2,814 research outputs found

    A Predictive Model for Assessment of Successful Outcome in Posterior Spinal Fusion Surgery

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    Background: Low back pain is a common problem in many people. Neurosurgeons recommend posterior spinal fusion (PSF) surgery as one of the therapeutic strategies to the patients with low back pain. Due to the high risk of this type of surgery and the critical importance of making the right decision, accurate prediction of the surgical outcome is one of the main concerns for the neurosurgeons.Methods: In this study, 12 types of multi-layer perceptron (MLP) networks and 66 radial basis function (RBF) networks as the types of artificial neural network methods and a logistic regression (LR) model created and compared to predict the satisfaction with PSF surgery as one of the most well-known spinal surgeries.Results: The most important clinical and radiologic features as twenty-seven factors for 480 patients (150 males, 330 females; mean age 52.32 ± 8.39 years) were considered as the model inputs that included: age, sex, type of disorder, duration of symptoms, job, walking distance without pain (WDP), walking distance without sensory (WDS) disorders, visual analog scale (VAS) scores, Japanese Orthopaedic Association (JOA) score, diabetes, smoking, knee pain (KP), pelvic pain (PP), osteoporosis, spinal deformity and etc. The indexes such as receiver operating characteristic–area under curve (ROC-AUC), positive predictive value, negative predictive value and accuracy calculated to determine the best model. Postsurgical satisfaction was 77.5% at 6 months follow-up. The patients divided into the training, testing, and validation data sets.Conclusion: The findings showed that the MLP model performed better in comparison with RBF and LR models for prediction of PSF surgery.Keywords: Posterior spinal fusion surgery (PSF); Prediction, Surgical satisfaction; Multi-layer perceptron (MLP); Logistic regression (LR) (PDF) A Predictive Model for Assessment of Successful Outcome in Posterior Spinal Fusion Surgery. Available from: https://www.researchgate.net/publication/325679954_A_Predictive_Model_for_Assessment_of_Successful_Outcome_in_Posterior_Spinal_Fusion_Surgery [accessed Jul 11 2019].Peer reviewe

    Recognition of Morphometric Vertebral Fractures by Artificial Neural Networks: Analysis from GISMO Lombardia Database

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    BACKGROUND: It is known that bone mineral density (BMD) predicts the fracture's risk only partially and the severity and number of vertebral fractures are predictive of subsequent osteoporotic fractures (OF). Spinal deformity index (SDI) integrates the severity and number of morphometric vertebral fractures. Nowadays, there is interest in developing algorithms that use traditional statistics for predicting OF. Some studies suggest their poor sensitivity. Artificial Neural Networks (ANNs) could represent an alternative. So far, no study investigated ANNs ability in predicting OF and SDI. The aim of the present study is to compare ANNs and Logistic Regression (LR) in recognising, on the basis of osteoporotic risk-factors and other clinical information, patients with SDI≥1 and SDI≥5 from those with SDI = 0. METHODOLOGY: We compared ANNs prognostic performance with that of LR in identifying SDI≥1/SDI≥5 in 372 women with postmenopausal-osteoporosis (SDI≥1, n = 176; SDI = 0, n = 196; SDI≥5, n = 51), using 45 variables (44 clinical parameters plus BMD). ANNs were allowed to choose relevant input data automatically (TWIST-system-Semeion). Among 45 variables, 17 and 25 were selected by TWIST-system-Semeion, in SDI≥1 vs SDI = 0 (first) and SDI≥5 vs SDI = 0 (second) analysis. In the first analysis sensitivity of LR and ANNs was 35.8% and 72.5%, specificity 76.5% and 78.5% and accuracy 56.2% and 75.5%, respectively. In the second analysis, sensitivity of LR and ANNs was 37.3% and 74.8%, specificity 90.3% and 87.8%, and accuracy 63.8% and 81.3%, respectively. CONCLUSIONS: ANNs showed a better performance in identifying both SDI≥1 and SDI≥5, with a higher sensitivity, suggesting its promising role in the development of algorithm for predicting OF

    치과용 파노라마 방사선 사진에서 골다공증 선별을 위한 심층 합성곱 신경망(deep CNN)의 전이학습 전략

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    학위논문 (박사) -- 서울대학교 대학원 : 의과대학 의학과, 2020. 8. 최진욱.Osteoporosis is a metabolic bone disease characterized by low bone mass and disruption in bone micro-architecture. Clinical diagnostic methods for osteoporosis are expensive and therefore have limited availability in population. Recent studies have shown that Dental Panoramic Radiographs (DPRs) can provide the bone density change clues in bone structure analysis. This study aims to evaluate the discriminating performance of deep convolutional neural networks (CNNs), employed with various transfer learning strategies, on the classification of specific features of osteoporosis in DPRs. For objective labeling, we collected a dataset containing 680 images from different patients who underwent both skeletal bone mineral density and digital panoramic radiographic examinations at the Korea University Ansan Hospital between 2009 and 2018. In order to select the backbone convolutional neural network which is the basis for applying the transfer learning, we conducted preliminary experiments on the three convolutional neural networks, VGG-16, Resnet50, and Xception networks, which were frequently used in image classification. Since VGG-16 showed the best AUC value in the classification experiment conducted without transfer learning, the transfer learning using the fine-tunning technique was tested using VGG-16 as the backbone network. In order to find the optimal fine-tuning degree in the VGG-16 network, a total of six fine-tuning applied transfer learning groups were set according to the number of fine-tuning blocks in the VGG-16 with five blocks as follows: A group that does not perform fine-tuning at all (VGG-16-TF0), a group that fine-tunes the last 1 block (VGG-16-TF1), a group that fine-tuning the last 2 blocks (VGG-16-TF2), a group that fine-tuning the last 3 blocks (VGG-16-TF3), a group that fine-tuning the last 4 blocks (VGG-16-TF4), and a group that performs fine-tuning all 5 blocks (VGG-16-SCR).The best performing model (VGG-16-TF2) achieved an overall area under the receiver operating characteristic of 0.858. In this study, transfer learning and optimal fine-tuning improved the performance of a deep CNN for screening osteoporosis in DPR images. In addition, using the gradient-weighted class activation mapping technique, a visual interpretation of the best performing deep CNN model indicated that the model relied on image features in the lower left and right border of the mandibular. This result suggests that deep learning-based assessment of DPR images could be useful and reliable in the automated screening of osteoporosis patients.골다공증은 골밀도가 낮고 골 미세 구조의 붕괴가 특징 인 대사성 골 질환입니다. 그러나, 골다공증에 대한 임상 진단 방법중에 하나인 DXA 검사는 대형의 검사용 엑스레이 장비가 별도로 필요하고 검사비용이 높아, 해당 검사의 이용성에 제한성이 있습니다. 최근 연구에 따르면 치과 파노라마 방사선 사진 (DPR) 또한 골 밀도 변화를 예측 할 수 있다고 연구되었습니다. 이에 본 연구는 DPR에서 골다공증에 의한 골 밀도 변화에 따른 엑스레이 영상 특이성 분류에 다양한 전이 학습전략을 적용한 심층 합성곱 신경망 (CNN)의 분류 성능을 평가하는 것에 목표로 두었습니다. 합습 및 검증용 데이터의 객관적인 라벨링을 위해 2009년부터 2018년까지 고려 대학교 안산 병원에서 골밀도 검사와 디지털 파노라마 방사선 촬영을 6개월 이내에 동시에 시행한 환자들로부터 680개의 데이터 세트를 수집했습니다. 전이 학습 전 기본이 되는 합성곱 신경망을 선택하기 위해 이미지 분류에 자주 사용되는 3개의 합성곱 신경망 인 VGG-16, Resnet-50 및 Xception 네트워크에 대해 전이학습이 없는 상태로 사전 분류성능 평가를 수행했습니다. VGG-16은 전이 학습 없이 수행 된 분류 성능 평가에서 다른 2개의 네트워크에 비해 높은 AUC 값을 보여 주었기에, 해당 네트워크를 백본(back-bone) 네트워크로 사용하여 전이학습 효과를 비교 분석하였습니다. 백본 네트워크에서 최적의 fine-tuning 정도를 찾기 위해 VGG-16에 fine-tuning이 적용 가능한 블록 수에 따라 총 6 개의 fine-tuning 적용 전이 학습 그룹이 다음과 같이 설정 하였습니다. fine-tuning을 전혀 하지 않는 그룹 (VGG16-TR0), 마지막 1 블록을 fine-tuning 하는 그룹 (VGG-16-TF1), 마지막 2 블록을 fine-tuning 하는 그룹 (VGG-16-TF2), 마지막 3 개 블록을 fine-tuning하는 그룹 (VGG-16-TF3), 마지막 4 개 블록을 fine-tuning하는 그룹 (VGG-16-TF4) 및 5 개 블록 모두를 fine-tuning하는 그룹 (VGG16-TR5). 실험 결과 최고 성능 모델 은 VGG-16-TF2 였으며, 분류 성능 값의 하나인 AUC 값이 0.858를 달성했습니다. 본 연구를 통하여 학습용 데이터 수에 제한이 있더라도, 전이 학습 및 fine-tuning을 통하여 DPR 이미지를 이용한 골다공증 스크리닝 성능의 개선이 가능함을 보여주었습니다. 또한 gradiant-CAM 기법을 이용하여 성능이 가장 우수한 CNN 모델의 시각적 해석을 통하여, DPR 이미지 상에서 적절한 골다공증의 분류성능은 하악골의 왼쪽 및 오른쪽 하연 경계에있는 이미지에 의존한다는 것을 확인 할 수 있었습니다. 본 결과는 DPR 이미지의 딥 러닝 기반 평가가 골다공증 환자의 자동 선별에 유용하고 신뢰할 수 있음을 시사 하였습니다.Chapter 1. Introduction 1 Chapter 2. Materials and Methods 8 2.1 Dataset Collection 8 2.2 Image Preprocessing 9 2.3 Cross validation 11 2.4 Back-bone Convolutional Neural Networks 14 2.5 Evaluation 16 2.6 Visualizing Model Decisions 18 Chapter 3. Results 19 3.1 Clinical and Demographic Characteristics 19 3.2 Back-bone Convolutional Neural Networks 20 3.3 Fine-Tuning of Transferred deep CNN 22 3.4 Evaluation 27 3.5 Visualizing Model Decisions 30 Chapter 4. Discussion 33 Chapter 5. Conclusion 42 References 42 Abstract 51Docto

    Non-communicable Diseases, Big Data and Artificial Intelligence

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    This reprint includes 15 articles in the field of non-communicable Diseases, big data, and artificial intelligence, overviewing the most recent advances in the field of AI and their application potential in 3P medicine

    Bone strain index as a predictor of further vertebral fracture in osteoporotic women: An artificial intelligence-based analysis

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    Background Osteoporosis is an asymptomatic disease of high prevalence and incidence, leading to bone fractures burdened by high mortality and disability, mainly when several subsequent fractures occur. A fragility fracture predictive model, Artificial Intelligence-based, to identify dual X-ray absorptiometry (DXA) variables able to characterise those patients who are prone to further fractures called Bone Strain Index, was evaluated in this study. Methods In a prospective, longitudinal, multicentric study 172 female outpatients with at least one vertebral fracture at the first observation were enrolled. They performed a spine X-ray to calculate spine deformity index (SDI) and a lumbar and femoral DXA scan to assess bone mineral density (BMD) and bone strain index (BSI) at baseline and after a follow-up period of 3 years in average. At the end of the follow-up, 93 women developed a further vertebral fracture. The further vertebral fracture was considered as one unit increase of SDI. We assessed the predictive capacity of supervised Artificial Neural Networks (ANNs) to distinguish women who developed a further fracture from those without it, and to detect those variables providing the maximal amount of relevant information to discriminate the two groups. ANNs choose appropriate input data automatically (TWIST-system, Training With Input Selection and Testing). Moreover, we built a semantic connectivity map usingthe Auto Contractive Map to provide further insights about the convoluted connections between the osteoporotic variables under consideration and the two scenarios (further fracture vs no further fracture). Results TWIST system selected 5 out of 13 available variables: age, menopause age, BMI, FTot BMC, FTot BSI. With training testing procedure, ANNs reached predictive accuracy of 79.36%, with a sensitivity of 75% and a specificity of 83.72%. The semantic connectivity map highlighted the role of BSI in predicting the risk of a further fracture. Conclusions Artificial Intelligence is a useful method to analyse a complex system like that regarding osteoporosis, able to identify patients prone to a further fragility fracture. BSI appears to be a useful DXA index in identifying those patients who are at risk of further vertebral fractures. Copyright

    Deep Learning for Osteoporosis Classification Using Hip Radiographs and Patient Clinical Covariates

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    This study considers the use of deep learning to diagnose osteoporosis from hip radiographs, and whether adding clinical data improves diagnostic performance over the image mode alone. For objective labeling, we collected a dataset containing 1131 images from patients who underwent both skeletal bone mineral density measurement and hip radiography at a single general hospital between 2014 and 2019. Osteoporosis was assessed from the hip radiographs using five convolutional neural network (CNN) models. We also investigated ensemble models with clinical covariates added to each CNN. The accuracy, precision, recall, specificity, negative predictive value (npv), F1 score, and area under the curve (AUC) score were calculated for each network. In the evaluation of the five CNN models using only hip radiographs, GoogleNet and EfficientNet b3 exhibited the best accuracy, precision, and specificity. Among the five ensemble models, EfficientNet b3 exhibited the best accuracy, recall, npv, F1 score, and AUC score when patient variables were included. The CNN models diagnosed osteoporosis from hip radiographs with high accuracy, and their performance improved further with the addition of clinical covariates from patient records

    Odontology & artificial intelligence

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    Neste trabalho avaliam-se os três fatores que fizeram da inteligência artificial uma tecnologia essencial hoje em dia, nomeadamente para a odontologia: o desempenho do computador, Big Data e avanços algorítmicos. Esta revisão da literatura avaliou todos os artigos publicados na PubMed até Abril de 2019 sobre inteligência artificial e odontologia. Ajudado com inteligência artificial, este artigo analisou 1511 artigos. Uma árvore de decisão (If/Then) foi executada para selecionar os artigos mais relevantes (217), e um algoritmo de cluster k-means para resumir e identificar oportunidades de inovação. O autor discute os artigos mais interessantes revistos e compara o que foi feito em inovação durante o International Dentistry Show, 2019 em Colónia. Concluiu, assim, de forma crítica que há uma lacuna entre tecnologia e aplicação clínica desta, sendo que a inteligência artificial fornecida pela indústria de hoje pode ser considerada um atraso para o clínico de amanhã, indicando-se um possível rumo para a aplicação clínica da inteligência artificial.There are three factors that have made artificial intelligence (AI) an essential technology today: the computer performance, Big Data and algorithmic advances. This study reviews the literature on AI and Odontology based on articles retrieved from PubMed. With the help of AI, this article analyses a large number of articles (a total of 1511). A decision tree (If/Then) was run to select the 217 most relevant articles-. Ak-means cluster algorithm was then used to summarize and identify innovation opportunities. The author discusses the most interesting articles on AI research and compares them to the innovation presented during the International Dentistry Show 2019 in Cologne. Three technologies available now are evaluated and three suggested options are been developed. The author concludes that AI provided by the industry today is a hold-up for the praticioner of tomorrow. The author gives his opinion on how to use AI for the profit of patients
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