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  1. Article ; Online: Nuclei instance segmentation from histopathology images using Bayesian dropout based deep learning.

    Gudhe, Naga Raju / Kosma, Veli-Matti / Behravan, Hamid / Mannermaa, Arto

    BMC medical imaging

    2023  Volume 23, Issue 1, Page(s) 162

    Abstract: Background: The deterministic deep learning models have achieved state-of-the-art performance in various medical image analysis tasks, including nuclei segmentation from histopathology images. The deterministic models focus on improving the model ... ...

    Abstract Background: The deterministic deep learning models have achieved state-of-the-art performance in various medical image analysis tasks, including nuclei segmentation from histopathology images. The deterministic models focus on improving the model prediction accuracy without assessing the confidence in the predictions.
    Methods: We propose a semantic segmentation model using Bayesian representation to segment nuclei from the histopathology images and to further quantify the epistemic uncertainty. We employ Bayesian approximation with Monte-Carlo (MC) dropout during the inference time to estimate the model's prediction uncertainty.
    Results: We evaluate the performance of the proposed approach on the PanNuke dataset, which consists of 312 visual fields from 19 organ types. We compare the nuclei segmentation accuracy of our approach with that of a fully convolutional neural network, U-Net, SegNet, and the state-of-the-art Hover-net. We use F1-score and intersection over union (IoU) as the evaluation metrics. The proposed approach achieves a mean F1-score of 0.893 ± 0.008 and an IoU value of 0.868 ± 0.003 on the test set of the PanNuke dataset. These results outperform the Hover-net, which has a mean F1-score of 0.871 ± 0.010 and an IoU value of 0.840 ± 0.032.
    Conclusions: The proposed approach, which incorporates Bayesian representation and Monte-Carlo dropout, demonstrates superior performance in segmenting nuclei from histopathology images compared to existing models such as U-Net, SegNet, and Hover-net. By considering the epistemic uncertainty, our model provides a more reliable estimation of the prediction confidence. These findings highlight the potential of Bayesian deep learning for improving medical image analysis tasks and can contribute to the development of more accurate and reliable computer-aided diagnostic systems.
    MeSH term(s) Humans ; Deep Learning ; Image Processing, Computer-Assisted/methods ; Bayes Theorem ; Neural Networks, Computer ; Cell Nucleus
    Language English
    Publishing date 2023-10-19
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2061975-3
    ISSN 1471-2342 ; 1471-2342
    ISSN (online) 1471-2342
    ISSN 1471-2342
    DOI 10.1186/s12880-023-01121-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Chemical and Spectroscopic Characterization of Humic Acids Extracted from Filter Cake using Different Basic Solutions

    Behravan, Hamid Reza / Voroney, Paul / Khorassani, Reza / Fotovat, Amir / Moezei, Abdol Amir / Taghavi, Mehdi

    Sugar tech. 2020 Apr., v. 22, no. 2

    2020  

    Abstract: Filter cake is a valuable by-product generated during the process of making sugar from sugarcane in factories. The purpose of this experiment was to study the effect of different basic solutions on humic acid extraction rate. Chemical and spectroscopic ... ...

    Abstract Filter cake is a valuable by-product generated during the process of making sugar from sugarcane in factories. The purpose of this experiment was to study the effect of different basic solutions on humic acid extraction rate. Chemical and spectroscopic characterization of humic acids extracted from filter cake has also been investigated. In this research, extraction and chemistry of humic acid have been studied in two separate experiments. In the first experiment, humic acid was taken from filter cake using the IHSS reference method in three concentrations (0.5 M, 1 M and 2 M) of KOH and two preparation liquids (water and vinasses) in the laboratory of the School of Environmental Sciences at the University of Guelph. Changes in the extraction rate of humic acid with type and concentration of base solution also were studied. In the second experiment, Fourier transform infrared (FTIR) and 13C NMR were used to examine the chemistry of humic acid extracted from filter cake by 0.5 M KOH solutions (prepared using distilled water and vinasse). The results indicate that the highest extraction rate of humic acid was obtained when the 2 M KOH made from vinasse solution was used. Elemental analysis results, FTIR and NMR analyses as well as the E4/E6 ratio showed that all samples of extracted humic acid had similar chemical characteristics compared to the reference humic acid.
    Keywords Fourier transform infrared spectroscopy ; carbon ; factories ; filter cake ; humic acids ; nuclear magnetic resonance spectroscopy ; physicochemical properties ; potassium hydroxide ; spectral analysis ; stable isotopes ; sugarcane ; sugars ; vinasse
    Language English
    Dates of publication 2020-04
    Size p. 311-318.
    Publishing place Springer India
    Document type Article
    ZDB-ID 2433394-3
    ISSN 0974-0740 ; 0972-1525
    ISSN (online) 0974-0740
    ISSN 0972-1525
    DOI 10.1007/s12355-019-00770-5
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: Area-based breast percentage density estimation in mammograms using weight-adaptive multitask learning.

    Gudhe, Naga Raju / Behravan, Hamid / Sudah, Mazen / Okuma, Hidemi / Vanninen, Ritva / Kosma, Veli-Matti / Mannermaa, Arto

    Scientific reports

    2022  Volume 12, Issue 1, Page(s) 12060

    Abstract: Breast density, which is a measure of the relative amount of fibroglandular tissue within the breast area, is one of the most important breast cancer risk factors. Accurate segmentation of fibroglandular tissues and breast area is crucial for computing ... ...

    Abstract Breast density, which is a measure of the relative amount of fibroglandular tissue within the breast area, is one of the most important breast cancer risk factors. Accurate segmentation of fibroglandular tissues and breast area is crucial for computing the breast density. Semiautomatic and fully automatic computer-aided design tools have been developed to estimate the percentage of breast density in mammograms. However, the available approaches are usually limited to specific mammogram views and are inadequate for complete delineation of the pectoral muscle. These tools also perform poorly in cases of data variability and often require an experienced radiologist to adjust the segmentation threshold for fibroglandular tissue within the breast area. This study proposes a new deep learning architecture that automatically estimates the area-based breast percentage density from mammograms using a weight-adaptive multitask learning approach. The proposed approach simultaneously segments the breast and dense tissues and further estimates the breast percentage density. We evaluate the performance of the proposed model in both segmentation and density estimation on an independent evaluation set of 7500 craniocaudal and mediolateral oblique-view mammograms from Kuopio University Hospital, Finland. The proposed multitask segmentation approach outperforms and achieves average relative improvements of 2.88% and 9.78% in terms of F-score compared to the multitask U-net and a fully convolutional neural network, respectively. The estimated breast density values using our approach strongly correlate with radiologists' assessments with a Pearson's correlation of [Formula: see text] (95% confidence interval [0.89, 0.91]). We conclude that our approach greatly improves the segmentation accuracy of the breast area and dense tissues; thus, it can play a vital role in accurately computing the breast density. Our density estimation model considerably reduces the time and effort needed to estimate density values from mammograms by radiologists and therefore, decreases inter- and intra-reader variability.
    MeSH term(s) Breast/diagnostic imaging ; Breast Density ; Breast Neoplasms/diagnostic imaging ; Female ; Humans ; Image Processing, Computer-Assisted ; Mammography ; Neural Networks, Computer
    Language English
    Publishing date 2022-07-14
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-022-16141-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Predicting breast cancer risk using interacting genetic and demographic factors and machine learning.

    Behravan, Hamid / Hartikainen, Jaana M / Tengström, Maria / Kosma, Veli-Matti / Mannermaa, Arto

    Scientific reports

    2020  Volume 10, Issue 1, Page(s) 11044

    Abstract: Breast cancer (BC) is a multifactorial disease and the most common cancer in women worldwide. We describe a machine learning approach to identify a combination of interacting genetic variants (SNPs) and demographic risk factors for BC, especially factors ...

    Abstract Breast cancer (BC) is a multifactorial disease and the most common cancer in women worldwide. We describe a machine learning approach to identify a combination of interacting genetic variants (SNPs) and demographic risk factors for BC, especially factors related to both familial history (Group 1) and oestrogen metabolism (Group 2), for predicting BC risk. This approach identifies the best combinations of interacting genetic and demographic risk factors that yield the highest BC risk prediction accuracy. In tests on the Kuopio Breast Cancer Project (KBCP) dataset, our approach achieves a mean average precision (mAP) of 77.78 in predicting BC risk by using interacting genetic and Group 1 features, which is better than the mAPs of 74.19 and 73.65 achieved using only Group 1 features and interacting SNPs, respectively. Similarly, using interacting genetic and Group 2 features yields a mAP of 78.00, which outperforms the system based on only Group 2 features, which has a mAP of 72.57. Furthermore, the gene interaction maps built from genes associated with SNPs that interact with demographic risk factors indicate important BC-related biological entities, such as angiogenesis, apoptosis and oestrogen-related networks. The results also show that demographic risk factors are individually more important than genetic variants in predicting BC risk.
    MeSH term(s) Algorithms ; Breast Neoplasms/etiology ; Breast Neoplasms/genetics ; Databases, Factual ; Databases, Genetic ; Demography ; Epistasis, Genetic ; Female ; Genetic Predisposition to Disease ; Humans ; Machine Learning ; Polymorphism, Single Nucleotide ; Risk Factors
    Language English
    Publishing date 2020-07-06
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-020-66907-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Multi-level dilated residual network for biomedical image segmentation.

    Gudhe, Naga Raju / Behravan, Hamid / Sudah, Mazen / Okuma, Hidemi / Vanninen, Ritva / Kosma, Veli-Matti / Mannermaa, Arto

    Scientific reports

    2021  Volume 11, Issue 1, Page(s) 14105

    Abstract: We propose a novel multi-level dilated residual neural network, an extension of the classical U-Net architecture, for biomedical image segmentation. U-Net is the most popular deep neural architecture for biomedical image segmentation, however, despite ... ...

    Abstract We propose a novel multi-level dilated residual neural network, an extension of the classical U-Net architecture, for biomedical image segmentation. U-Net is the most popular deep neural architecture for biomedical image segmentation, however, despite being state-of-the-art, the model has a few limitations. In this study, we suggest replacing convolutional blocks of the classical U-Net with multi-level dilated residual blocks, resulting in enhanced learning capability. We also propose to incorporate a non-linear multi-level residual blocks into skip connections to reduce the semantic gap and to restore the information lost when concatenating features from encoder to decoder units. We evaluate the proposed approach on five publicly available biomedical datasets with different imaging modalities, including electron microscopy, magnetic resonance imaging, histopathology, and dermoscopy, each with its own segmentation challenges. The proposed approach consistently outperforms the classical U-Net by 2%, 3%, 6%, 8%, and 14% relative improvements in dice coefficient, respectively for magnetic resonance imaging, dermoscopy, histopathology, cell nuclei microscopy, and electron microscopy modalities. The visual assessments of the segmentation results further show that the proposed approach is robust against outliers and preserves better continuity in boundaries compared to the classical U-Net and its variant, MultiResUNet.
    Language English
    Publishing date 2021-07-08
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-021-93169-w
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Machine learning identifies interacting genetic variants contributing to breast cancer risk: A case study in Finnish cases and controls.

    Behravan, Hamid / Hartikainen, Jaana M / Tengström, Maria / Pylkäs, Katri / Winqvist, Robert / Kosma, Veli-Matti / Mannermaa, Arto

    Scientific reports

    2018  Volume 8, Issue 1, Page(s) 13149

    Abstract: We propose an effective machine learning approach to identify group of interacting single nucleotide polymorphisms (SNPs), which contribute most to the breast cancer (BC) risk by assuming dependencies among BCAC iCOGS SNPs. We adopt a gradient tree ... ...

    Abstract We propose an effective machine learning approach to identify group of interacting single nucleotide polymorphisms (SNPs), which contribute most to the breast cancer (BC) risk by assuming dependencies among BCAC iCOGS SNPs. We adopt a gradient tree boosting method followed by an adaptive iterative SNP search to capture complex non-linear SNP-SNP interactions and consequently, obtain group of interacting SNPs with high BC risk-predictive potential. We also propose a support vector machine formed by the identified SNPs to classify BC cases and controls. Our approach achieves mean average precision (mAP) of 72.66, 67.24 and 69.25 in discriminating BC cases and controls in KBCP, OBCS and merged KBCP-OBCS sample sets, respectively. These results are better than the mAP of 70.08, 63.61 and 66.41 obtained by using a polygenic risk score model derived from 51 known BC-associated SNPs, respectively, in KBCP, OBCS and merged KBCP-OBCS sample sets. BC subtype analysis further reveals that the 200 identified KBCP SNPs from the proposed method performs favorably in classifying estrogen receptor positive (ER+) and negative (ER-) BC cases both in KBCP and OBCS data. Further, a biological analysis of the identified SNPs reveals genes related to important BC-related mechanisms, estrogen metabolism and apoptosis.
    MeSH term(s) Base Sequence ; Breast Neoplasms/diagnosis ; Breast Neoplasms/genetics ; Breast Neoplasms/metabolism ; Breast Neoplasms/pathology ; Case-Control Studies ; Estrogen Receptor alpha/genetics ; Estrogen Receptor alpha/metabolism ; Female ; Finland ; Gene Expression Regulation, Neoplastic ; Gene Regulatory Networks ; Genetic Predisposition to Disease ; Genome, Human ; Genome-Wide Association Study ; Humans ; Polymorphism, Single Nucleotide ; Prognosis ; Protein Interaction Mapping ; Risk ; Support Vector Machine ; Ubiquitin-Protein Ligases/genetics ; Ubiquitin-Protein Ligases/metabolism
    Chemical Substances ESR1 protein, human ; Estrogen Receptor alpha ; Ubiquitin-Protein Ligases (EC 2.3.2.27) ; parkin protein (EC 2.3.2.27)
    Language English
    Publishing date 2018-09-03
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-018-31573-5
    Database MEDical Literature Analysis and Retrieval System OnLINE

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