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[PMID]:28742031
[Au] Autor:Larsson D; Spuhler JH; Petersson S; Nordenfur T; Colarieti-Tosti M; Hoffman J; Winter R; Larsson M
[Ti] Título:Patient-Specific Left Ventricular Flow Simulations From Transthoracic Echocardiography: Robustness Evaluation and Validation Against Ultrasound Doppler and Magnetic Resonance Imaging.
[So] Source:IEEE Trans Med Imaging;36(11):2261-2275, 2017 Nov.
[Is] ISSN:1558-254X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The combination of medical imaging with computational fluid dynamics (CFD) has enabled the study of 3-D blood flow on a patient-specific level. However, with models based on gated high-resolution data, the study of transient flows, and any model implementation into routine cardiac care, is challenging. This paper presents a novel pathway for patient-specific CFD modelling of the left ventricle (LV), using 4-D transthoracic echocardiography (TTE) as input modality. To evaluate the clinical usability, two sub-studies were performed. First, a robustness evaluation was performed, where repeated models with alternating input variables were generated for six subjects and changes in simulated output quantified. Second, a validation study was carried out, where the pathway accuracy was evaluated against pulsed-wave Doppler (100 subjects), and 2-D through-plane phase-contrast magnetic resonance imaging measurements over seven intraventricular planes (6 subjects). The robustness evaluation indicated a model deviation of <12%, with highest regional and temporal deviations at apical segments and at peak systole, respectively. The validation study showed an error of <11% (velocities <10 cm/s) for all subjects, with no significant regional or temporal differences observed. With the patient-specific pathway shown to provide robust output with high accuracy, and with the pathway dependent only on 4-D TTE, the method has a high potential to be used within future clinical studies on 3-D intraventricular flow patterns. To this, future model developments in the form of e.g., anatomically accurate LV valves may further enhance the clinical value of the simulations.
[Mh] Termos MeSH primário: Ecocardiografia/métodos
Ventrículos do Coração/diagnóstico por imagem
Processamento de Imagem Assistida por Computador/métodos
Modelagem Computacional Específica para o Paciente
Função Ventricular Esquerda/fisiologia
[Mh] Termos MeSH secundário: Adulto
Idoso
Algoritmos
Ecocardiografia Doppler em Cores/métodos
Seres Humanos
Imagem Cinética por Ressonância Magnética/métodos
Meia-Idade
Reprodutibilidade dos Testes
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180305
[Lr] Data última revisão:
180305
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170726
[St] Status:MEDLINE
[do] DOI:10.1109/TMI.2017.2718218


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[PMID]:29340526
[Au] Autor:Yousefi M; Yousefi M; Fogliatto FS; Ferreira RPM; Kim JH
[Ad] Endereço:Departamento de Engenharia de Produção e Transportes, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
[Ti] Título:Simulating the behavior of patients who leave a public hospital emergency department without being seen by a physician: a cellular automaton and agent-based framework.
[So] Source:Braz J Med Biol Res;51(3):e6961, 2018 Jan 11.
[Is] ISSN:1414-431X
[Cp] País de publicação:Brazil
[La] Idioma:eng
[Ab] Resumo:The objective of this study was to develop an agent based modeling (ABM) framework to simulate the behavior of patients who leave a public hospital emergency department (ED) without being seen (LWBS). In doing so, the study complements computer modeling and cellular automata (CA) techniques to simulate the behavior of patients in an ED. After verifying and validating the model by comparing it with data from a real case study, the significance of four preventive policies including increasing number of triage nurses, fast-track treatment, increasing the waiting room capacity and reducing treatment time were investigated by utilizing ordinary least squares regression. After applying the preventing policies in ED, an average of 42.14% reduction in the number of patients who leave without being seen and 6.05% reduction in the average length of stay (LOS) of patients was reported. This study is the first to apply CA in an ED simulation. Comparing the average LOS before and after applying CA with actual times from emergency department information system showed an 11% improvement. The simulation results indicated that the most effective approach to reduce the rate of LWBS is applying fast-track treatment. The ABM approach represents a flexible tool that can be constructed to reflect any given environment. It is also a support system for decision-makers to assess the relative impact of control strategies.
[Mh] Termos MeSH primário: Comportamento
Serviço Hospitalar de Emergência/organização & administração
Pacientes Desistentes do Tratamento/estatística & dados numéricos
Triagem/estatística & dados numéricos
[Mh] Termos MeSH secundário: Brasil
Simulação por Computador
Aglomeração
Tomada de Decisões
Técnicas de Apoio para a Decisão
Serviço Hospitalar de Emergência/estatística & dados numéricos
Hospitais Públicos
Seres Humanos
Tempo de Internação
Modelos Teóricos
Pacientes Desistentes do Tratamento/psicologia
Modelagem Computacional Específica para o Paciente
Treinamento por Simulação
Listas de Espera
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180301
[Lr] Data última revisão:
180301
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180118
[St] Status:MEDLINE


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[PMID]:29304062
[Au] Autor:Sindeev S; Arnold PG; Frolov S; Prothmann S; Liepsch D; Balasso A; Berg P; Kaczmarz S; Kirschke JS
[Ad] Endereço:Department of Biomedical Engineering, Tambov State Technical University, Tambov, Russia.
[Ti] Título:Phase-contrast MRI versus numerical simulation to quantify hemodynamical changes in cerebral aneurysms after flow diverter treatment.
[So] Source:PLoS One;13(1):e0190696, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cerebral aneurysms are a major risk factor for intracranial bleeding with devastating consequences for the patient. One recently established treatment is the implantation of flow-diverters (FD). Methods to predict their treatment success before or directly after implantation are not well investigated yet. The aim of this work was to quantitatively study hemodynamic parameters in patient-specific models of treated cerebral aneurysms and its correlation with the clinical outcome. Hemodynamics were evaluated using both computational fluid dynamics (CFD) and phase contrast (PC) MRI. CFD simulations and in vitro MRI measurements were done under similar flow conditions and results of both methods were comparatively analyzed. For preoperative and postoperative distribution of hemodynamic parameters, CFD simulations and PC-MRI velocity measurements showed similar results. In both cases where no occlusion of the aneurysm was observed after six months, a flow reduction of about 30-50% was found, while in the clinically successful case with complete occlusion of the aneurysm after 6 months, the flow reduction was about 80%. No vortex was observed in any of the three models after treatment. The results are in agreement with recent studies suggesting that CFD simulations can predict post-treatment aneurysm flow alteration already before implantation of a FD and PC-MRI could validate the predicted hemodynamic changes right after implantation of a FD.
[Mh] Termos MeSH primário: Circulação Cerebrovascular
Aneurisma Intracraniano/fisiopatologia
Aneurisma Intracraniano/cirurgia
Imagem por Ressonância Magnética
Modelos Neurológicos
Modelagem Computacional Específica para o Paciente
[Mh] Termos MeSH secundário: Adulto
Velocidade do Fluxo Sanguíneo
Circulação Cerebrovascular/fisiologia
Feminino
Seres Humanos
Aneurisma Intracraniano/diagnóstico por imagem
Imagem por Ressonância Magnética/instrumentação
Imagem por Ressonância Magnética/métodos
Masculino
Meia-Idade
Modelos Anatômicos
Imagens de Fantasmas
Impressão Tridimensional
Silicones
Resultado do Tratamento
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Silicones)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180210
[Lr] Data última revisão:
180210
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180106
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0190696


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[PMID]:29233836
[Au] Autor:Kolossváry M; Karády J; Szilveszter B; Kitslaar P; Hoffmann U; Merkely B; Maurovich-Horvat P
[Ad] Endereço:From the MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary (M.K., J.K., B.S., B.M., P.M.-H.); Department of Radiology, Leiden University Medical Center, The Netherlands (P.K.); Medis Medical Imaging Systems B.V., Leiden, The Netherlands
[Ti] Título:Radiomic Features Are Superior to Conventional Quantitative Computed Tomographic Metrics to Identify Coronary Plaques With Napkin-Ring Sign.
[So] Source:Circ Cardiovasc Imaging;10(12), 2017 Dec.
[Is] ISSN:1942-0080
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Napkin-ring sign (NRS) is an independent prognostic imaging marker of major adverse cardiac events. However, identification of NRS is challenging because of its qualitative nature. Radiomics is the process of extracting thousands of quantitative parameters from medical images to create big-data data sets that can identify distinct patterns in radiological images. Therefore, we sought to determine whether radiomic analysis improves the identification of NRS plaques. METHODS AND RESULTS: From 2674 patients referred to coronary computed tomographic angiography caused by stable chest pain, expert readers identified 30 patients with NRS plaques and matched these with 30 non-NRS plaques with similar degree of calcification, luminal obstruction, localization, and imaging parameters. All plaques were segmented manually, and image data information was analyzed using Radiomics Image Analysis package for the presence of 8 conventional and 4440 radiomic parameters. We used the permutation test of symmetry to assess differences between NRS and non-NRS plaques, whereas we calculated receiver-operating characteristics' area under the curve values to evaluate diagnostic accuracy. Bonferroni-corrected <0.0012 was considered significant. None of the conventional quantitative parameters but 20.6% (916/4440) of radiomic features were significantly different between NRS and non-NRS plaques. Almost half of these (418/916) reached an area under the curve value >0.80. Short- and long-run low gray-level emphasis and surface ratio of high attenuation voxels to total surface had the highest area under the curve values (0.918; 0.894 and 0.890, respectively). CONCLUSIONS: A large number of radiomic features are different between NRS and non-NRS plaques and exhibit excellent discriminatory value.
[Mh] Termos MeSH primário: Angiografia por Tomografia Computadorizada
Doença da Artéria Coronariana/diagnóstico por imagem
Mineração de Dados/métodos
Técnicas de Apoio para a Decisão
Placa Aterosclerótica/diagnóstico por imagem
Interpretação de Imagem Radiográfica Assistida por Computador/métodos
[Mh] Termos MeSH secundário: Idoso
Feminino
Seres Humanos
Masculino
Meia-Idade
Modelagem Computacional Específica para o Paciente
Medicina de Precisão
Valor Preditivo dos Testes
Prognóstico
Estudos Retrospectivos
Software
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1712
[Cu] Atualização por classe:180210
[Lr] Data última revisão:
180210
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171214
[St] Status:MEDLINE


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[PMID]:29205211
[Au] Autor:Caruso MV; Serra R; Perri P; Buffone G; Caliò FG; DE Franciscis S; Fragomeni F
[Ad] Endereço:Department of Medical and Surgical Sciences, "Magna Graecia" University, Viale Europa, Catanzaro, Italy.
[Ti] Título:A computational evaluation of sedentary lifestyle effects on carotid hemodynamics and atherosclerotic events incidence.
[So] Source:Acta Bioeng Biomech;19(3):42-52, 2017.
[Is] ISSN:1509-409X
[Cp] País de publicação:Poland
[La] Idioma:eng
[Ab] Resumo:PURPOSE: Hemodynamics has a key role in atheropathogenesis. Indeed, atherosclerotic phenomena occur in vessels characterized by complex geometry and flow pattern, like the carotid bifurcation. Moreover, lifestyle is a significant risk factor. The aim of this study is to evaluate the hemodynamic effects due to two sedentary lifestyles - sitting and standing positions - in the carotid bifurcation in order to identify the worst condition and to investigate the atherosclerosis incidence. METHODS: The computational fluid dynamics (CFD) was chosen to carry out the analysis, in which in vivo non-invasive measurements were used as boundary conditions. Furthermore, to compare the two conditions, one patient-specific 3D model of a carotid bifurcation was reconstructed starting from computer tomography. Different mechanical indicators, correlated with atherosclerosis incidence, were calculated in addition to flow pattern and pressure distribution: the time average wall shear stress (TAWSS), the oscillatory shear index (OSI) and the relative residence time (RRT). RESULTS: The results showed that the bulb and the external carotid artery emergence are the most probable regions in which atherosclerotic events could happen. Indeed, low velocity and WSS values, high OSI and, as a consequence, areas with chaotic-swirling flow, with stasis (high RRT), occur. Moreover, the sitting position is the worst condition: considering a cardiac cycle, TAWSS is less than 17.2% and OSI and RRT are greater than 17.5% and 21.2%, respectively. CONCLUSIONS: This study suggests that if a person spends much time in the sitting position, a high risk of plaque formation and, consequently, of stenosis could happen.
[Mh] Termos MeSH primário: Velocidade do Fluxo Sanguíneo
Pressão Sanguínea
Artérias Carótidas/fisiopatologia
Doenças das Artérias Carótidas/epidemiologia
Doenças das Artérias Carótidas/fisiopatologia
Modelos Cardiovasculares
Estilo de Vida Sedentário
[Mh] Termos MeSH secundário: Doenças das Artérias Carótidas/diagnóstico por imagem
Simulação por Computador
Feminino
Seres Humanos
Itália/epidemiologia
Masculino
Meia-Idade
Modelagem Computacional Específica para o Paciente
Prevalência
Reprodutibilidade dos Testes
Medição de Risco/métodos
Sensibilidade e Especificidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180129
[Lr] Data última revisão:
180129
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171206
[St] Status:MEDLINE


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[PMID]:28451863
[Au] Autor:Lansdown DA; Pedoia V; Zaid M; Amano K; Souza RB; Li X; Ma CB
[Ad] Endereço:Department of Orthopaedic Surgery, University of California, San Francisco, 1500 Owens Street, San Francisco, CA, 94158, USA. Drew.lansdown@gmail.com.
[Ti] Título:Variations in Knee Kinematics After ACL Injury and After Reconstruction Are Correlated With Bone Shape Differences.
[So] Source:Clin Orthop Relat Res;475(10):2427-2435, 2017 Oct.
[Is] ISSN:1528-1132
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: The factors that contribute to the abnormal knee kinematics after anterior cruciate ligament (ACL) injury and ACL reconstruction remain unclear. Bone shape has been implicated in the development of hip and knee osteoarthritis, although there is little knowledge about the effects of bone shape on knee kinematics after ACL injury and after ACL reconstruction. QUESTIONS/QUESTIONS: (1) What is the relationship between bony morphology with alterations in knee kinematics after ACL injury? (2) Are baseline bone shape features related to abnormal knee kinematics at 12 months after ACL reconstruction? METHODS: Thirty-eight patients (29 ± 8 years, 21 men) were prospectively followed after acute ACL injury and before ligamentous reconstruction. Patients were excluded if there was a history of prior knee ligamentous injury, a history of inflammatory arthritis, associated meniscal tears that would require repair, or any prior knee surgery on either the injured or contralateral side. In total, 54 patients were recruited with 42 (78%) patients completing 1-year followup and four patients excluded as a result of incomplete or unusable imaging data. MR images were obtained for the bilateral knees at two time points 1 year apart for both the injured (after injury but before reconstruction and 1 year after reconstruction) and contralateral uninjured knees. Kinematic MRI was performed with the knee loaded with 25% of total body weight, and static images were obtained in full extension and in 30° of flexion. The side-to-side difference (SSD) between tibial position in the extended and flexed positions was determined for each patient. Twenty shape features, referred to as modes, for the tibia and femur each were extracted independently from presurgery scans with the principal component analysis-based statistical shape modeling algorithm. Spearman rank correlations were used to evaluate the relationship between the SSD in tibial position and bone shape features with significance defined as p < 0.05. Each of the shape features (referred to as the bone and mode number such as Femur 18 for the 18th unique femoral bone shape) associated with differences in tibial position was then investigated by modeling the mean shape ± 3 SDs. RESULTS: Two of the 20 specific femur bone shape features (Femur 10, Femur 18) and two of the 20 specific tibial bone shape features (Tibia 19, Tibia 20) were associated with an increasingly anterior SSD in the tibial position for the patients with ACL injury before surgical treatment. The shape features described by these modes include the superoinferior height of the medial femoral condyle (Femur 18; ρ = 0.33, p = 0.040); the length of the anterior aspect of the lateral tibial plateau (Tibia 20; ρ = -0.35, p = 0.034); the sphericity of the medial femoral condyle (Femur 10; ρ = -0.52, p < 0.001); and tibial slope (Tibia 19; ρ = 0.34; p = 0.036). One year after surgical treatment, there were two of 20 femoral shape features that were associated with SSD in the tibial position in extension (Femur 10, Femur 18), one of 20 femoral shape features associated with SSD in the tibial position in flexion (Femur 10), and three of 20 tibial shape features associated with SSD in the tibial position in flexion (Tibia 2, Tibia 4, Tibia 19). The shape features described by these modes include the sphericity of the medial femoral condyle (Femur 10; ρ = -0.38, p = 0.020); the superoinferior height of the medial femoral condyle (Femur 18; ρ = 0.34, p = 0.035); the height of the medial tibial plateau (Tibia 2; ρ = -0.32, p = 0.048); the AP length of the lateral tibial plateau (Tibia 4; ρ = -0.37, p = 0.021); and tibial slope (Tibia 19; ρ = 0.34, p = 0.038). CONCLUSIONS: We have observed multiple bone shape features in the tibia and the femur that may be associated with abnormal knee kinematics after ACL injury and ACL reconstruction. Future directions of research will include the influence of bony morphology on clinical symptoms of instability in patients with and without ACL reconstruction and the long-term evaluation of these shape factors to better determine specific contributions to posttraumatic arthritis and graft failure. LEVEL OF EVIDENCE: Level II, therapeutic study.
[Mh] Termos MeSH primário: Lesões do Ligamento Cruzado Anterior/cirurgia
Reconstrução do Ligamento Cruzado Anterior
Ligamento Cruzado Anterior/cirurgia
Fêmur/diagnóstico por imagem
Articulação do Joelho/cirurgia
Imagem por Ressonância Magnética
Tíbia/diagnóstico por imagem
[Mh] Termos MeSH secundário: Adulto
Algoritmos
Ligamento Cruzado Anterior/diagnóstico por imagem
Ligamento Cruzado Anterior/fisiopatologia
Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem
Lesões do Ligamento Cruzado Anterior/fisiopatologia
Reconstrução do Ligamento Cruzado Anterior/efeitos adversos
Fenômenos Biomecânicos
Feminino
Fêmur/fisiopatologia
Seres Humanos
Interpretação de Imagem Assistida por Computador
Articulação do Joelho/diagnóstico por imagem
Articulação do Joelho/fisiopatologia
Masculino
Modelagem Computacional Específica para o Paciente
Complicações Pós-Operatórias/etiologia
Complicações Pós-Operatórias/fisiopatologia
Análise de Componente Principal
Estudos Prospectivos
Recuperação de Função Fisiológica
Fatores de Risco
Tíbia/fisiopatologia
Fatores de Tempo
Resultado do Tratamento
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1712
[Cu] Atualização por classe:180124
[Lr] Data última revisão:
180124
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE
[do] DOI:10.1007/s11999-017-5368-8


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[PMID]:27771399
[Au] Autor:Ko BS; Cameron JD; Munnur RK; Wong DTL; Fujisawa Y; Sakaguchi T; Hirohata K; Hislop-Jambrich J; Fujimoto S; Takamura K; Crossett M; Leung M; Kuganesan A; Malaiapan Y; Nasis A; Troupis J; Meredith IT; Seneviratne SK
[Ad] Endereço:Monash Cardiovascular Research Centre, MonashHEART, Department of Medicine, Monash Medical Centre, Monash Health, and Monash University, Melbourne, Victoria, Australia. Electronic address: brian.ko@monashhealth.org.
[Ti] Título:Noninvasive CT-Derived FFR Based on Structural and Fluid Analysis: A Comparison With Invasive FFR for Detection of Functionally Significant Stenosis.
[So] Source:JACC Cardiovasc Imaging;10(6):663-673, 2017 Jun.
[Is] ISSN:1876-7591
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:OBJECTIVES: This study describes the feasibility and accuracy of a novel computed tomography (CT) fractional flow reserve (FFR) technique based on alternative boundary conditions. BACKGROUND: Techniques used to compute FFR based on images acquired from coronary computed tomography angiography (CTA) are described. Boundary conditions were typically determined by allometric scaling laws and assumptions regarding microvascular resistance. Alternatively, boundary conditions can be derived from the structural deformation of coronary lumen and aorta, although its accuracy remains unknown. METHODS: Forty-two patients (78 vessels) in a single institution prospectively underwent 320-detector coronary CTA and FFR. Deformation of coronary cross-sectional lumen and aorta, computed from coronary CTA images acquired over diastole, was used to determine the boundary conditions based on hierarchical Bayes modeling. CT-FFR was derived using a reduced order model performed using a standard desktop computer and dedicated software. First, 12 patients (20 vessels) formed the derivation cohort to determine optimal CT-FFR threshold with which to detect functional stenosis, defined as FFR of ≤0.8, which was validated in the subsequent 30 patients (58 vessels). RESULTS: Derivation cohort results demonstrated optimal threshold for CT-FFR was 0.8 with 67% sensitivity and 91% specificity. In the validation cohort, CT-FFR was successfully computed in 56 of 58 vessels (97%). Compared with coronary CTA, CT-FFR at ≤0.8 demonstrated a higher specificity (87% vs. 74%, respectively) and positive predictive value (74% vs. 60%, respectively), with comparable sensitivity (78% vs. 79%, respectively), negative predictive value (89% vs. 88%, respectively), and accuracy (area under the curve: 0.88 vs. 0.77, respectively; p = 0.22). Based on Bland-Altman analysis, mean intraobserver and interobserver variability values for CT-FFR were, respectively, -0.02 ± 0.05 (95% limits of agreement: -0.12 to 0.08) and 0.03 ± 0.06 (95% limits: 0.07 to 0.19). Mean time per patient for CT-FFR analysis was 27.07 ± 7.54 min. CONCLUSIONS: CT-FFR based on alternative boundary conditions and reduced-order fluid model is feasible, highly reproducible, and may be accurate in detecting FFR ≤ 0.8. It requires a short processing time and can be completed at point-of-care. Further validation is required in large prospective multicenter settings.
[Mh] Termos MeSH primário: Angiografia por Tomografia Computadorizada/métodos
Angiografia Coronária/métodos
Estenose Coronária/diagnóstico por imagem
Vasos Coronários/diagnóstico por imagem
Reserva Fracionada de Fluxo Miocárdico
Tomografia Computadorizada Multidetectores/métodos
Interpretação de Imagem Radiográfica Assistida por Computador/métodos
[Mh] Termos MeSH secundário: Adulto
Idoso
Idoso de 80 Anos ou mais
Área Sob a Curva
Estenose Coronária/fisiopatologia
Vasos Coronários/fisiopatologia
Estudos de Viabilidade
Feminino
Seres Humanos
Masculino
Meia-Idade
Modelos Cardiovasculares
Variações Dependentes do Observador
Modelagem Computacional Específica para o Paciente
Valor Preditivo dos Testes
Prognóstico
Estudos Prospectivos
Curva ROC
Reprodutibilidade dos Testes
Índice de Gravidade de Doença
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE; VALIDATION STUDIES
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180105
[Lr] Data última revisão:
180105
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161025
[St] Status:MEDLINE


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[PMID]:28448498
[Au] Autor:Albers DJ; Levine M; Gluckman B; Ginsberg H; Hripcsak G; Mamykina L
[Ad] Endereço:Department of Biomedical Informatics, Columbia University, New York, New York, United States of America.
[Ti] Título:Personalized glucose forecasting for type 2 diabetes using data assimilation.
[So] Source:PLoS Comput Biol;13(4):e1005232, 2017 Apr.
[Is] ISSN:1553-7358
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Type 2 diabetes leads to premature death and reduced quality of life for 8% of Americans. Nutrition management is critical to maintaining glycemic control, yet it is difficult to achieve due to the high individual differences in glycemic response to nutrition. Anticipating glycemic impact of different meals can be challenging not only for individuals with diabetes, but also for expert diabetes educators. Personalized computational models that can accurately forecast an impact of a given meal on an individual's blood glucose levels can serve as the engine for a new generation of decision support tools for individuals with diabetes. However, to be useful in practice, these computational engines need to generate accurate forecasts based on limited datasets consistent with typical self-monitoring practices of individuals with type 2 diabetes. This paper uses three forecasting machines: (i) data assimilation, a technique borrowed from atmospheric physics and engineering that uses Bayesian modeling to infuse data with human knowledge represented in a mechanistic model, to generate real-time, personalized, adaptable glucose forecasts; (ii) model averaging of data assimilation output; and (iii) dynamical Gaussian process model regression. The proposed data assimilation machine, the primary focus of the paper, uses a modified dual unscented Kalman filter to estimate states and parameters, personalizing the mechanistic models. Model selection is used to make a personalized model selection for the individual and their measurement characteristics. The data assimilation forecasts are empirically evaluated against actual postprandial glucose measurements captured by individuals with type 2 diabetes, and against predictions generated by experienced diabetes educators after reviewing a set of historical nutritional records and glucose measurements for the same individual. The evaluation suggests that the data assimilation forecasts compare well with specific glucose measurements and match or exceed in accuracy expert forecasts. We conclude by examining ways to present predictions as forecast-derived range quantities and evaluate the comparative advantages of these ranges.
[Mh] Termos MeSH primário: Glicemia/metabolismo
Biologia Computacional/métodos
Diabetes Mellitus Tipo 2/metabolismo
Modelagem Computacional Específica para o Paciente
[Mh] Termos MeSH secundário: Adulto
Algoritmos
Glicemia/análise
Feminino
Seres Humanos
Insulina/metabolismo
Masculino
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Blood Glucose); 0 (Insulin)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:171228
[Lr] Data última revisão:
171228
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170428
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pcbi.1005232


  9 / 413 MEDLINE  
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[PMID]:28948516
[Au] Autor:Chen X; Reddy AS; Kontaxis A; Choi DS; Wright T; Dines DM; Warren RF; Berhouet J; Gulotta LV
[Ad] Endereço:Hospital for Special Surgery, 535 East 70 Street, New York, NY, 10021, USA. chenx@hss.edu.
[Ti] Título:Version Correction via Eccentric Reaming Compromises Remaining Bone Quality in B2 Glenoids: A Computational Study.
[So] Source:Clin Orthop Relat Res;475(12):3090-3099, 2017 Dec.
[Is] ISSN:1528-1132
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Version correction via eccentric reaming reduces clinically important retroversion in Walch type B2 glenoids (those with substantial glenoid retroversion and a second, sclerotic neoglenoid cavity) before total shoulder arthroplasty (TSA). Clinically, an increased risk of glenoid component loosening in B2 glenoids was hypothesized to be the result of compromised glenoid bone quality attributable to eccentric reaming. However, no established guidelines exist regarding how much version correction can be applied without compromising the quality of glenoid bone. QUESTIONS/PURPOSES: (1) How does version correction correlate to the reaming depth and the volume of resected bone during eccentric reaming of B2 glenoids? (2) How does version correction affect the density of the remaining glenoid bone? (3) How does version correction affect the spatial distribution of high-quality bone in the remaining glenoid? METHODS: CT scans of 25 patients identified with Walch type B2 glenoids (age, 68 ± 9 years; 14 males, 11 females) were selected from a cohort of 111 patients (age, 69 ± 10 years; 50 males, 61 females) with primary shoulder osteoarthritis who underwent TSA. Virtual TSA with version corrections of 0°, 5°, 10°, and 15° was performed on 25 CT-reconstructed three-dimensional models of B2 scapulae. After simulated eccentric reaming at each version correction angle, bone density (Hounsfield units [HUs]) was analyzed in five adjacent 1-mm layers under the reamed glenoid surface. Remaining high-quality bone (> 650 HUs) distribution in each 1-mm layer at different version corrections was observed on spatial distribution maps. RESULTS: Larger version corrections required more bone resection, especially from the anterior glenoid. Mean bone densities in the first 1-mm bone bed under the reamed surface were lower with 10° (523.3 ± 79.9 HUs) and 15° (479.5 ± 81.0 HUs) version corrections relative to 0° (0°, 609.0 ± 103.9 HUs; mean difference between 0° and 15°, 129.5 HUs [95% CI, 46.3-212.8 HUs], p < 0.001; mean difference between 0° and 10°, 85.7 HUs [95% CI, 8.6-162.9 HUs], p = 0.021) version correction. Similar results were observed for the second 1-mm bone bed. Spatial distribution maps qualitatively showed a decreased frequency of high-quality bone in the anterior glenoid as version correction increased. CONCLUSIONS: A version correction as low as 10° was shown to reduce the density of the glenoid bone bed for TSA glenoid fixation in our computational study that simulated reaming on CT-reconstructed B2 glenoid models. Increased version correction resulted in gradual depletion of high-quality bone from the anterior region of B2 glenoids. CLINICAL RELEVANCE: This computational study of eccentric reaming of the glenoid before TSA quantitatively showed glenoid bone quality is sensitive to version correction via simulated eccentric reaming. The bone density results of our study may benefit surgeons to better plan TSA on B2 glenoids needing durable bone support, and help to clarify goals for development of precision surgical tools.
[Mh] Termos MeSH primário: Artroplastia de Substituição/métodos
Cavidade Glenoide/cirurgia
Osteoartrite/cirurgia
Osteotomia/métodos
Modelagem Computacional Específica para o Paciente
Articulação do Ombro/cirurgia
Cirurgia Assistida por Computador
[Mh] Termos MeSH secundário: Idoso
Artroplastia de Substituição/efeitos adversos
Artroplastia de Substituição/instrumentação
Densidade Óssea
Feminino
Cavidade Glenoide/diagnóstico por imagem
Cavidade Glenoide/fisiopatologia
Seres Humanos
Imagem Tridimensional
Masculino
Meia-Idade
Osteoartrite/diagnóstico por imagem
Osteoartrite/fisiopatologia
Osteotomia/efeitos adversos
Desenho de Prótese
Interpretação de Imagem Radiográfica Assistida por Computador
Articulação do Ombro/diagnóstico por imagem
Articulação do Ombro/fisiopatologia
Prótese de Ombro
Cirurgia Assistida por Computador/efeitos adversos
Tomografia Computadorizada por Raios X
Resultado do Tratamento
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171117
[Lr] Data última revisão:
171117
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:170927
[St] Status:MEDLINE
[do] DOI:10.1007/s11999-017-5510-7


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[PMID]:28796727
[Au] Autor:Tan WJ; Dorajoo SR; Chee MYM; Tan WS; Foo FJ; Tang CL; Chew MH
[Ad] Endereço:1 Department of Colorectal Surgery, Singapore General Hospital, Singapore 2 Department of Pharmacy, National University of Singapore, Singapore 3 Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
[Ti] Título:A Novel Derivation Predicting Survival After Primary Tumor Resection in Stage IV Colorectal Cancer: Validation of a Prognostic Scoring Model and an Online Calculator to Provide Individualized Survival Estimation.
[So] Source:Dis Colon Rectum;60(9):895-904, 2017 Sep.
[Is] ISSN:1530-0358
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: A prognostic scoring model has been devised previously to predict survival following primary tumor resection in patients with metastatic colorectal cancer and unresectable metastases. This has yet to be validated. OBJECTIVE: The main objectives of this study are to validate the proposed prognostic scoring model and create an interactive online calculator to estimate an individual's survival after primary tumor resection. DESIGN: Clinical data and survival outcomes of patients were extracted from a prospectively maintained database. Patients were categorized into good, moderate, or poor survivor groups based on the previously proposed scoring algorithm. Discrimination was assessed and recalibration was performed, with the recalibrated model implemented as an interactive Web application to provide individualized survival probability. SETTINGS: This study was conducted at a tertiary referral center. PATIENTS: The study included 324 consecutive patients with metastatic colorectal carcinoma and unresectable metastases who underwent primary tumor resection between January 2008 and December 2013. MAIN OUTCOME MEASURES: The primary outcome measured was overall survival. RESULTS: Three hundred twenty-four patients were included in the study. Median survival in the good, moderate, and poor prognostic groups was 56.8, 25.7, and 19.9 months (log rank test, p = 0.003). The κ statistic was 0.638 and RD was 0.101. Significant differences in survival were found between the moderate and good prognostic groups (HR, 2.79; 95% CI, 1.51-5.15; p = 0.001) and between poor and good prognostic groups (HR, 4.12; 95% CI, 1.98-8.55; p < 0.001). The model was implemented as an interactive online calculator to provide individualized survival estimation after primary tumor resection (http://bit.ly/Stage4PrognosticScore). LIMITATIONS: Selection bias and single-center data preclude the generalizability of the proposed model. Information regarding the severity or likelihood of developing symptoms from the primary tumor were also not accounted for in the prognostic scoring model proposed. CONCLUSIONS: The prognostic scoring model provides good prognostic stratification of survival after primary tumor resection and may be a useful tool to predict survival after primary tumor resection. See Video Abstract at http://links.lww.com/DCR/A330.
[Mh] Termos MeSH primário: Colectomia
Neoplasias Colorretais
Modelos de Riscos Proporcionais
[Mh] Termos MeSH secundário: Idoso
Colectomia/efeitos adversos
Colectomia/métodos
Neoplasias Colorretais/diagnóstico
Neoplasias Colorretais/cirurgia
Feminino
Seres Humanos
Masculino
Meia-Idade
Aplicativos Móveis
Modelagem Computacional Específica para o Paciente/normas
Valor Preditivo dos Testes
Prognóstico
Projetos de Pesquisa
Medição de Risco/métodos
Medição de Risco/normas
Singapura
[Pt] Tipo de publicação:JOURNAL ARTICLE; VALIDATION STUDIES
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170907
[Lr] Data última revisão:
170907
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170811
[St] Status:MEDLINE
[do] DOI:10.1097/DCR.0000000000000821



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