A New Approach to Classify Cardiac Arrythmias Using 2D Convolutional Neural Networks.

Cardiovascular diseases are the number one cause of death worldwide. Detecting cardiovascular diseases in its early stages could effectively reduce the mortality rate by providing timely treatment. In this study, we propose a new methodology to detect arrythmias, using 2D Convolutional Neural Networks. The main characteristic of the proposed methodology is the use of 15 x15 pixels gray-level images, containing the values of a heartbeat of the ECG signal. This work aims to detect 17 arrythmias. To validate and test the proposed methodology, MIT-BIH database, the main benchmark database available in literature, was used. When compared to other results previously published, the obtained precision, 92.31%, is in the state-of-the-art.Clinical Relevance- The presented work provides an automatic method to detect arrythmias in ECG signals by a new methodology.

Using Convolutional Neural Networks for Classification of Bifurcation Regions in IVOCT Images.

Optical Coherence Tomography (OCT) technology enabled the experts to analyze coronary lesions from high-resolution intravascular images. Studies have shown the relationship between bifurcation regions and a higher occurrence of wall thickening and lesions in these areas. Some level of automation could benefit experts, since examining pullback frames is a laborious and time-consuming task. Although Convolutional Neural Networks (CNN) have shown promising results in classification tasks of medical images, we did not identify the use of CNN's in IVOCT images to classify bifurcation regions in the literature. In this work, we evaluated a CNN architecture in the bifurcation classification task trained with IVOCT images from 9 pullbacks from 9 different patients. We used data augmentation to balance the dataset, due to the low amount of bifurcation-labeled frames. Our classification results are comparable to other works in the literature, presenting better result in AUC (99.70%).

A new method for recognizing hand configurations of Brazilian gesture language.

This paper describes a new method for recognizing hand configurations of the Brazilian Gesture Language - LIBRAS - using depth maps obtained with a Kinect® camera. The proposed method comprised three phases: hand segmentation, feature extraction, and classification. The segmentation phase is independent from the background and depends only on pixel depth information. Using geometric operations and numerical normalization, the feature extraction process was done independent from rotation and translation. The features are extracted employing two techniques: (2D)2LDA and (2D)2PCA. The classification is made with a novelty classifier. A robust database was constructed for classifier evaluation, with 12,200 images of LIBRAS and 200 gestures of each hand configuration. The best accuracy obtained was 95.41%, which was greater than previous values obtained in the literature.

Breast tumor classification in ultrasound images using neural networks with improved generalization methods.

Mammography, scintimammography and ultrasound images have been used to increase the specificity of breast cancer image diagnosis. Concerning breast cancer image diagnosis with ultrasound, some results found in the literature show better performance of morphological features in breast cancer lesion differentiation and that a reduced set of features shows a better performance than a large set of features. In this study we evaluated the performance of neural network classifiers, with different training stop criteria: mean square error, early stop and regularization. The last two criteria were developed to improve neural network generalization. Different sets of morphological features were used as neural network inputs. Training sets comprised of 22, 8, 7, 6, 5 and 4 features were employed. To select reduced sets of features, a scalar selection technique with correlation was used. The best results obtained for accuracy and area under the ROC curve were 96.98% and 0.98, respectively. The performance obtained with all 22 features is slightly better than the one obtained with a reduced set of features.

A sputum smear microscopy image database for automatic bacilli detection in conventional microscopy.

In this work, we present an image database for automatic bacilli detection in sputum smear microscopy. The database comprises two parts. The first one, called the autofocus database, contains 1200 images with resolution of 2816 × 2112 pixels. This database was obtained from 12 slides, with 10 fields per slide. Each stack is composed of 10 images, with the fifth image in focus. The second one, called the segmentation and classification database, contains 120 images with resolution of 2816×2112 pixels. This database was obtained from 12 slices, with 10 fields per slice. In both databases, the images were acquired from fields of slides stained with the standard Kinyoun method. In both databases, accordingly to the background content, the images were classified as belonging to high background content or low background content. In all 120 images of segmentation and classification database, the identified objects were enclosed within a geometric shape by a trained technician. A true bacillus was enclosed in a circle. An agglomerated bacillus was enclosed by a rectangle and a doubtful bacillus (the image focus or geometry does not allow a clear identification of the object) was enclosed by a polygon. These marked objects could be used as a gold standard to calculate the accuracy, sensitivity and specificity of bacilli recognition.

[Ultrasonically guided needle biopsy in malignant focal solid nodules of the liver]. / Biopsia percutânea guiada por ultra-som em lesões nodulares sólidas focais malignas do fígado.

In the most of the cases, the diagnosis of focal solid hepatic lesions are performed by ultrasonography, computed tomography, magnetic resonance and hepatic angiography imagig. However, the distinction between benign and malignant neoplasias, sometimes is made after liver biopsy. This report is about 32 of these lesions, diagnosed after guided liver biopsy by ultrasonography. The efficacy of this propedeutic method, minimally invasive, is defined emphasizing that there are no mortality and low levels of morbidity.

[Hepatic hemangioma. Analysis of 103 cases. Clinical considerations and imaging methods]. / Hemangiomas hepáticos. Análise de 103 casos. Considerações clínicas e dos métodos de imagem.

Hemangiomas are the most common benign vascular tumor found in the liver. In this study, 103 cases of hepatic hemangiomas were analysed in a retrospective manner. Image aspects such as those seen in ultrassonography, computed tomography, nuclear magnetic resonance and arteriography are discussed. The incidence was higher amongst the female sex, between individuals from 40 to 60 years old, which presented predominantly without symptoms (66%) and localized mainly in the right hepatic lobe (74%). The meaning of those aspects, when adopted, permits the clinicians to differentiate benign from malignant nodular lesions in the liver.

[Intrahepatic and subcapsular hematoma of the liver after hepatic biopsy under laparoscopy. Contribution of ultrasonography]. / Hematoma intra-hepático e subcapsular do fígado após biopsia hepática sob visão laparoscópica. Contribuição ao seu estudo através da ultra-sonografia.

Over the last few years, ultrasound became important in characterization of space -occupying solid lesions of the liver. Recently, Canadian authors using this method, described a 23% incidence of intrahepatic or subcapsular hematoma after liver biopsy. We prospectively evaluated the incidence of this complication after liver biopsy under laparoscopic guidance in 8 cirrhotic patients, 7 with steatosis, 7 chronic active hepatitis and 4 with intrahepatic cholestasis. Biopsy was performed under general anesthesia provided that prothrombin activity was over 50%, serum fibrinogen was over 100% and platelets over 50.000/mm3. In none of 26 consecutive patients, was an intrahepatic or subcapsular hematoma observed.

PNEUMATOSE CISTOIDE INTESTINAL Pneumatose cistoide intestinal. Relato de um caso. / Pneumatosis cystoides intestinalis. Report of a case

Os autores discutem os aspectos clinicos e patologicos da pneumatose cistoide intestinal num homem de 61 anos de idade, enfatizando as caracteristicas clinicas, radiologicas e histologicas que a distinguem de outras doencas intestinais