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Rundo L, Tangherloni A, Cazzaniga P, Nobile MS, Russo G, Gilardi MC, Vitabile S, Mauri G, Besozzi D, Militello C. A novel framework for MR image segmentation and quantification by using MedGA. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2019; 176:159-172. [PMID: 31200903 DOI: 10.1016/j.cmpb.2019.04.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 04/14/2019] [Accepted: 04/16/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND AND OBJECTIVES Image segmentation represents one of the most challenging issues in medical image analysis to distinguish among different adjacent tissues in a body part. In this context, appropriate image pre-processing tools can improve the result accuracy achieved by computer-assisted segmentation methods. Taking into consideration images with a bimodal intensity distribution, image binarization can be used to classify the input pictorial data into two classes, given a threshold intensity value. Unfortunately, adaptive thresholding techniques for two-class segmentation work properly only for images characterized by bimodal histograms. We aim at overcoming these limitations and automatically determining a suitable optimal threshold for bimodal Magnetic Resonance (MR) images, by designing an intelligent image analysis framework tailored to effectively assist the physicians during their decision-making tasks. METHODS In this work, we present a novel evolutionary framework for image enhancement, automatic global thresholding, and segmentation, which is here applied to different clinical scenarios involving bimodal MR image analysis: (i) uterine fibroid segmentation in MR guided Focused Ultrasound Surgery, and (ii) brain metastatic cancer segmentation in neuro-radiosurgery therapy. Our framework exploits MedGA as a pre-processing stage. MedGA is an image enhancement method based on Genetic Algorithms that improves the threshold selection, obtained by the efficient Iterative Optimal Threshold Selection algorithm, between the underlying sub-distributions in a nearly bimodal histogram. RESULTS The results achieved by the proposed evolutionary framework were quantitatively evaluated, showing that the use of MedGA as a pre-processing stage outperforms the conventional image enhancement methods (i.e., histogram equalization, bi-histogram equalization, Gamma transformation, and sigmoid transformation), in terms of both MR image enhancement and segmentation evaluation metrics. CONCLUSIONS Thanks to this framework, MR image segmentation accuracy is considerably increased, allowing for measurement repeatability in clinical workflows. The proposed computational solution could be well-suited for other clinical contexts requiring MR image analysis and segmentation, aiming at providing useful insights for differential diagnosis and prognosis.
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Affiliation(s)
- Leonardo Rundo
- Department of Informatics, Systems and Communication, University of Milano-Bicocca, Milan, Italy; Institute of Molecular Bioimaging and Physiology, Italian National Research Council, Cefalù, PA, Italy; Department of Radiology, University of Cambridge, Cambridge, UK; Cancer Research UK Cambridge Centre, Cambridge, UK.
| | - Andrea Tangherloni
- Department of Informatics, Systems and Communication, University of Milano-Bicocca, Milan, Italy; Department of Haematology, University of Cambridge, Cambridge, UK; Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK.
| | - Paolo Cazzaniga
- Department of Human and Social Sciences, University of Bergamo, Bergamo, Italy; SYSBIO.IT Centre of Systems Biology, Milan, Italy.
| | - Marco S Nobile
- Department of Informatics, Systems and Communication, University of Milano-Bicocca, Milan, Italy; SYSBIO.IT Centre of Systems Biology, Milan, Italy.
| | - Giorgio Russo
- Institute of Molecular Bioimaging and Physiology, Italian National Research Council, Cefalù, PA, Italy.
| | - Maria Carla Gilardi
- Institute of Molecular Bioimaging and Physiology, Italian National Research Council, Cefalù, PA, Italy.
| | - Salvatore Vitabile
- Department of Biomedicine, Neuroscience and Advanced Diagnostics, University of Palermo, Palermo, Italy.
| | - Giancarlo Mauri
- Department of Informatics, Systems and Communication, University of Milano-Bicocca, Milan, Italy; SYSBIO.IT Centre of Systems Biology, Milan, Italy.
| | - Daniela Besozzi
- Department of Informatics, Systems and Communication, University of Milano-Bicocca, Milan, Italy.
| | - Carmelo Militello
- Institute of Molecular Bioimaging and Physiology, Italian National Research Council, Cefalù, PA, Italy.
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Pashazadeh A, Navimipour NJ. Big data handling mechanisms in the healthcare applications: A comprehensive and systematic literature review. J Biomed Inform 2018; 82:47-62. [PMID: 29655946 DOI: 10.1016/j.jbi.2018.03.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 11/19/2017] [Accepted: 03/23/2018] [Indexed: 01/08/2023]
Abstract
Healthcare provides many services such as diagnosing, treatment, prevention of diseases, illnesses, injuries, and other physical and mental disorders. Large-scale distributed data processing applications in healthcare as a basic concept operates on large amounts of data. Therefore, big data application functions are the main part of healthcare operations, but there was not any comprehensive and systematic survey about studying and evaluating the important techniques in this field. Therefore, this paper aims at providing the comprehensive, detailed, and systematic study of the state-of-the-art mechanisms in the big data related to healthcare applications in five categories, including machine learning, cloud-based, heuristic-based, agent-based, and hybrid mechanisms. Also, this paper displayed a systematic literature review (SLR) of the big data applications in the healthcare literature up to the end of 2016. Initially, 205 papers were identified, but a paper selection process reduced the number of papers to 29 important studies.
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Affiliation(s)
- Asma Pashazadeh
- Department of Computer Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran
| | - Nima Jafari Navimipour
- Department of Computer Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran.
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Villaverde AF, Bongard S, Mauch K, Müller D, Balsa-Canto E, Schmid J, Banga JR. A consensus approach for estimating the predictive accuracy of dynamic models in biology. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2015; 119:17-28. [PMID: 25716416 DOI: 10.1016/j.cmpb.2015.02.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 12/19/2014] [Accepted: 02/02/2015] [Indexed: 06/04/2023]
Abstract
Mathematical models that predict the complex dynamic behaviour of cellular networks are fundamental in systems biology, and provide an important basis for biomedical and biotechnological applications. However, obtaining reliable predictions from large-scale dynamic models is commonly a challenging task due to lack of identifiability. The present work addresses this challenge by presenting a methodology for obtaining high-confidence predictions from dynamic models using time-series data. First, to preserve the complex behaviour of the network while reducing the number of estimated parameters, model parameters are combined in sets of meta-parameters, which are obtained from correlations between biochemical reaction rates and between concentrations of the chemical species. Next, an ensemble of models with different parameterizations is constructed and calibrated. Finally, the ensemble is used for assessing the reliability of model predictions by defining a measure of convergence of model outputs (consensus) that is used as an indicator of confidence. We report results of computational tests carried out on a metabolic model of Chinese Hamster Ovary (CHO) cells, which are used for recombinant protein production. Using noisy simulated data, we find that the aggregated ensemble predictions are on average more accurate than the predictions of individual ensemble models. Furthermore, ensemble predictions with high consensus are statistically more accurate than ensemble predictions with large variance. The procedure provides quantitative estimates of the confidence in model predictions and enables the analysis of sufficiently complex networks as required for practical applications.
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Affiliation(s)
| | - Sophia Bongard
- Insilico Biotechnology AG, Meitnerstraße 8, 70563 Stuttgart, Germany.
| | - Klaus Mauch
- Insilico Biotechnology AG, Meitnerstraße 8, 70563 Stuttgart, Germany.
| | - Dirk Müller
- Insilico Biotechnology AG, Meitnerstraße 8, 70563 Stuttgart, Germany.
| | - Eva Balsa-Canto
- Bioprocess Engineering Group, IIM-CSIC, Eduardo Cabello 6, 36208 Vigo, Spain.
| | - Joachim Schmid
- Insilico Biotechnology AG, Meitnerstraße 8, 70563 Stuttgart, Germany.
| | - Julio R Banga
- Bioprocess Engineering Group, IIM-CSIC, Eduardo Cabello 6, 36208 Vigo, Spain.
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Liu F, Vilaça P, Rocha I, Rocha M. Development and application of efficient pathway enumeration algorithms for metabolic engineering applications. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2015; 118:134-146. [PMID: 25580014 DOI: 10.1016/j.cmpb.2014.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/31/2014] [Accepted: 11/26/2014] [Indexed: 06/04/2023]
Abstract
Metabolic Engineering (ME) aims to design microbial cell factories towards the production of valuable compounds. In this endeavor, one important task relates to the search for the most suitable heterologous pathway(s) to add to the selected host. Different algorithms have been developed in the past towards this goal, following distinct approaches spanning constraint-based modeling, graph-based methods and knowledge-based systems based on chemical rules. While some of these methods search for pathways optimizing specific objective functions, here the focus will be on methods that address the enumeration of pathways that are able to convert a set of source compounds into desired targets and their posterior evaluation according to different criteria. Two pathway enumeration algorithms based on (hyper)graph-based representations are selected as the most promising ones and are analyzed in more detail: the Solution Structure Generation and the Find Path algorithms. Their capabilities and limitations are evaluated when designing novel heterologous pathways, by applying these methods on three case studies of synthetic ME related to the production of non-native compounds in E. coli and S. cerevisiae: 1-butanol, curcumin and vanillin. Some targeted improvements are implemented, extending both methods to address limitations identified that impair their scalability, improving their ability to extract potential pathways over large-scale databases. In all case-studies, the algorithms were able to find already described pathways for the production of the target compounds, but also alternative pathways that can represent novel ME solutions after further evaluation.
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Affiliation(s)
- F Liu
- Centre for Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal
| | - P Vilaça
- Centre for Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; SilicoLife Lda., Rua do Canastreiro 15, 4715-387 Braga, Portugal
| | - I Rocha
- Centre for Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal
| | - M Rocha
- Centre for Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal.
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