Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 116.169
Filtrar
1.
Am J Orthod Dentofacial Orthop ; 156(3): 420-428, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31474272

RESUMO

INTRODUCTION: This study aimed to test the accuracy of the 3-dimensional (3D) digital dental models generated by the Dental Monitoring (DM) smartphone application in both photograph and video modes over successive DM examinations in comparison with 3D digital dental models generated by the iTero Element intraoral scanner. METHODS: Ten typodonts with setups of class I malocclusion and comparable severity of anterior crowding were used in the study. iTero Element scans along with DM examination in photograph and video modes were performed before tooth movement and after each set of 10 Invisalign aligners for each typodont. Stereolithography (STL) files generated from the DM examinations in photograph and video modes were superimposed with the STL files from the iTero scans using GOM Inspect software to determine the accuracy of both photograph and video modes of DM technology. RESULTS: No clinically significant differences, according to the American Board of Orthodontics-determined standards, were found. Mean global deviations for the maxillary arch ranged from 0.00149 to 0.02756 mm in photograph mode and from 0.0148 to 0.0256 mm in video mode. Mean global deviations for the mandibular arch ranged from 0.0164 to 0.0275 mm in photograph mode and from 0.0150 to 0.0264 mm in video mode. Statistically significant differences were found between the 3D models generated by the iTero and the DM application in photograph and video modes over successive DM examinations. CONCLUSIONS: 3D digital dental models generated by the DM smartphone application in photograph and video modes are accurate enough to be used for clinical applications.


Assuntos
Confiabilidade dos Dados , Técnica de Moldagem Odontológica , Modelos Dentários , Processamento de Imagem Assistida por Computador/métodos , Imagem Tridimensional/métodos , Projeto Auxiliado por Computador , Arco Dental , Humanos , Má Oclusão/diagnóstico por imagem , Aparelhos Ortodônticos/normas , Aparelhos Ortodônticos Removíveis , Ortodontia/normas , Fotografia Dentária , Smartphone , Software , Estereolitografia , Tecnologia Odontológica/métodos , Técnicas de Movimentação Dentária , Gravação em Vídeo
2.
Bratisl Lek Listy ; 120(9): 650-657, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31475548

RESUMO

In this contribution we present graph theoretical approach to image processing focus on biological data. We use the graph cut algorithms and extend them for obtaining segmentation of biological data. We deal with tumor brain cells and rats brain to show the existence and presence of inflammatory molecules. We introduce a completely new method for filtering of data (Tab. 3, Schema 4, Fig. 7, Ref. 13). Keywords: graph cuts, segmentation, tumore analyses of cells, computer morphometry.


Assuntos
Algoritmos , Neoplasias Encefálicas/patologia , Processamento de Imagem Assistida por Computador , Modelos Teóricos , Animais , Encéfalo/citologia , Ratos
3.
BMC Ophthalmol ; 19(1): 184, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31412800

RESUMO

BACKGROUND: With the diabetes mellitus (DM) prevalence increasing annually, the human grading of retinal images to evaluate DR has posed a substantial burden worldwide. SmartEye is a recently developed fundus image processing and analysis system with lesion quantification function for DR screening. It is sensitive to the lesion area and can automatically identify the lesion position and size. We reported the diabetic retinopathy (DR) grading results of SmartEye versus ophthalmologists in analyzing images captured with non-mydriatic fundus cameras in community healthcare centers, as well as DR lesion quantitative analysis results on different disease stages. METHODS: This is a cross-sectional study. All the fundus images were collected from the Shanghai Diabetic Eye Study in Diabetics (SDES) program from Apr 2016 to Aug 2017. 19,904 fundus images were acquired from 6013 diabetic patients. The grading results of ophthalmologists and SmartEye are compared. Lesion quantification of several images at different DR stages is also presented. RESULTS: The sensitivity for diagnosing no DR, mild NPDR (non-proliferative diabetic retinopathy), moderate NPDR, severe NPDR, PDR (proliferative diabetic retinopathy) are 86.19, 83.18, 88.64, 89.59, and 85.02%. The specificity are 63.07, 70.96, 64.16, 70.38, and 74.79%, respectively. The AUC are PDR, 0.80 (0.79, 0.81); severe NPDR, 0.80 (0.79, 0.80); moderate NPDR, 0.77 (0.76, 0.77); and mild NPDR, 0.78 (0.77, 0.79). Lesion quantification results showed that the total hemorrhage area, maximum hemorrhage area, total exudation area, and maximum exudation area increase with DR severity. CONCLUSIONS: SmartEye has a high diagnostic accuracy in DR screening program using non-mydriatic fundus cameras. SmartEye quantitative analysis may be an innovative and promising method of DR diagnosis and grading.


Assuntos
Retinopatia Diabética/diagnóstico , Angiofluoresceinografia/métodos , Processamento de Imagem Assistida por Computador/métodos , Retina/diagnóstico por imagem , Seleção Visual/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Adulto Jovem
4.
Medicine (Baltimore) ; 98(33): e16606, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31415352

RESUMO

OBJECTIVE: The aim of this study was to determine optimal window settings for conventional polyenergetic and virtual monoenergetic images derived from computed tomography pulmonary angiogram (CTPA) examinations of a novel dual-layer spectral detector computed tomography system (DLCT). METHODS: Monoenergetic (40 keV) and polyenergetic images of 50 CTPA examinations were calculated and the best individual window width and level (W/L) values were manually assessed. Optimized values were obtained afterwards based on regression analysis. Diameters of standardized pulmonary artery segments and subjective image quality parameters were evaluated and compared. RESULTS: Attenuation and contrast-to-noise values were higher in monoenergetic than in polyenergetic images (P≤.001). Averaged best individual W/L for polyenergetic and monoenergetic were 1020/170 and 2070/480 HU, respectively.All adjusted W/L-settings varied significantly compared to standard settings (700/100 HU) and obtained higher subjective image quality scores. A systematic overestimation of artery diameters for standard window settings in monoenergetic images was observed. CONCLUSIONS: Appropriate W/L-settings are required to assess polyenergetic and monoenergetic CTPA images of a novel DLCT. W/L-settings of 1020/170 HU and 2070/480 HU were found to be the best averaged values for polyenergetic and monoenergetic CTPA images, respectively.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Processamento de Imagem Assistida por Computador/métodos , Pulmão/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Humanos , Pneumologia/métodos , Razão Sinal-Ruído
5.
Am J Orthod Dentofacial Orthop ; 156(2): 275-282, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31375238

RESUMO

This case report describes the interdisciplinary treatment of an ectopic horizontally placed maxillary right central incisor with severe root dilaceration. The root was distally angulated and entrapped by the root of the maxillary right lateral incisor. The initial force system was aimed at an occlusal displacement and applied to the crown. During the second phase, a button was cemented onto the apex of the impacted tooth. A force from the apex to a temporary anchorage device in the palate moved the root toward the midline. Finally, a root canal and an apectomy were performed and the central incisor could be moved to its ideal position. The treatment generated a normal height of the alveolar bone and an ideal occlusion with a healthy periodontium.


Assuntos
Incisivo/cirurgia , Técnicas de Movimentação Dentária/métodos , Raiz Dentária/cirurgia , Dente Impactado/cirurgia , Dente Impactado/terapia , Fenômenos Biomecânicos , Criança , Tomografia Computadorizada de Feixe Cônico/métodos , Cavidade Pulpar , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imagem Tridimensional , Má Oclusão de Angle Classe I/terapia , Maxila/anatomia & histologia , Maxila/diagnóstico por imagem , Maxila/cirurgia , Aparelhos Ortodônticos Fixos , Extrusão Ortodôntica/métodos , Planejamento de Assistência ao Paciente , Tratamento do Canal Radicular , Coroa do Dente , Dente Impactado/diagnóstico por imagem , Resultado do Tratamento
6.
Stud Health Technol Inform ; 264: 1417-1418, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438159

RESUMO

Automated wound detection has become a common issue in health care. A broad variety of image processing algorithms already exist, but they are very power consuming on mobile devices. Meanwhile the use of machine learning algorithms is on the rise and new frameworks have been developed to use these techniques with improved on-device-performance such as Apple Core Machine Learning Interface. In this paper, we evaluate the performance of libSVM for wound detection in practice.


Assuntos
Dermatopatias , Máquina de Vetores de Suporte , Algoritmos , Humanos , Processamento de Imagem Assistida por Computador , Aprendizado de Máquina
7.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 36(4): 627-632, 2019 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-31441264

RESUMO

The quality inspection of magnetic resonance imaging (MRI) performance parameters is an important means to ensure the image quality and the reliability of diagnosis results. There are some problems in the manual calculation and eye recognition of the quality inspection parameters, such as strong subjectivity and low efficiency. In view of these facts, an automatic analysis system for MRI quality detection based on QT is proposed and implemented in C++ language. The image processing algorithm is introduced to automatically measure and calculate the quality inspection parameters. The software with comprehensive functions is designed to systematically manage the quality inspection information of MRI. The experimental results show that the automatically calculated parameters are consistent with the manually calculated ones. Accordingly, the accuracy and reliability of the algorithm is verified. The whole system is efficient, convenient and easy to operate, and it can meet the actual needs of MRI quality inspection.


Assuntos
Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética/normas , Algoritmos , Reprodutibilidade dos Testes
8.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 36(4): 677-683, 2019 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-31441271

RESUMO

With the development of image-guided surgery and radiotherapy, the demand for medical image registration is stronger and the challenge is greater. In recent years, deep learning, especially deep convolution neural networks, has made excellent achievements in medical image processing, and its research in registration has developed rapidly. In this paper, the research progress of medical image registration based on deep learning at home and abroad is reviewed according to the category of technical methods, which include similarity measurement with an iterative optimization strategy, direct estimation of transform parameters, etc. Then, the challenge of deep learning in medical image registration is analyzed, and the possible solutions and open research are proposed.


Assuntos
Aprendizado Profundo , Diagnóstico por Imagem , Redes Neurais (Computação) , Processamento de Imagem Assistida por Computador , Pesquisa
9.
Stud Health Technol Inform ; 264: 253-257, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31437924

RESUMO

During the acquisition on a low-dose radiation computed tomography (CT) scan, images are usually marked by heavy noise and undesired artifacts, which dramatically reduce its applicability in the image processing workflow. A noise reduction and detail preservation filter based on mathematical morphology is presented in this paper. The filter is geared to allow control of an opening operator followed by a systematic contrast limited adaptive histogram equalization (CLAHE) in conjunction with a reconstruction by dilation in last stage. A quantitative metric built on peak signal-to-noise ratio (PSNR), structural similarity (SSIM), and mean-squared error (MSE) were applied to check noise reduction, detail preservation, and performance. The results obtained by the proposed filter were compared with those obtained in the literature, showing very good results: compared with the best-tested filter, the filter had a gain of 7.91% on PSNR, 7.57% on SSIM and 37.8% on MSE.


Assuntos
Processamento de Imagem Assistida por Computador , Tomografia Computadorizada por Raios X , Algoritmos , Artefatos , Imagens de Fantasmas , Doses de Radiação , Razão Sinal-Ruído
10.
Stud Health Technol Inform ; 264: 1516-1517, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438209

RESUMO

Scientific challenges based on benchmark data enable the comparison and evaluation of different algorithms and take place regularly in scientific disciplines like medical image processing, text mining or genetics. The idea of a challenge is rarely applied within the eHealth community. Mappathon is a metadata mapping challenge that asks for methods to find corresponding data elements within similar datasets and to correlate data elements among each other.


Assuntos
Metadados , Telemedicina , Algoritmos , Mineração de Dados , Processamento de Imagem Assistida por Computador
11.
Stud Health Technol Inform ; 264: 1639-1640, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438269

RESUMO

A web-based tool is described to store images of ulcers and measure ulcer size automatically. The web tool enables doctors and caregivers to upload images from any device. The ulcer size is automatically extracted using image processing algorithms.


Assuntos
Processamento de Imagem Assistida por Computador , Algoritmos , Humanos , Ferimentos e Lesões
12.
Niger J Clin Pract ; 22(8): 1091-1098, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31417052

RESUMO

Aims: Our aim was to compare three different voxel sizes of CBCT images for the determination of residual filling material volume in root canals when compared with micro CT. Material and Methods: Forty-two root canals of 14 extracted human maxillary molar teeth were retreated by using ProFile® instruments. Images were obtained after retreatment by using ProMax 3D Max CBCT at 3 different voxel sizes (1) High resolution (0.1 mm); (2) High definition (0.15 mm); and (3) Normal resolution (0.2 mm). Two observers measured volumes of residual filling materials in exported CBCT images by means of 3D Doctor Software. Micro CT measurements were served as gold standard. Mann-Whitney U test and Wilcoxon Test were used for the comparison of CBCT and micro CT measurements. Statistical significance was set at P < 0.05. Results: No statistically differences were found between the two observers for all measurements (P > 0.05). There were no significant differences among different CBCT voxel sizes used (0.1 mm, 0.15 mm, and 0.2 mm) (P > 0.05). The Spearman correlation coefficients between CBCT at different voxel sizes significantly highly correlated with micro CT measurements for each observer (P < 0.05). Furthermore, no significant differences were found between the measurements obtained by the two observers in consideration to root canal location (P > 0.05). Conclusion: CBCT images may provide useful information in the volumetric assessment of the amount of residual filling material in root canals for retreatment procedures.


Assuntos
Cavidade Pulpar/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Dente Molar/cirurgia , Retratamento , Materiais Restauradores do Canal Radicular/química , Obturação do Canal Radicular/métodos , Tratamento do Canal Radicular/métodos , Tomografia Computadorizada de Feixe Cônico Espiral/métodos , Materiais Dentários , Humanos , Processamento de Imagem Assistida por Computador/métodos , Materiais Restauradores do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Microtomografia por Raio-X/métodos
13.
Am J Orthod Dentofacial Orthop ; 156(1): 44-52, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31256835

RESUMO

INTRODUCTION: The objective of this study was to investigate the location, orientation and root development of maxillary lateral incisors in patients with palatally impacted central incisors. Comparison was made between the lateral incisor on the affected side and that on the normally erupted side. METHODS: Cone-beam computed tomographic images from 20 patients (10 boys, 10 girls, mean age (9.01 ± 1.52 years old) with unilateral palatally impacted maxillary central incisors were imported into Dolphin imaging software 11.8 for 3-dimensional reconstruction and reorientation. Software measurement tools were used to measure the root length, crown distance, angle to palatal plane, distance to midline, and angle to midsagittal plane of the maxillary lateral incisors on both the impacted and unaffected sides. RESULTS: The Wilcoxon signed rank test indicated that lateral incisors on the impacted side were more proclined, at a mean angle difference of 29.47° in the sagittal plane (P < 0.001). The mean length of the roots of the lateral incisors was 1.21 mm shorter (P < 0.05) on the affected side compared with the normal side, and the lateral incisor crowns on the impacted side were located at an average of 4.57 mm closer to the palatal plane than on the normally erupted side (P < 0.001). The angle of long axis of the lateral incisors on the affected side had a greater angulation to the midsagittal plane compared with the unaffected side, with a mean difference of 30.27° (P < 0.001). CONCLUSIONS: Maxillary lateral incisors adjacent to palatally impacted maxillary central incisors side had abnormal root development and demonstrated angulation and position change compared with those adjacent to normally erupted central incisors.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Incisivo/anormalidades , Incisivo/anatomia & histologia , Maxila/anatomia & histologia , Palato/anatomia & histologia , Dente Impactado/diagnóstico por imagem , Criança , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imagem Tridimensional , Incisivo/diagnóstico por imagem , Masculino , Maxila/diagnóstico por imagem , Palato/diagnóstico por imagem , Estudos Retrospectivos , Coroa do Dente/anatomia & histologia , Erupção Dentária , Raiz Dentária/anormalidades , Raiz Dentária/anatomia & histologia , Raiz Dentária/diagnóstico por imagem
14.
Am J Orthod Dentofacial Orthop ; 156(1): 53-60, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31256838

RESUMO

INTRODUCTION: Pharyngeal airway space (PAS) assessment has been used in the past for a better understanding of orthodontic and surgical outcomes; however, this analysis could be unreliable. Our objective was to evaluate possible changes in the PAS reading in the same patient from their consecutive cone-beam computed tomography (CBCT) scans. METHODS: We evaluated a total of 27 patients' CBCT scans obtained at 2 time points with the use of a standardized acquisition protocol. The mean age at T0 was 31 years (range 17-62 years) and the follow-up records (T1) were taken after 4-6 months. Dolphin Imaging software was used to measure the volumes of the nasopharynx, oropharynx, and hypopharynx. We also evaluated the craniocervical position with the use of a lateral cephalogram. RESULTS: The variables exhibited high intraclass correlation coefficients (ICCs) when measuring the same CBCT scan twice (T0 and T0). However, The ICC between the measurements performed on the first and second CBCT scans (T0 and T1) showed that the only variable with high reproducibility between the 2 scans was cranial base, with an ICC >0.97. Average differences of 682.1 mm3, 2255.3 mm3, and 517.4 mm3 were found for the nasopharynx, oropharynx, and hypopharynx, respectively. Regarding the cephalometric angles, average differences between T0 and T1 scans were 0.6°, 2.7°, and 0.4° for OPT.CVT, OPT.SN, and cranial base, respectively. CONCLUSIONS: Different CBCT exams with equal scanning and patient positioning protocols can result in different 3D PAS readings. A more careful interpretation of CBCT volumetric data to achieve adequate conclusions of the clinical outcomes is necessary.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Tomografia Computadorizada de Feixe Cônico/normas , Posicionamento do Paciente/métodos , Posicionamento do Paciente/normas , Faringe/anatomia & histologia , Faringe/diagnóstico por imagem , Adolescente , Adulto , Cefalometria/métodos , Feminino , Seguimentos , Humanos , Hipofaringe/anatomia & histologia , Hipofaringe/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imagem Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Nasofaringe/anatomia & histologia , Nasofaringe/diagnóstico por imagem , Variações Dependentes do Observador , Orofaringe/anatomia & histologia , Orofaringe/diagnóstico por imagem , Procedimentos Cirúrgicos Ortognáticos , Valores de Referência , Reprodutibilidade dos Testes , Software , Adulto Jovem
15.
Environ Monit Assess ; 191(8): 481, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273539

RESUMO

This study presents a new fusion method namely supervised cross-fusion method to improve the capability of fused thermal, radar, and optical images for classification. The proposed cross-fusion method is a combination of pixel-based and supervised feature-based fusion of thermal, radar, and optical data. The pixel-based fusion was applied to fuse optical data of Sentinel-2 and Landsat 8. According to correlation coefficient (CR) and signal to noise ratio (SNR), among the used pixel-based fusion methods, wavelet obtained the best results for fusion. Considering spectral and spatial information preservation, CR of the wavelet method is 0.97 and 0.96, respectively. The supervised feature-based fusion method is a fusion of best output of pixel-based fusion level, land surface temperature (LST) data, and Sentinel-1 radar image using a supervised approach. The supervised approach is a supervised feature selection and learning of the inputs based on linear discriminant analysis and sparse regularization (LDASR) algorithm. In the present study, the non-negative matrix factorization (NMF) was utilized for feature extraction. A comparison of the obtained results with state of the art fusion method indicated a higher accuracy of our proposed method of classification. The rotation forest (RoF) classification results improvement was 25% and the support vector machine (SVM) results improvement was 31%. The results showed that the proposed method is well classified and separated four main classes of settlements, barren land, river, river bank, and even the bridges over the river. Also, a number of unclassified pixels by SVM are very low compared to other classification methods and can be neglected. The study results showed that LST calculated using thermal data has had positive effects on improving the classification results. By comparing the results of supervised cross-fusion without using LST data to the proposed method results, SVM and RoF classifiers showed 38% and 7% of classification improvement, respectively.


Assuntos
Monitoramento Ambiental/métodos , Processamento de Imagem Assistida por Computador/métodos , Algoritmos , Irã (Geográfico) , Radar , Rios , Máquina de Vetores de Suporte , Temperatura Ambiente
16.
Adv Exp Med Biol ; 1156: 85-96, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31338779

RESUMO

An atlas is generally defined as a bound collection of tables, charts or illustrations describing a phenomenon. In an anatomical atlas for example, a collection of representative illustrations and text describes anatomy for the purpose of communicating anatomical knowledge. The atlas serves as reference frame for comparing and integrating data from different sources by spatially or semantically relating collections of drawings, imaging data, and/or text. In the field of medical image processing, atlas information is often constructed from a collection of regions of interest, which are based on medical images that are annotated by domain experts. Such an atlas may be employed, for example, for automatic segmentation of medical imaging data. The combination of interactive visualization techniques with atlas information opens up new possibilities for content creation, curation, and navigation in virtual atlases. With interactive visualization of atlas information, students are able to inspect and explore anatomical atlases in ways that were not possible with the traditional method of presenting anatomical atlases in book format, such as viewing the illustrations from other viewpoints. With advanced interaction techniques, it becomes possible to query the data that forms the basis for the atlas, thus empowering researchers to access a wealth of information in new ways. So far, atlas-based visualization has been employed mainly for medical education, as well as biological research. In this survey, we provide an overview of current digital biomedical atlas tasks and applications and summarize relevant visualization techniques. We discuss recent approaches for providing next-generation visual interfaces to navigate atlas data that go beyond common text-based search and hierarchical lists. Finally, we reflect on open challenges and opportunities for the next steps in interactive atlas visualization.


Assuntos
Anatomia , Diagnóstico por Imagem , Processamento de Imagem Assistida por Computador , Anatomia/educação , Anatomia/métodos , Anatomia/tendências , Humanos
17.
Stud Health Technol Inform ; 262: 312-315, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31349330

RESUMO

Identifying imaging biomarkers (IBs) of stroke remains a priority in neurodiagnostics. There is a number of different methods for image analysis and learning rules applicable in this field, but all of them require large arrays of DICOM images and clinical data. In order to amass such dataset,we havedesigneda platform for systematic collection of clinical data and medical images in different modalities. The platform provides easy-to-use tools to create formalized radiology reports, contour and tag the regions of interest (ROIs) on the DICOM images, and extract radiomics data. Subsequent analysis of the obtained data will allow identifying the most relevant IBs that predict clinical outcome and possible complications. The results of the analysis will be used to develop predictive algorithms for stroke diagnostics.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Acidente Vascular Cerebral , Biomarcadores , Coleta de Dados , Humanos , Software , Acidente Vascular Cerebral/diagnóstico por imagem
18.
Food Chem ; 298: 125096, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31272051

RESUMO

The aim of this paper is to test different models for predicting furan content in a dough system, based on partial least squares regression using colour images. Starch dough systems were fried at five temperatures between 150 and 190 °C and for 5, 7, 9, 11 and 13 min. The furan content was quantified using gas chromatography/mass spectrometry, while the corresponding images were simultaneously obtained and processed in order to extract 2914 features. Good furan content predictions were obtained using computer vision image chromatic features using correlation coefficient of prediction (Rp = 0.86). However, the best prediction correlation was obtained using the image textural features (Rp = 0.93), when the number of features was reduced to 10 by algorithms applications. These results suggest that furan content in fried dough systems can be predicted using features of computer vision images.


Assuntos
Pão , Análise de Alimentos/métodos , Indústria de Processamento de Alimentos/métodos , Furanos/análise , Processamento de Imagem Assistida por Computador/métodos , Algoritmos , Cor , Culinária , Qualidade dos Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Análise dos Mínimos Quadrados , Amido , Triticum
19.
Environ Monit Assess ; 191(8): 491, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31297617

RESUMO

Leaf segmentation is significantly important in assisting ecologists to automatically detect symptoms of disease and other stressors affecting trees. This paper employs state-of-the-art techniques in image processing to introduce an accurate framework for segmenting leaves and diseased leaf spots from images. The proposed framework integrates an appearance model that visually represents the current input image with the color prior information generated from RGB color images that were formerly saved in our database. Our framework consists of four main steps: (1) Enhancing the accuracy of the segmentation at minimum time by making use of contrast changes to automatically identify the region of interest (ROI) of the entire leaf, where the pixel-wise intensity relations are described by an electric field energy model. (2) Modeling the visual appearance of the input image using a linear combination of discrete Gaussians (LCDG) to predict the marginal probability distributions of the grayscale ROI main three classes. (3) Calculating the pixel-wise probabilities of these three classes for the color ROI based on the color prior information of database images that are segmented manually, where the current and prior pixel-wise probabilities are used to find the initial labels. (4) Refining the labels with the generalized Gauss-Markov random field model (GGMRF), which maintains the continuity. The proposed segmentation approach was applied to the leaves of mangrove trees in Abu Dhabi in the United Arab Emirates. Experimental validation showed high accuracy, with a Dice similarity coefficient 90% for distinguishing leaf spot from healthy leaf area.


Assuntos
Monitoramento Ambiental/métodos , Processamento de Imagem Assistida por Computador/métodos , Doenças das Plantas , Folhas de Planta/química , Árvores/química , Algoritmos , Cor , Humanos , Distribuição Normal , Probabilidade , Sensibilidade e Especificidade , Emirados Árabes Unidos
20.
Environ Monit Assess ; 191(8): 495, 2019 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-31302796

RESUMO

Benefiting from current unmanned air vehicle (UAV) and remote sensing techniques, the present study aims to estimate tree count (TC), tree height (TH), and tree crown cover area (TCCA) in a young Calabrian pine stand via canopy height model (CHM). Overlay images obtained using Quadcopter were used to generate two spatial three-dimensional (3D) cloud points in two different qualities. Point clouds were processed using R program in order to produce tree data using CHM. The sensitivity of CHM-based tree data was revealed using 318 tree measurements in 32 different sampling units. Estimation and measurement values were classified based on their structure from motion (SfM) quality and cover classes, and the statistical relationships among them were analyzed. Without any classification, R2 was calculated for TC, THMean, and TCCATotal estimations and field measurements. R2 values were calculated as 0.865, 0.778, and 0.869, respectively, for SfMHighest CHM, while they were calculated as 0.863, 0.736, and 0.843, respectively, for SfMMedium CHM. In addition, sensitivity and performance ranking in different groups were determined based on root mean square error (RMSE) and mean absolute percentage error (MAPE) values. A significant difference was observed among groups in terms of quality and cover for TH, while no significant differences were observed for TCCA. Therefore, it is possible to estimate the properties of SfM CHM-based young coniferous stand. It was understood that tree density, crown shape, and branching influenced the accuracy of the present study. The developed UAV (Drone)-SfM is a promising technique for further small-scale forestry studies.


Assuntos
Monitoramento Ambiental/métodos , Agricultura Florestal/métodos , Florestas , Pinus/crescimento & desenvolvimento , Tecnologia de Sensoriamento Remoto , Árvores/crescimento & desenvolvimento , Algoritmos , Processamento de Imagem Assistida por Computador , Análise Espacial , Turquia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA