RESUMO
High positive margin rates in oncologic breast-conserving surgery are a pressing clinical problem. Volumetric X-ray scanning is emerging as a powerful ex vivo specimen imaging technique for analyzing resection margins, but X-rays lack contrast between non-malignant and malignant fibrous tissues. In this study, combined micro-CT and wide-field optical image radiomics were developed to classify malignancy of breast cancer tissues, demonstrating that X-ray/optical radiomics improve malignancy classification. Ninety-two standardized features were extracted from co-registered micro-CT and optical spatial frequency domain imaging samples extracted from 54 breast tumors exhibiting seven tissue subtypes confirmed by microscopic histological analysis. Multimodal feature sets improved classification performance versus micro-CT alone when adipose samples were included (AUC = 0.88 vs. 0.90; p-value = 3.65e-11) and excluded, focusing the classification task on exclusively non-malignant fibrous versus malignant tissues (AUC = 0.78 vs. 0.85; p-value = 9.33e-14). Extending the radiomics approach to high-dimensional optical data-termed "optomics" in this study-offers a promising optical image analysis technique for cancer detection. Radiomic feature data and classification source code are publicly available.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Mastectomia Segmentar/métodos , Imagem Óptica/métodos , Microtomografia por Raio-X/métodos , Tecido Adiposo/diagnóstico por imagem , Neoplasias da Mama/classificação , Feminino , Humanos , Técnicas In Vitro , Margens de Excisão , Imagem Multimodal/instrumentação , Imagem Multimodal/métodos , Imagem Multimodal/estatística & dados numéricos , Imagem Óptica/instrumentação , Imagem Óptica/estatística & dados numéricos , Fenômenos Ópticos , Processos Estocásticos , Microtomografia por Raio-X/instrumentação , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
Although many ureteral stents are commercially available, the actuality of encrustation is yet to be elucidated in humans. This study compared the Tria Ureteral Stent with PercuShield and the Polaris Ultra Ureteral Stent with HydroPlus Coating for short-term encrustation formation. Eighty-four patients, who required ureteral stent placement after ureteroscopy, were randomized into two stent groups. After stent removal on postoperative day 14, the encrustation volume on the stent surface was measured by micro-computed tomography. The primary outcome was the inner luminal encrustation volume. Secondary outcomes were encrustation volume on the outer or total surfaces and occurrence of adverse events. Clinical factors related to encrustation were also assessed as a post-hoc analysis. Finally, of the 82 patients analyzed, 75 (91.5%) had encrustation in the inner lumen of the stent. The difference in median inner encrustation volume between the Tria and Polaris Ultra stents was comparable (0.56 vs. 0.37 mm3, P = 0.183). There was no difference observed in the encrustation volume on the outer/total surfaces and stent-related adverse events. In both ureteral stents, the shaft body showed significant inner luminal encrustation compared to the proximal or distal loop (all, P < 0.05). Dyslipidemia (P = 0.027), elevated urine pH (P = 0.046), and crystalluria (P = 0.010) were associated with encrustation formation. The Tria and Polaris Ultra stents had similar efficacy for preventing encrustation in the short-term. Further studies are required to compare their long-term patency.
Assuntos
Stents/efeitos adversos , Ureteroscopia/instrumentação , Urolitíase/cirurgia , Idoso , Remoção de Dispositivo/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Stents/estatística & dados numéricos , Ureter/cirurgia , Ureteroscopia/efeitos adversos , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
Reproducible and unbiased methods to quantify alveolar structure are important for research on many lung diseases. However, manually estimating alveolar structure through stereology is time consuming and inter-observer variability is high. The objective of this work was to develop and validate a fast, reproducible and accurate (semi-)automatic alternative. A FIJI-macro was designed that automatically segments lung images to binary masks, and counts the number of test points falling on tissue and the number of intersections of the air-tissue interface with a set of test lines. Manual selection remains necessary for the recognition of non-parenchymal tissue and alveolar exudates. Volume density of alveolar septa ([Formula: see text]) and mean linear intercept of the airspaces (Lm) as measured by the macro were compared to theoretical values for 11 artificial test images and to manually counted values for 17 lungs slides using linear regression and Bland-Altman plots. Inter-observer agreement between 3 observers, measuring 8 lungs both manually and automatically, was assessed using intraclass correlation coefficients (ICC). [Formula: see text] and Lm measured by the macro closely approached theoretical values for artificial test images (R2 of 0.9750 and 0.9573 and bias of 0.34% and 8.7%). The macro data in lungs were slightly higher for [Formula: see text] and slightly lower for Lm in comparison to manually counted values (R2 of 0.8262 and 0.8288 and bias of -6.0% and 12.1%). Visually, semi-automatic segmentation was accurate. Most importantly, manually counted [Formula: see text] and Lm had only moderate to good inter-observer agreement (ICC 0.859 and 0.643), but agreements were excellent for semi-automatically counted values (ICC 0.956 and 0.900). This semi-automatic method provides accurate and highly reproducible alveolar morphometry results. Future efforts should focus on refining methods for automatic detection of non-parenchymal tissue or exudates, and for assessment of lung structure on 3D reconstructions of lungs scanned with microCT.
Assuntos
Displasia Broncopulmonar/patologia , Interpretação de Imagem Assistida por Computador/métodos , Alvéolos Pulmonares/patologia , Animais , Displasia Broncopulmonar/diagnóstico por imagem , Modelos Animais de Doenças , Feminino , Técnicas Histológicas/estatística & dados numéricos , Variações Dependentes do Observador , Gravidez , Alvéolos Pulmonares/diagnóstico por imagem , Coelhos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
Throughout the process of aging, dynamic changes of bone material, micro- and macro-architecture result in a loss of strength and therefore in an increased likelihood of fragility fractures. To date, precise contributions of age-related changes in bone (re)modeling and (de)mineralization dynamics to this fragility increase are not completely understood. Here, we present an image-based deep learning approach to quantitatively describe the effects of short-term aging and adaptive response to cyclic loading applied to proximal mouse tibiae and fibulae. Our approach allowed us to perform an end-to-end age prediction based on µCT imaging to determine the dynamic biological process of aging during a two week period, therefore permitting short-term bone aging analysis with 95% accuracy in predicting time points. In a second application, our deep learning analysis reveals that two weeks of in vivo mechanical loading are associated with an underlying rejuvenating effect of 5 days. Additionally, by quantitatively analyzing the learning process, we could, for the first time, identify the localization of the age-relevant encoded information and demonstrate 89% load-induced similarity of these locations in the loaded tibia with younger control bones. These data therefore suggest that our method enables identifying a general prognostic phenotype of a certain skeletal age as well as a temporal and localized loading-treatment effect on this apparent skeletal age for the studied mouse tibia and fibula. Future translational applications of this method may provide an improved decision-support method for osteoporosis treatment at relatively low cost. STATEMENT OF SIGNIFICANCE: Bone is a highly complex and dynamic structure that undergoes changes during the course of aging as well as in response to external stimuli, such as loading. Automatic assessment of "age" and "state" of the bone may lead to early prognosis of deceases such as osteoporosis and enables evaluating the effects of certain treatments. Here, we present an artificial intelligence-based method capable of automatically predicting the skeletal age from µCT images with 95% accuracy. Additionally, we utilize it to demonstrate the rejuvenation effects of in-vivo loading treatment on bones. We further, for the first time, break down aging-related local changes in bone by quantitatively analyzing "what the age assessment model has learned" and use this information to investigate the structural details of rejuvenation process.
Assuntos
Envelhecimento/fisiologia , Aprendizado Profundo , Fíbula/metabolismo , Rejuvenescimento/fisiologia , Tíbia/metabolismo , Suporte de Carga/fisiologia , Adaptação Fisiológica/fisiologia , Animais , Feminino , Camundongos Endogâmicos C57BL , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
3D imaging approaches based on X-ray microcomputed tomography (microCT) have become increasingly accessible with advancements in methods, instruments and expertise. The synergy of material and life sciences has impacted biomedical research by proposing new tools for investigation. However, data sharing remains challenging as microCT files are usually in the range of gigabytes and require specific and expensive software for rendering and interpretation. Here, we provide an advanced method for visualisation and interpretation of microCT data with small file formats, readable on all operating systems, using freely available Portable Document Format (PDF) software. Our method is based on the conversion of volumetric data into interactive 3D PDF, allowing rotation, movement, magnification and setting modifications of objects, thus providing an intuitive approach to analyse structures in a 3D context. We describe the complete pipeline from data acquisition, data processing and compression, to 3D PDF formatting on an example of craniofacial anatomical morphology in the mouse embryo. Our procedure is widely applicable in biological research and can be used as a framework to analyse volumetric data from any research field relying on 3D rendering and CT-biomedical imaging.
Assuntos
Imageamento Tridimensional/estatística & dados numéricos , Software , Microtomografia por Raio-X/estatística & dados numéricos , Animais , Compressão de Dados/estatística & dados numéricos , Processamento Eletrônico de Dados , Ossos Faciais/anatomia & histologia , Ossos Faciais/embriologia , Disseminação de Informação/métodos , Camundongos , Modelos Anatômicos , Interpretação de Imagem Radiográfica Assistida por Computador , Crânio/anatomia & histologia , Crânio/embriologiaRESUMO
BACKGROUND AND OBJECTIVE: Optimal development of placental vasculature is critical for fetal growth and health outcomes. Many studies characterizing the vascular structure of the fetal side of the placenta have utilized a range of two-dimensional and three-dimensional (3D) imaging techniques including X-ray micro-computed tomography (micro-CT) following perfusion of the vasculature with a radio-opaque compound. The CT approach has been used to study feto-placental vasculature in rodents and humans. Its inherent advantage is that it reveals the 3D structure in high resolution without destroying the sample. This permits both multiple scanning of the sample and follow-up histological investigations in the same sample. Nevertheless, the applicability of the approach is hampered both by the challenging segmentation of the vasculature and a lack of straightforward methodology to quantitate the feto-placental vascular network. This paper addresses these challenges. METHODS: An end-to-end methodology is presented for automatically segmenting the vasculature; obtaining a Strahler-ordered rooted-tree representation and extracting quantitative features from its nodes, segments and branches (including volume, length, tortuosity and branching angles). The methodology is demonstrated for rat and mouse placentas at the end of gestation (day 22 and day 18, respectively), perfused with Microfil® and imaged using two different micro-CT scanners. RESULTS: The 3D visualizations of the resulting vascular trees clearly demonstrate differences between the branching complexity, tree span and tree depth of the mouse and rat placentas. The quantitative characterizations of these trees include not only the fundamental features that have been utilized in other studies of feto-placental vasculature but also several additional features. Boxplots of several of these-tortuosity, number of side branches, number of offspring per branch and branch volume-computed at each Strahler order are presented and interpreted. Differences and similarities between the mouse and rat casts are readily detected. CONCLUSION: The proposed end-to-end methodology, and the implementation presented using a combination of Amira and Matlab, offers researchers in the field of placental vasculature characterization a straightforward and objective approach for quantifying micro-CT vascular datasets.
Assuntos
Feto/irrigação sanguínea , Placenta/irrigação sanguínea , Circulação Placentária/fisiologia , Algoritmos , Animais , Feminino , Desenvolvimento Fetal , Feto/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Camundongos , Modelos Cardiovasculares , Placenta/diagnóstico por imagem , Placentação , Gravidez , Interpretação de Imagem Radiográfica Assistida por Computador/estatística & dados numéricos , Ratos , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
Cardiovascular diseases (CVDs) affect the myocardium and vasculature, inducing remodelling of the heart from cellular to whole organ level. To assess their impact at micro and macroscopic level, multi-resolution imaging techniques that provide high quality images without sample alteration and in 3D are necessary: requirements not fulfilled by most of current methods. In this paper, we take advantage of the non-destructive time-efficient 3D multiscale capabilities of synchrotron Propagation-based X-Ray Phase Contrast Imaging (PB-X-PCI) to study a wide range of cardiac tissue characteristics in one healthy and three different diseased rat models. With a dedicated image processing pipeline, PB-X-PCI images are analysed in order to show its capability to assess different cardiac tissue components at both macroscopic and microscopic levels. The presented technique evaluates in detail the overall cardiac morphology, myocyte aggregate orientation, vasculature changes, fibrosis formation and nearly single cell arrangement. Our results agree with conventional histology and literature. This study demonstrates that synchrotron PB-X-PCI, combined with image processing tools, is a powerful technique for multi-resolution structural investigation of the heart ex-vivo. Therefore, the proposed approach can improve the understanding of the multiscale remodelling processes occurring in CVDs, and the comprehensive and fast assessment of future interventional approaches.
Assuntos
Insuficiência Cardíaca/diagnóstico por imagem , Coração/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Imageamento Tridimensional/estatística & dados numéricos , Infarto do Miocárdio/diagnóstico por imagem , Microtomografia por Raio-X/estatística & dados numéricos , Agonistas Adrenérgicos beta/farmacologia , Animais , Vasos Coronários/cirurgia , Modelos Animais de Doenças , Coração/fisiopatologia , Insuficiência Cardíaca/induzido quimicamente , Insuficiência Cardíaca/fisiopatologia , Imageamento Tridimensional/métodos , Isoproterenol/farmacologia , Ligadura , Masculino , Infarto do Miocárdio/induzido quimicamente , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Ratos Wistar , Síncrotrons , Microtomografia por Raio-X/métodosRESUMO
The estimation of cortical thickness (Ct.Th) and porosity (Ct.Po) at the tibia using axial transmission ultrasound was successfully validated ex vivo against site-matched micro-computed tomography. The assessment of cortical parameters based on full-spectrum guided-wave analysis might improve the prediction of bone fractures in a cost-effective and radiation-free manner. PURPOSE: Cortical thickness (Ct.Th) and porosity (Ct.Po) are key parameters for the identification of patients with fragile bones. The main objective of this ex vivo study was to validate the measurement of Ct.Po and Ct.Th at the tibia using a non-ionizing, low-cost, and portable 500-kHz ultrasound axial transmission system. Additional ultrasonic velocities and site-matched reference parameters were included in the study to broaden the analysis. METHODS: Guided waves were successfully measured ex vivo in 17 human tibiae using a novel 500-kHz bi-directional axial transmission probe. Theoretical dispersion curves of a transverse isotropic free plate model with invariant matrix stiffness were fitted to the experimental dispersion curves in order to estimate Ct.Th and Ct.Po. In addition, the velocities of the first arriving signal (υFAS) and A0 mode (υA0) were measured. Reference Ct.Po, Ct.Th, and vBMD were obtained from site-matched micro-computed tomography. Scanning acoustic microscopy (SAM) provided the acoustic impedance of the axial cortical bone matrix. RESULTS: The best predictions of Ct.Po (R2 = 0.83, RMSE = 2.2%) and Ct.Th (R2 = 0.92, RMSE = 0.2 mm, one outlier excluded) were obtained from the plate model. The second best predictors of Ct.Po and Ct.Th were vBMD (R2 = 0.77, RMSE = 2.6%) and υA0 (R2 = 0.28, RMSE = 0.67 mm), respectively. CONCLUSIONS: Ct.Th and Ct.Po were accurately predicted at the human tibia ex vivo using a transverse isotropic free plate model with invariant matrix stiffness. The model-based predictions were not further enhanced when we accounted for variations in axial tissue stiffness as reflected by the acoustic impedance from SAM.
Assuntos
Doenças Ósseas/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Tíbia/diagnóstico por imagem , Ultrassonografia/estatística & dados numéricos , Microtomografia por Raio-X/estatística & dados numéricos , Testes de Impedância Acústica , Densidade Óssea , Osso Cortical/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador/métodos , Porosidade , Valor Preditivo dos Testes , Rádio (Anatomia)/diagnóstico por imagem , Tíbia/fisiopatologia , Ultrassonografia/métodos , Microtomografia por Raio-X/métodosRESUMO
Computerized microtomography is the gold standard examination for the evaluation of the three-dimensional bone structure. This experiment was developed to evaluate the structure and bone quality of Caiman yacare with metabolic bone disease using high resolution computerized microtomography (μCT). The animals were distributed into four groups: G1 - hyperphosphatemic diet with sun exposure deprivation (n=4), G2 - hyperphosphatemic diet with sun exposure (n=4), G3 - balanced diet with sun exposure deprivation (n=4), and G4 - balanced diet with exposure to sunlight (n=4). The parameters for the trabecular bone (Trabecular Number, Trabecular Thickness, Trabecular Separation, Bone Pattern Factor, Fractal Dimension, Euler Number, Structural Model Index, Degree of Anisotropy, Eigenvalues 1, 2 and 3, and Centroides X, Y and Z), and cortical bone (Number of Closed Pores, Volume of Closed Pores, Surface of Closed Pores, Closed Porosity, Volume of Open Pores, Open Porosity and Total Porosity). The overall results showed that the structure and bone quality of group G3 and G4 were better than those of groups G1 and G2, and that the diet factor influenced more than the sun exposure factor. The computerized microtomography allowed to evaluate the quality of the cortical and trabecular bones of the Pantanal alligator tibia with osteometabolic disease. The diet and sun exposure factors influenced individually the results of the μCT parameters between the groups, demonstrating the functional and structural complexity. Thus, these parameters can contribute to the interpretation of the mechanical behavior of bones and correlate them with the risk of lesions and fractures associated with osteometabolic diseases.(AU)
Microtomografia computadorizada é o exame padrão-ouro para a avaliação da estrutura tridimensional do osso. Este estudo experimental foi desenvolvido para avaliar a estrutura e a qualidade óssea de jacarés-do-pantanal (Caiman yacare) com doença óssea metabólica utilizando a microtomografia computadorizada (μCT) de Alta Resolução. Os animais foram distribuídos em quatro grupos, G1 - dieta hiperfosfatêmica com privação de luz solar (n=4), G2 - dieta hiperfosfatêmica com exposição à luz solar (n=4), G3 - dieta balanceada com privação de luz solar (n=4) e G4 - dieta balanceada com exposição à luz solar (n=4). Avaliaram-se os parâmetros para o osso trabecular (Número de Trabéculas, Espessura Trabecular, Separação Trabecular, Fator do Padrão Ósseo, Dimensão Fractal, Número de Euler, Índice do Modelo Estrutural, Grau de Anisotropia, Autovalores 1, 2 e 3 e Centroides X, Y e Z) e osso cortical (Número de Poros Fechados, Volume dos Poros Fechados, Superfície de Poros Fechados, Porosidade Fechada, Volume de Poros Abertos, Porosidade Aberta e Porosidade Total). Os resultados gerais evidenciaram que a estrutura e a qualidade óssea dos grupos G3 e G4 foram superiores aos dos grupos G1 e G2, sendo que o fator dieta influenciou mais do que o fator exposição solar. A Microtomografia Computadorizada permitiu avaliar a qualidade dos ossos cortical e trabecular da tíbia de jacarés do pantanal com doença osteometabólica. Os fatores dieta e exposição solar influenciaram individualmente no resultado dos parâmetros do μCT entre os grupos, demonstrando a complexidade funcional e estrutural. Assim, esses parâmetros podem contribuir na interpretação do comportamento mecânico dos ossos e correlacioná-los com o risco de lesões e fraturas associadas às doenças osteometabólicas.(AU)
Assuntos
Animais , Doenças Ósseas/classificação , Jacarés e Crocodilos/anormalidades , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
Skeletonization offers a compact representation of an object while preserving important topological and geometrical features. Literature on skeletonization of binary objects is quite mature. However, challenges involved with skeletonization of fuzzy objects are mostly unanswered. This paper presents a new theory and algorithm of skeletonization for fuzzy objects, evaluates its performance, and demonstrates its applications. A formulation of fuzzy grassfire propagation is introduced; its relationships with fuzzy distance functions, level sets, and geodesics are discussed; and several new theoretical results are presented in the continuous space. A notion of collision-impact of fire-fronts at skeletal points is introduced, and its role in filtering noisy skeletal points is demonstrated. A fuzzy object skeletonization algorithm is developed using new notions of surface- and curve-skeletal voxels, digital collision-impact, filtering of noisy skeletal voxels, and continuity of skeletal surfaces. A skeletal noise pruning algorithm is presented using branch-level significance. Accuracy and robustness of the new algorithm are examined on computer-generated phantoms and micro- and conventional CT imaging of trabecular bone specimens. An application of fuzzy object skeletonization to compute structure-width at a low image resolution is demonstrated, and its ability to predict bone strength is examined. Finally, the performance of the new fuzzy object skeletonization algorithm is compared with two binary object skeletonization methods.
Assuntos
Algoritmos , Gráficos por Computador/estatística & dados numéricos , Lógica Fuzzy , Animais , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/fisiologia , Simulação por Computador , Humanos , Modelos Anatômicos , Modelos Estatísticos , Imagens de Fantasmas/estatística & dados numéricos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
Micro computed tomography (micro-CT) has already been proposed as a useful technique for the qualitative analysis of false starts (FS) produced on human bones, although the reliability and the error rate of this technique have not been tested yet, neither for qualitative nor for quantitative assessments. The aim of the present study was to test the morphological agreement, accuracy, precision and inter-rater reliability of micro-CT analysis of FS on bones. The morphological agreement was assessed through the degree of concordance among the 3 independent blind raters in the identification of the shape of 24 FS manually produced on bones by 3 different saws (8 FS for each saw). The accuracy was calculated through the percentage of error in the automatic and manual measurement of the diameter of a reference object. The precision was calculated as CV% of multiple measurements performed by 3 independent blind raters on the reference object and one bone sample acquired 20 times. The inter-rater reliability was assessed as intraclass correlation coefficient (ICC) among measurements performed by 3 independent blind raters, assessing 24 FS produced using 3 different saws. The results demonstrated that both qualitative and quantitative analysis were reproducible and robust. Micro-CT analysis showed a 100% morphological agreement, a high level of accuracy (percentage errorâ¯<â¯0,5%), precision (CV%â¯<â¯5%) and inter-rater reliability (ICCâ¯>â¯0.995), when FS were analyzed by forensic pathologists and/or radiologists with adequate expertise. Obviously, further validation studies are needed, including a higher number of samples produced by a wider variety of saws and multiple operators.
Assuntos
Osso e Ossos , Variações Dependentes do Observador , Microtomografia por Raio-X/normas , Estudos de Avaliação como Assunto , Antropologia Forense , Humanos , Reprodutibilidade dos Testes , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
INTRODUCTION: The purpose of this study was to compare root and root canal width measurements between digital intraoral radiography (IOR) and micro-computed tomography (µCT). The accuracy of IOR measurements of canine mandibular molars was scrutinized to assess feasibility of developing a model to estimate animal age based on dentinal thickness. MATERIALS AND METHODS: Thirty-nine canine mandibular first molars were imaged using µCT and IOR. For each tooth, the root and root canal width of the mesial and distal roots were measured by a single observer at 3 marked sites on µCT and IOR. Two different software programs were used to measure the radiographs. The radiograph measurements were compared to each other and to the µCT measurements. The µCT images were considered the anatomic reference standard for structural representation. RESULTS: The data collected demonstrated IOR bias and variability throughout all measurement sites, with some sites being more affected than others. Neither IOR system produced unbiased measurements that closely reflected the µCT measurements consistently. The overall lack of agreement between measurements demonstrated the difficulties in developing a standardized protocol for measuring root and root canal width for the first molar teeth in dogs. CONCLUSION: Developing a protocol to accurately measure and compare µCT and IOR measurements is challenging. Designing a measurement system that would allow for universal application to age dogs would require continued research utilizing a standardized approach to overcome the limitations identified in this article.
Assuntos
Determinação da Idade pelos Dentes/veterinária , Cavidade Pulpar/diagnóstico por imagem , Cães , Dente Molar/diagnóstico por imagem , Radiografia Dentária Digital/veterinária , Raiz Dentária/diagnóstico por imagem , Microtomografia por Raio-X/veterinária , Determinação da Idade pelos Dentes/métodos , Animais , Dentina/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Modelos Teóricos , Radiografia Dentária Digital/métodos , Radiografia Dentária Digital/estatística & dados numéricos , Reprodutibilidade dos Testes , Microtomografia por Raio-X/métodos , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
BACKGROUND: The aim of the study is to determine if bone quality evaluation of surgically obtained bone core specimens using a stereomicroscope is reliable for determining bone quality at implant recipient sites. METHODS: Bone quality was presurgically assessed in 122 edentulous ridges obtained from 62 patients using periapical radiographs and categorized according to the Lekholm and Zarb classification. During surgery, bone specimens were trephined, and bone types were immediately classified using a stereomicroscope. Microarchitectural characteristics of bone cores were evaluated after being scanned using microcomputed tomography (micro-CT). RESULTS: Bone types of implant sites categorized from radiography and stereomicroscope had statistically similar distribution but poor interrater agreement. Using micro-CT, maxillae and mandibles showed significant differences in microarchitectural characteristics of bone cores. Bone volume (BV), total volume (TV), and trabecular thickness (Tb.Th) increased, whereas bone surface density (BS/BV) and open porosity (Po.[Op]) decreased in mandibular bone cores compared with those in maxillary bone cores. Moreover, micro-CT values of BV/TV and Po.(Op) statistically correlated with bone types assessed by stereomicroscopy, particularly in mandibles (adjusted means of BV/TV of Type 2 to 4 versus Type 1 decreasing from -9.88%, -15.09%, -29.31%; those of Po.(Op) ranged from 9.77%, 15.06%, 29.52% in an upward trend). However, such correlations were not found in maxillae or when bone types were classified using periapical radiographs. CONCLUSIONS: Caution is needed when using presurgical periapical radiographs to predict bone quality at implant recipient sites. Surgically preserved bone core specimens, whenever obtainable, might offer additional information to accurately assess bone quality, particularly at mandibular implant sites.
Assuntos
Densidade Óssea/fisiologia , Tomografia Computadorizada de Feixe Cônico/métodos , Implantação Dentária Endóssea , Mandíbula/patologia , Maxila/patologia , Radiografia Dentária/métodos , Microtomografia por Raio-X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Implantes Dentários , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Arcada Edêntula/diagnóstico por imagem , Arcada Edêntula/patologia , Masculino , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Maxila/diagnóstico por imagem , Pessoa de Meia-Idade , Radiografia Dentária/estatística & dados numéricos , Cirurgia Assistida por Computador/métodos , Cirurgia Assistida por Computador/estatística & dados numéricos , Taiwan , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
BACKGROUND: Computational modeling of intracranial aneurysms provides insights into the influence of hemodynamics on aneurysm growth, rupture, and treatment outcome. Standard modeling of coiled aneurysms simplifies the complex geometry of the coil mass into a homogeneous porous medium that fills the aneurysmal sac. We compare hemodynamics of coiled aneurysms modeled from high-resolution imaging with those from the same aneurysms modeled following the standard technique, in an effort to characterize sources of error from the simplified model. MATERIALS: Physical models of two unruptured aneurysms were created using three-dimensional printing. The models were treated with coil embolization using the same coils as those used in actual patient treatment and then scanned by synchrotron X-ray microtomography to obtain high-resolution imaging of the coil mass. Computational modeling of each aneurysm was performed using patient-specific boundary conditions. The coils were modeled using the simplified porous medium or by incorporating the X-ray imaged coil surface, and the differences in hemodynamic variables were assessed. RESULTS: X-ray microtomographic imaging of coils and incorporation into computational models were successful for both aneurysms. Porous medium calculations of coiled aneurysm hemodynamics overestimated intra-aneurysmal flow, underestimated oscillatory shear index and viscous dissipation, and over- or underpredicted wall shear stress (WSS) and WSS gradient compared with X-ray-based coiled computational fluid dynamics models. CONCLUSIONS: Computational modeling of coiled intracranial aneurysms using the porous medium approach may inaccurately estimate key hemodynamic variables compared with models incorporating high-resolution synchrotron X-ray microtomographic imaging of complex aneurysm coil geometry.
Assuntos
Simulação por Computador , Hidrodinâmica , Aneurisma Intracraniano/diagnóstico por imagem , Impressão Tridimensional , Síncrotrons , Microtomografia por Raio-X/métodos , Prótese Vascular/estatística & dados numéricos , Simulação por Computador/estatística & dados numéricos , Procedimentos Endovasculares/métodos , Procedimentos Endovasculares/estatística & dados numéricos , Hemodinâmica/fisiologia , Humanos , Aneurisma Intracraniano/cirurgia , Aneurisma Intracraniano/terapia , Porosidade , Impressão Tridimensional/estatística & dados numéricos , Síncrotrons/estatística & dados numéricos , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
A new miniature species of banjo catfish of the genus Hoplomyzon is described from the Lake Maracaibo Basin in Venezuela. The new species is distinguished from all its congeners by the straight anterior margin of the mesethmoid (vs. a medial notch); a smooth and straight ventral surface of the premaxilla (vs. presence of bony knobs on the ventral surface of premaxilla); absence of teeth on dentary (vs. teeth present on dentary); configuration of ventral vertebral processes anterior to anal fin, which are composed of single processes anterior to anal-fin pterygiophore (vs. paired process); presence of several filamentous barbel-like structures on the ventral surface of head of adults (vs. small papillous structures in the ventral surface of head of adults); and 8 anal-fin rays (vs. 6 or 7). An extensive osteological description is made of the holotype using high-resolution x-ray computed microtomography (HRXCT).(AU)
Se describe una nueva especie miniatura de pez banjo perteneciente al género Hoplomyzon, proveniente de tributarios del Lago Maracaibo en Venezuela. La nueva especie se diferencia de sus congéneres por presentar el margen anterior del mesetmoide recto (vs. con una hendidura central); superficie ventral de la premaxila lisa y recta (vs. superficie ventral de la premaxila con protuberancias óseas); ausencia de dientes en el dentario (vs. dientes presentes); configuración de los procesos anteriores ventrales de la aleta anal, los que están compuestos de procesos simples anteriores al pterigióforo de la aleta anal (vs. procesos dobles); presencia de varias estructuras en forma de barbillas en la superficie ventral de la cabeza (vs. pequeñas estructuras en forma de papilas en la superficie ventral de la cabeza); y 8 radios en la aleta anal (vs. 6 o 7). Una extensiva descripción osteológica del holotipo fue realizada utilizando microtomografía computarizada de rayos X de alta resolución (HRCXCT).(AU)
Assuntos
Animais , Peixes-Gato/classificação , Microtomografia por Raio-X/estatística & dados numéricos , ClassificaçãoRESUMO
Artifacts induced by respiratory motion during routine diagnosis severely degrades the image quality. The increase of scanning speed plays an important role to avoid motion artifacts. Limited to the mechanical structure of conventional CT, the increase of gantry rotational speed is unsustainable and a more feasible way is to increase the number of X-ray sources and detectors like the dual-source CT. This paper focuses on high-speed scanning CT and proposes a novel ultrafast micro-CT (UMCT) system based on carbon nanotube (CNT). At each exposure position, all of the X-ray sources are fast activated by turns and the flat-panel detectors collect the corresponding projection data. Then, the gantry will be contrarotated 40° to prepare for the next exposure until the rotation covers full 360°. Because each exposure is very fast, the organ motions of in vivo human body can be greatly reduced. This paper introduces the UMCT system design, image reconstruction algorithm and experimental results. Simulation experiment was also carried out on UMCT system. The result validated the feasibility of the UMCT system.
Assuntos
Microtomografia por Raio-X/instrumentação , Algoritmos , Fenômenos Biofísicos , Simulação por Computador , Desenho de Equipamento , Estudos de Viabilidade , Humanos , Imageamento Tridimensional/métodos , Nanotubos de Carbono , Imagens de Fantasmas , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Microtomografia por Raio-X/métodos , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
OBJECTIVES: Proximal dental caries remains a prevalent disease with only modest detection rates by current diagnostic systems. Many new systems are available without controlled validation of diagnostic efficacy. The objective of this study was to evaluate the diagnostic efficacy of three potentially promising new imaging systems. METHODS: This study evaluated the caries detection efficacy of Schick 33 (Sirona Dental, Salzburg, Austria) intraoral digital detector images employing an advanced sharpening filter, Planmeca ProMax(®) (Planmeca Inc., Helsinki, Finland) extraoral "panoramic bitewing" images and Sirona Orthophos XG3D (Sirona Dental) CBCT images with advanced artefact reduction. Conventional photostimulable phosphor images served as the control modality. An ex vivo study design using extracted human teeth, ten expert observers and micro-CT ground truth was employed. RESULTS: Receiver operating characteristic analysis indicated similar diagnostic efficacy of all systems (ANOVA p > 0.05). The sensitivity of the Schick 33 images (0.48) was significantly lower than the other modalities (0.53-0.62). The specificity of the Planmeca images (0.86) was significantly lower than Schick 33 (0.96) and XG3D (0.97). The XG3D showed significantly better cavitation detection sensitivity (0.62) than the other modalities (0.48-0.57). CONCLUSIONS: The Schick 33 images demonstrated reduced caries sensitivity, whereas the Planmeca panoramic bitewing images demonstrated reduced specificity. XG3D with artefact reduction demonstrated elevated sensitivity and specificity for caries detection, improved depth accuracy and substantially improved cavitation detection. Care must be taken to recognize potential false-positive caries lesions with Planmeca panoramic bitewing images. Use of CBCT for caries detection must be carefully balanced with the presence of metal artefacts, time commitment, financial cost and radiation dose.
Assuntos
Cárie Dentária/diagnóstico por imagem , Imageamento Tridimensional/estatística & dados numéricos , Radiografia Dentária/estatística & dados numéricos , Artefatos , Tomografia Computadorizada de Feixe Cônico/estatística & dados numéricos , Humanos , Teste de Materiais , Curva ROC , Radiografia Interproximal/estatística & dados numéricos , Radiografia Dentária Digital/estatística & dados numéricos , Radiografia Panorâmica/estatística & dados numéricos , Sensibilidade e Especificidade , Tecnologia Odontológica/estatística & dados numéricos , Tecnologia Radiológica/estatística & dados numéricos , Ecrans Intensificadores para Raios X/estatística & dados numéricos , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
Optical molecular imaging is a promising technique and has been widely used in physiology, and pathology at cellular and molecular levels, which includes different modalities such as bioluminescence tomography, fluorescence molecular tomography and Cerenkov luminescence tomography. The inverse problem is ill-posed for the above modalities, which cause a nonunique solution. In this paper, we propose an effective reconstruction method based on the linearized Bregman iterative algorithm with sparse regularization (LBSR) for reconstruction. Considering the sparsity characteristics of the reconstructed sources, the sparsity can be regarded as a kind of a priori information and sparse regularization is incorporated, which can accurately locate the position of the source. The linearized Bregman iteration method is exploited to minimize the sparse regularization problem so as to further achieve fast and accurate reconstruction results. Experimental results in a numerical simulation and in vivo mouse demonstrate the effectiveness and potential of the proposed method.
Assuntos
Processamento de Imagem Assistida por Computador/métodos , Tomografia Óptica/estatística & dados numéricos , Algoritmos , Animais , Simulação por Computador , Humanos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Modelos Lineares , Camundongos , Camundongos Nus , Modelos Estatísticos , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
BACKGROUND: Subjective radiographic classifications of alveolar bone have been proposed and correlated with implant insertion torque (IT). The present diagnostic study aims to identify quantitative bone features influencing IT and to use these findings to develop an objective radiographic classification for predicting IT. METHODS: Demographics, panoramic radiographs (taken at the beginning of dental treatment), and cone-beam computed tomographic scans (taken for implant surgical planning) of 25 patients receiving 31 implants were analyzed. Bone samples retrieved from implant sites were assessed with dual x-ray absorptiometry, microcomputed tomography, and histology. Odds ratio, sensitivity, and specificity of all variables to predict high peak IT were assessed. RESULTS: A ridge cortical thickness >0.75 mm and a normal appearance of the inferior mandibular cortex were the most sensitive variables for predicting high peak IT (87.5% and 75%, respectively). A classification based on the combination of both variables presented high sensitivity (90.9%) and specificity (100%) for predicting IT. CONCLUSIONS: Within the limitations of this study, the results suggest that it is possible to predict IT accurately based on radiographic findings of the patient. This could be useful in the treatment plan of immediate loading cases.
Assuntos
Processo Alveolar/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/estatística & dados numéricos , Implantação Dentária Endóssea/métodos , Implantes Dentários , Radiografia Panorâmica/estatística & dados numéricos , Absorciometria de Fóton/estatística & dados numéricos , Adulto , Idoso , Processo Alveolar/patologia , Processo Alveolar/cirurgia , Fenômenos Biomecânicos , Biópsia/métodos , Densidade Óssea/fisiologia , Feminino , Seguimentos , Previsões , Humanos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Arcada Parcialmente Edêntula/diagnóstico por imagem , Arcada Parcialmente Edêntula/cirurgia , Masculino , Mandíbula/diagnóstico por imagem , Mandíbula/patologia , Mandíbula/cirurgia , Maxila/diagnóstico por imagem , Maxila/patologia , Maxila/cirurgia , Pessoa de Meia-Idade , Radiografia Dentária Digital/estatística & dados numéricos , Sensibilidade e Especificidade , Torque , Microtomografia por Raio-X/estatística & dados numéricosRESUMO
This in vivo study aimed to evaluate the influence of contact points on the approximal caries detection in primary molars, by comparing the performance of the DIAGNOdent pen and visual-tactile examination after tooth separation to bitewing radiography (BW). A total of 112 children were examined and 33 children were selected. In three periods (a, b, and c), 209 approximal surfaces were examined: (a) examiner 1 performed visual-tactile examination using the Nyvad criteria (EX1); examiner 2 used DIAGNOdent pen (LF1) and took BW; (b) 1 week later, after tooth separation, examiner 1 performed the second visual-tactile examination (EX2) and examiner 2 used DIAGNOdent again (LF2); (c) after tooth exfoliation, surfaces were directly examined using DIAGNOdent (LF3). Teeth were examined by computed microtomography as a reference standard. Analyses were based on diagnostic thresholds: D1: D 0 = health, D 1 D 4 = disease; D2: D 0 , D 1 = health, D 2 D 4 = disease; D3: D 0 D 2 = health, D 3 , D 4 = disease. At D1, the highest sensitivity/specificity were observed for EX1 (1.00)/LF3 (0.68), respectively. At D2, the highest sensitivity/ specificity were observed for LF3 (0.69)/BW (1.00), respectively. At D3, the highest sensitivity/specificity were observed for LF3 (0.78)/EX1, EX2 and BW (1.00). EX1 showed higher accuracy values than LF1, and EX2 showed similar values to LF2. We concluded that the visual-tactile examination showed better results in detecting sound surfaces and approximal caries lesions without tooth separation. However, the effectiveness of approximal caries lesion detection of both methods was increased by the absence of contact points. Therefore, regardless of the method of detection, orthodontic separating elastics should be used as a complementary tool for the diagnosis of approximal noncavitated lesions in primary molars.