RESUMO
The menmbrane potential of myelinated axons in the resting state shows fluctuations for which the power per cycle of bandwidth is inversely proportional to frequency between I and 10,000 radians per second. Reduction of potassiulm ion flux leads to a decrease in noise power.
Assuntos
Axônios/fisiologia , Condução Nervosa/fisiologia , Animais , Anuros , Transporte Biológico Ativo , Técnicas In Vitro , Bainha de Mielina , Neuroquímica , Potássio , Cloreto de Potássio , Nós Neurofibrosos , Sódio , Cloreto de SódioRESUMO
Traumatic brain injury (TBI) is a major cause of disability and death. Speed and accuracy are vital in diagnosing TBI for which computer-aided imaging analysis may speedup and improve the efficiency of diagnosis and help reduce mortality, long-term complications, and the associated costs. However, developing such a system is challenging due to some factors such as the inherent noise associated with obtaining the images, artifacts and quality of the images. An automated system that can preliminary identify, localize and quantify the imaging features of TBI would be beneficial in guiding real-time clinical diagnosis as well as for quality assurance. In this paper we propose an automated system to segment the hematoma region from CT images. The proposed method first performs denoising and image enhancement and then by developing a Gaussian mixture model, segmentation is carried out. We show the performance of the system by comparing the results with ground truth generated by specialists.
Assuntos
Lesões Encefálicas Traumáticas , Algoritmos , Artefatos , Humanos , Interpretação de Imagem Assistida por Computador , Tomografia Computadorizada por Raios XRESUMO
For few decades digital X-ray imaging has been one of the most important tools for medical diagnosis. With the advent of distance medicine and the use of big data in this respect, the need for efficient storage and online transmission of these images is becoming an essential feature. Limited storage space and limited transmission bandwidth are the main challenges. Efficient image compression methods are lossy while the information of medical images should be preserved with no change. Hence, lossless compression methods are necessary for this purpose. In this paper, a novel method has been proposed to eliminate the non-ROI data from bone X-ray images. Background pixels do not contain any valuable medical information. The proposed method is based on the histogram dispersion method. ROI is separated from the background and it is compressed with a lossless compression method to preserve medical information of the image. Compression ratios of the implemented results show that the proposed algorithm is capable of effective reduction of the statistical and spatial redundancies.
Assuntos
Osso e Ossos/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Radiografia , Algoritmos , Compressão de Dados/métodos , Humanos , Distribuição Normal , Raios XRESUMO
Coronary artery disease (CAD) is one of the major causes of death worldwide. Today X-ray angiography is a standard method for CAD diagnosis. Usually, the quality of these images is not good enough. Noise, camera and heart motions, non-uniform illumination and even the presence of catheter are sources of quality degradation. The existence of catheter can produce difficulties in vessel extraction methods because catheter is structurally similar to arteries. In this paper we propose a fully automatic method for catheter detection and tracking during the whole angiography sequence. In this method with a vesselness map, we smooth each frame using guided filter. The catheter is detected in the first frame using Hough transform. We then fit a second order polynomial on the catheter and accurately track it throughout the sequence. Our method is tested on 25 X-ray angiography sequences where a precision of 0.9597 is achieved.
Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Algoritmos , Cateterismo Cardíaco/métodos , Cateteres Cardíacos , Angiografia Coronária/métodos , HumanosRESUMO
Preventive gnathology concerns all the procedures contributing to the maintenance of a physiologic occlusion. This demands an early recognition of patients at risk and a correct 'occlusal hygiene'. The importance of the use of preventive measures to preserve the existing functions in all patients during dental treatment is stressed.
Assuntos
Oclusão Dentária , Ortodontia Preventiva , Humanos , Motivação , Higiene Bucal/métodos , Fatores de RiscoRESUMO
For the restoration of occlusal anatomy partial gold restorations are preferred. Adhesive techniques in combination with plastic materials can also be used and are less invasive than indirect restorations. Occlusal tooth wear is becoming a major problem all over the world. This paper describes minimal invasive techniques to restore tooth wear.
Assuntos
Resinas Compostas/química , Restauração Dentária Permanente/instrumentação , Restauração Dentária Permanente/métodos , Materiais Dentários , Desgaste de Restauração Dentária , Dentaduras , Ligas de Ouro , Humanos , Estudos Longitudinais , Países Baixos/epidemiologia , Propriedades de Superfície , Abrasão Dentária/epidemiologia , Erosão Dentária/epidemiologiaRESUMO
Tooth wear is considered to be the third major threat to dental health in the industrialized parts of the world next to caries and periodontal disease. Bruxism can be a cause for excessive tooth wear. Thanks to the successes in the prevention and early treatment of the infectious dental diseases, dentitions last longer as result of which tooth wear is becoming more and more of a problem in the preservation of a physiologic dentition throughout live. Furthermore there seems to be an increasing tendency for the occurrence of severe tooth wear at very early ages. Early recognition of possible contributing factors for tooth wear by the dental team is of utmost importance to enhance success in treating the problem. Prevention of ongoing damage to the remaining tooth structure must be the starting point of every treatment plan. Repair of tooth wear is in many cases a challenge from a restorative/prosthetic perspective: esthetic and phonetic aspects play an important role along with the restorative and prosthetic choices as well as functional considerations the clinician has to deal with.