Scientists from South Ural State University, in collaboration with foreign colleagues, have proposed a new model for the classification of MRI images based on deep belief network, which will help to detect malignant brain tumors faster and more accurately. The research study was published in the high-ranked Journal of Big Data, indexed in the scientometric Scopus database.
Deep learning of neural networks for diagnostic accuracy of brain tumors
Glioblastoma (GBM) is a stage 4 malignant brain tumor in which a large proportion of tumor cells reproducing at any moment. Such tumors are life-threatening and can lead to partial or complete mental and physical disability.
Glioblastoma brain tumor
The study was carried out by an international group of scientists from Indian universities and South Ural State University. Senior researcher of the Department of Computer Science of the School of Electronic Engineering and Computer Science, post-doc Kumar Sachin along with Ph.D., Associate Professor Mikhail Tsymbler developed methods for computer analysis of MRI images (magnetic resonance imaging) to detect glioblastoma tumors based on artificial deep belief network.
Artificial neural network (ANN) is one of the powerful approaches in machine learning which are able to handle large amounts of data with desirable accuracy. Deep learning approaches are able to automatically extract the features from the large data sets, however the correctness of the extracted features are not guaranteed because a corresponding mathematical verification procedure has not yet been developed.
“In this study, we have proposed a classification model using hybrid deep belief networks (DBN) to classify magnetic resonance imaging (MRI) for glioblastoma tumor. We proposed framework for image classification in three stages. The first stage performs the data preprocessing that consists of feature extraction using discrete wavelet transform (a function that allows you to analyze the frequency of data), vectorization and construction of additional features for processing. The second stage deals with dimensionality reduction of the images using principal component analysis and provides reduced dimensional feature vectors for smooth image classification. Third stage consists of a stack of Restricted Boltzmann machines that form a deep belief network with hidden layers,” Kumar Sachin explains.
Post-doc, Senior researcher of the Department of Computer Science Kumar Sachin
Deep belief network often requires a large number of hidden layers that consists of large number of neurons to learn the best features from the raw image data. Hence, computational and space complexity is high and requires a lot of training time. The proposed approach combines discrete wavelet transform with deep belief network to improve the efficiency of existing deep belief network model. The results are validated using several statistical parameters. Statistical validation verifies that the combination of discrete wavelet transform and deep belief network outperformed the other classifiers in terms of training time, space complexity and classification accuracy.
The neural network will help doctors
The methods and approaches proposed in the study can be applied to develop automated systems for diagnosing and detecting cancerous tumors and other cell lesions using MRI images.
“Medical science is equipped with advanced devices and technology. MRI machines are able to capture high contrast images of the brain and other parts of the body. These MRI scans are very useful to diagnose and detect tumors and other defected cells. However, sufficient knowledge and experience is desirable in order to read and understand these MRI scans. Sometimes, unavailability of such trained people may delay the diagnosis process. Therefore, in order to automate the process, a classification model can be developed using machine learning methods,” Mikhail Tsymbler says.
The study can be expanded in the direction of increasing the efficiency of the classification model when working with a large number of MRI images, which include templates with occlusion. Occlusion generally indicates a blockage of blood vessels in the brain and requires special attention for accurate diagnosis. This study did not consider the application of the developed model for tumors with blood vessel occlusion; therefore the application of deep learning methods to these data is an interesting direction for future research.
SUSU is a member of the 5-100 Project intended to increase the competitiveness of Russian universities among the world's leading research and educational centers.
Research in the field of the Smart Industry is one of the three strategic directions for the development of scientific and educational activities at South Ural State University, along with ecology and materials science.