Computer aided diagnosis system using dermatoscopical image

Computer Aided Diagnosis (CAD) systems for melanoma detection aim to mirror the expert dermatologist decision when watching a dermoscopic or clinical image. Computer Vision techniques, which can be based on expert knowledge or not, are used to characterize the lesion image. This information is delivered to a machine learning algorithm, which gives a diagnosis suggestion as an output. This research is included into this field, and addresses the objective of implementing a complete CAD system using ‘state of the art’ descriptors and dermoscopy images as input. Some of them are based on expert knowledge and others are typical in a wide variety of problems. Images are initially transformed into oRGB, a perceptual color space, looking for both enhancing the information that images provide and giving human perception to machine algorithms. Feature selection is also performed to find features that really contribute to discriminate between benign and malignant pigmented skin lesions (PSL). The problem of robust model fitting versus statistically significant system evaluation is critical when working with small datasets, which is indeed the case. This topic is not generally considered in works related to PSLs. Consequently, a method that optimizes the compromise between these two goals is proposed, giving non-overfitted models and statistically significant measures of performance. In this manner, different systems can be compared in a fairer way. A database which enjoys wide international acceptance among dermatologists is used for the experiments.Ingeniería de Sistemas Audiovisuale

Using adaptive thresholding and skewness correction to detect gray areas in melanoma \u3ci\u3ein situ\u3c/i\u3e images

The incidence of melanoma in situ (MIS) is growing significantly. Detection at the MIS stage provides the highest cure rate for melanoma, but reliable detection of MIS with dermoscopy alone is not yet possible. Adjunct dermoscopic instrumentation using digital image analysis may allow more accurate detection of MIS. Gray areas are a critical component of MIS diagnosis, but automatic detection of these areas remains difficult because similar gray areas are also found in benign lesions. This paper proposes a novel adaptive thresholding technique for automatically detecting gray areas specific to MIS. The proposed model uses only MIS dermoscopic images to precisely determine gray area characteristics specific to MIS. To this aim, statistical histogram analysis is employed in multiple color spaces. It is demonstrated that skew deviation due to an asymmetric histogram distorts the color detection process. We introduce a skew estimation technique that enables histogram asymmetry correction facilitating improved adaptive thresholding results. These histogram statistical methods may be extended to detect any local image area defined by histograms --Abstract, page iv

Automatic Skin Cancer Detection in Dermoscopy Images Based on Ensemble Lightweight Deep Learning Network

The complex detection background and lesion features make the automatic detection of dermoscopy image lesions face many challenges. The previous solutions mainly focus on using larger and more complex models to improve the accuracy of detection, there is a lack of research on significant intra-class differences and inter-class similarity of lesion features. At the same time, the larger model size also brings challenges to further algorithm application; In this paper, we proposed a lightweight skin cancer recognition model with feature discrimination based on fine-grained classification principle. The propose model includes two common feature extraction modules of lesion classification network and a feature discrimination network. Firstly, two sets of training samples (positive and negative sample pairs) are input into the feature extraction module (Lightweight CNN) of the recognition model. Then, two sets of feature vectors output from the feature extraction module are used to train the two classification networks and feature discrimination networks of the recognition model at the same time, and the model fusion strategy is applied to further improve the performance of the model, the proposed recognition method can extract more discriminative lesion features and improve the recognition performance of the model in a small amount of model parameters; In addition, based on the feature extraction module of the proposed recognition model, U-Net architecture, and migration training strategy, we build a lightweight semantic segmentation model of lesion area of dermoscopy image, which can achieve high precision lesion area segmentation end-to-end without complicated image preprocessing operation; The performance of our approach was appraised through widespread experiments comparative and feature visualization analysis, the outcome indicates that the proposed method has better performance than the start-of-the-art deep learning-based approach on the ISBI 2016 skin lesion analysis towards melanoma detection challenge dataset

Aprendizado profundo em triagem de melanoma

Orientadores: Eduardo Alves do Valle Junior, Lin Tzy LiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: De todos os cânceres de pele, melanoma representa apenas 1% dos casos, mas 75% das mortes. O prognóstico do melanoma é bom quando detectado cedo, mas deteriora rápido ao longo que a doença progride. Ferramentas automatizadas podem prover triagem mais rápida, ajudando médicos a focar em pacientes ou lesões de risco. As características da doença --- raridade, letalidade, rápida progressão, e diagnóstico sutil --- fazem a triagem de melanoma automática particularmente desafiadora. O objetivo deste trabalho é melhor compreender como Deep Learning pode ser utilizado --- mais precisamente, Redes Neurais Convolucionais --- para classificar corretamente imagens de lesões de pele. Para isso, este trabalho está dividido em duas linhas de pesquisa. Primeiro, o estudo está focado na transferibilidade de características das redes CNN pré-treinadas. O objetivo principal desse tópico é estudar como as características transferidas se comportam em diferentes esquemas, com o objetivo de gerar melhores características para a camada de decisão. Em um segundo tópico, esse estudo incidirá na melhoria das métricas de classificação, que é o objetivo geral. Sobre a transferibilidade das características, foram realizados experimentos para analisar a forma como os diferentes esquemas de transferência afetariam a Área sob a Curva ROC (AUC): treinar uma CNN a partir do zero; transferir o conhecimento de uma CNN pré-treinada com imagens gerais ou específicas; realizar uma transferência dupla, que é uma sequência de treinamento onde em um primeiro momento a rede é treinada com imagens gerais, em um segundo momento com as imagens específicas, e, finalmente, em um terceiro momento com as imagens de melanoma. A partir desses experimentos, aprendemos que a transferência de aprendizagem é uma boa prática, assim como é o ajuste fino. Os resultados também sugerem que modelos mais profundos conduzem a melhores resultados. Hipotetizamos que a transferência de aprendizagem de uma tarefa relacionada sob ponto de vista médico (no caso, a partir de um dataset de imagens de retinopatia) levaria a melhores resultados, especialmente no esquema de transferência dupla, mas os resultados mostraram o oposto, sugerindo que a adaptação de tarefas muito específicas representa desafios específicos. Sobre a melhoria das métricas, discute-se o pipeline vencedor utilizado no International Skin Imaging Collaboration (ISIC) Challenge 2017, alcançando o estado da arte na classificação de melanoma com 87.4% AUC. A solução é baseada em stacking/meta learning dos modelos Inception v4 e Resnet101, realizando fine tuning enquanto executa a aumentação de dados nos conjuntos de treino e teste. Também comparamos diferentes técnicas de segmentação --- multiplicação elemento a elemento da imagem da lesão de pele e sua máscara de segmentação, e utilizar a máscara de segmentação como quarto canal --- com uma rede treinada sem segmentação. A rede sem segmentação é a que obteve melhor desemepnho (96.0% AUC) contra a máscara de segmentação como quarto canal (94.5% AUC). Nós também disponibilizamos uma implementação de referência reprodutível com todo o código desenvolvido para as contribuições desta dissertaçãoAbstract: From all skin cancers, melanoma represents just 1% of cases, but 75% of deaths. Melanoma¿s prognosis is good when detected early, but deteriorates fast as the disease progresses. Automated tools may play an essential role in providing timely screening, helping doctors focus on patients or lesions at risk. However, due to the disease¿s characteristics --- rarity, lethality, fast progression, and diagnosis subtlety --- automated screening for melanoma is particularly challenging. The objective of this work is to understand better how can we use Deep Learning --- more precisely, Convolutional Neural Networks --- to correctly classify images of skin lesions. This work is divided into two lines of investigation to achieve the objective. First, the study is focused on the transferability of features from pretrained CNN networks. The primary objective of that thread is to study how the transferred features behave in different schemas, aiming at generating better features to the classifier layer. Second, this study will also improve the classification metrics, which is the overall objective of this line of research. On the transferability of features, we performed experiments to analyze how different transfer schemas would impact the overall Area Under the ROC Curve (AUC) training a CNN from scratch; transferring from pretrained CNN on general and specific image databases; performing a double transfer, in a sequence from general to specific and finally melanoma databases. From those experiments, we learned that transfer learning is a good practice, as is fine tuning. The results also suggest that deeper models lead to better results. We expected that transfer learning from a related task (in the case, from a retinopathy image database) would lead to better outcomes, but results showed the opposite, suggesting that adaptation from particular tasks poses specific challenges. On the improvement of metrics, we discussed the winner pipeline used in the International Skin Imaging Collaboration (ISIC) Challenge 2017, reaching state-of-the-art results on melanoma classification with 87.4% AUC. The solution is based on the stacking/meta-learning from Inception v4 and Resnet101 models, fine tuning them while performing data augmentation on the train and test sets. Also, we compare different segmentation techniques - elementwise multiplication of the skin lesion image and its mask, and input the segmentation mask as a fourth channel - with a network trained without segmentation. The network with no segmentation is the one who performs better (96.0% AUC) against segmentation mask as a fourth channel (94.5% AUC). We made available a reproducible reference implementation with all developed source code for the contributions of this thesisMestradoEngenharia de ComputaçãoMestre em Engenharia Elétrica133530/2016-7CNP

Dermatitis Atopic and Psoriasis Skin Disease Classification by using Convolutional Neural Network

Skin is the one of the body parts that play a large role in human physical body. There are so many functions of the skin such as offering protection against fungal infection, bacteria, allergy, viruses and controls the temperature of the body. But, the reported shown that the skin disease is the most common disease in humans among all age groups and a significant root of infection. The diagnosis of skin diseases involves several tests. Due to this, the diagnosis process is seen to be intensely laborious, time-consuming and requires an extensive understanding aspecially for the skin disease that have similar symptoms. Two skin diseases that have similar symptoms and most misdiagnosed are atopic dermatitis and psoriasis. Convolutional Neural Network for image processing and classifying have been developed for more accurate classification of skin diseases with different architectures. However, the accuracy in determining skin lesions using CNNs is on the average level. The factors that affect the accuracy result of a CNN is the depth where gradients vanished as the network goes deeper. Another factor is the variance in the training set which means the need of the large size of training set. Hence, in this study we tried 10 CNN architecture to get the best result for classifying dermatitis atopic and psoriasis. These are VGG 16, VGG 19, ResNet 50, ResNet 101, MobileNet, MobileNet V2, DenseNet 121, DenseNet 201, Inception and Xception. Experimental result shown that the inception V3 architecture give the best result with accuracy for data testing 84%, accuracy for unseen data 82% and confusion matrix with True positive obtained is 248, True Negative is 61, False positive is 54 and False Negative 298

Dermatitis Atopic and Psoriasis Skin Disease Classification by using Convolutional Neural Network

Skin is the one of the body parts that play a large role in human physical body. There are so many functions of the skin such as offering protection against fungal infection, bacteria, allergy, viruses and controls the temperature of the body. But, the reported shown that the skin disease is the most common disease in humans among all age groups and a significant root of infection. The diagnosis of skin diseases involves several tests. Due to this, the diagnosis process is seen to be intensely laborious, time-consuming and requires an extensive understanding aspecially for the skin disease that have similar symptoms. Two skin diseases that have similar symptoms and most misdiagnosed are atopic dermatitis and psoriasis. Convolutional Neural Network for image processing and classifying have been developed for more accurate classification of skin diseases with different architectures. However, the accuracy in determining skin lesions using CNNs is on the average level. The factors that affect the accuracy result of a CNN is the depth where gradients vanished as the network goes deeper. Another factor is the variance in the training set which means the need of the large size of training set. Hence, in this study we tried 10 CNN architecture to get the best result for classifying dermatitis atopic and psoriasis. These are VGG 16, VGG 19, ResNet 50, ResNet 101, MobileNet, MobileNet V2, DenseNet 121, DenseNet 201, Inception and Xception. Experimental result shown that the inception V3 architecture give the best result with accuracy for data testing 84%, accuracy for unseen data 82% and confusion matrix with True positive obtained is 248, True Negative is 61, False positive is 54 and False Negative 298

Artificial Intelligence in Cutaneous Oncology

Skin cancer, previously known to be a common disease in Western countries, is becoming more common in Asian countries. Skin cancer differs from other carcinomas in that it is visible to our eyes. Although skin biopsy is essential for the diagnosis of skin cancer, decisions regarding whether or not to conduct a biopsy are made by an experienced dermatologist. From this perspective, it is easy to obtain and store photos using a smartphone, and artificial intelligence technologies developed to analyze these photos can represent a useful tool to complement the dermatologist's knowledge. In addition, the universal use of dermoscopy, which allows for non-invasive inspection of the upper dermal level of skin lesions with a usual 10-fold magnification, adds to the image storage and analysis techniques, foreshadowing breakthroughs in skin cancer diagnosis. Current problems include the inaccuracy of the available technology and resulting legal liabilities. This paper presents a comprehensive review of the clinical applications of artificial intelligence and a discussion on how it can be implemented in the field of cutaneous oncology.ope