrared (IR) thermal imaging is a non-invasive and diagnostic technique that allows evaluation and quantification based on the temperature changes of the skin surface. It provides significant information for clinical diagnosis; however this technique does not present the anatomical details of the region under inspection. In this work, it is presented an innovative image fusion method between different imaging modalities, such as magnetic resonance images (MRI) or X-ray computed tomography (CT), together with IR thermal images. METHODS: Firstly, in order to build the 3D model, the MRI or CT images and the IR thermal images (from the region of interest) are acquired. Then, based on the tomographic planes (image slices), the 2D projections are generated, and the IR images are registered accordingly. Next, the already registered IR set of images are combined and projected over the 3D MRI or CT model. RESULTS: The result is a 3D fused image that combines the information contents from the two different medical imaging modalities. The combination of these two medical imaging modalities offers a new 3D imaging technique that combines anatomical (MRI or CT) and functional (the body's surface temperature) information. CONCLUSION: The results obtained up to now with this new methodology indicate that it can aid in medical diagnosis.

Avaliação da qualidade de imagens de equipamentos de ultrassom modo B / Image quality evaluation of B-mode ultrasound equipment

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.

A computer tool for the fusion and visualization of thermal and magnetic resonance images.

The measurement of temperature variation along the surface of the body, provided by digital infrared thermal imaging (DITI), is becoming a valuable auxiliary tool for the early detection of many diseases in medicine. However, DITI is essentially a 2-D technique and its image does not provide useful anatomical information associated with it. However, multimodal image registration and fusion may overcome this difficulty and provide additional information for diagnosis purposes. In this paper, a new method of registering and merging 2-D DITI and 3-D MRI is presented. Registration of the images acquired from the two modalities is necessary as they are acquired with different image systems. Firstly, the body volume of interest is scanned by a MRI system and a set of 2-D DITI of it, at orthogonal angles, is acquired. Next, it is necessary to register these two different sets of images. This is done by creating 2-D MRI projections from the reconstructed 3-D MRI volume and registering it with the DITI. Once registered, the DITI is then projected over the 3-D MRI. The program developed to assess the proposed method to combine MRI and DITI resulted in a new tool for fusing two different image modalities, and it can help medical doctors.

Dual photon absorptiometry using a gadolinium-153 source applied to measure equine bone mineral content.

The application of the dual photon absorptiometry (DPA) technique, using gadolinium-153 as the photon source, to evaluate the bone mineral density (BMD) of the third metacarpal bone of horses is presented. The radiation detector was implemented with a NaI(TI) scintillator coupled to a 14 stage photomultiplier. A modular mechanical system allows the position of the prototype to be adjusted in relation to the animal. A moveable carrier makes it possible to scan the third metacarpal with a velocity adjustable between 1 and 12 mm s(-1), in steps of 1 mm s(-1), for a total distance of 250 mm. The prototype was evaluated with a phantom of the third metacarpal bone made of perspex and aluminium, and in vitro with a transverse slice of the third metacarpal bone of a horse. The tests showed that the prototype has an accuracy and precision of, approximately, 10% and 6%, respectively, for a 6 s acquisition time. Preliminary studies carried out in three foals from birth to one year of age indicated that the prototype is well suited to in vivo and in situ analysis of the BMD of the third metacarpal bones of horses, making it possible to evaluate the changes of BMD levels on a monthly basis. Also, results indicated an exponential behaviour of the BMD curve during the first year of life of the studied horses.

Sistema automático para contagem de colônias em placas de Petri / Automatic system for colonies counting in Petri dishes

Esse trabalho apresenta o projeto e os testes de um protótipo de um instrumento simples, compacto e de baixo custo, para a contagem de Unidades Formadoras de Colônias (UFCs) em placas de petri. O protótipo é composto por um sistema de iluminação, uma câmera CCD, uma placa de aquisição de vídeo e um microcomputador IBM/PC ou compatível. O sistema de iluminação com LEDs é inovador e possibilita a aquisição de imagens das placas de petri com excelente contraste entre as colônias e o background. Essa característica possibilitou o desenvolvimento de um algoritmo de processamento digital de imagens simples, rápido e eficaz. O programa adquire e calcula a média de vinte imagens de uma placa de petri e utiliza o método background subtraction para separar as colônias de bactérias do restante da imagem e atenuar pequenas diferenças de iluminação. A imagem é então limiarizada e as UFCs contadas com um algoritmo recursivo capaz de localizar e determinar a dimensão, em pixels, de cada uma das colônias. Os resultados dos vários testes realizados durante o desenvolvimento demonstraram que o instrumento é capaz de contar as UFCs com área superior a 0,8mm2, sendo que o coeficiente de correlação entre os resultados obtidos com o método de contagem convencional e a contagem feita pelo protótipo é superior a 0,99