Dissertations - M Tech (CS)

Permanent URI for this collectionhttp://164.52.219.250:4000/handle/10263/2147

These Dissertations were submitted in partial fulfilment of the requirements for the award of M TECH (Computer Science) Degree of Indian Statistical Institute

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    Few shot segmentation for COVID-19 infected lung CT slices
    (Indian Statistical Institute, Kolkata, 2022-07) Chatterjee, Soham
    The last 2 years have been adversely affected by the COVID-19 pandemic. Doctors usually detect Covid from CT slices from features such as ground glass, consolidation and pleural effusion. These features usually have complex contours, irregular shapes and rough boundaries. With increasing number of cases the workload on the radiologists have increased by leaps and bounds to analyze the lung CT scans for tracking the disease progression in the patient. Moreover manual analysis of the CT scans is also prone to human error. So automated segmentation of infected lung CT slices can help the doctors to diagnose the disease faster. With the advent of deep learning, various approaches have been built to tackle this problem of automated biomedical image segmentation. One such architecture is the U-Net by Ronnenberger et al. [14]. Various other approaches have been proposed which are all variations of the U-Net to achieve better segmentation performance. However, the U-Net and its variations suffer from high model complexity, due to which they easily overfit on limited labelled dataset which is a serious issue in medical image domain. To cater this problem of data scarcity, research in “few shot segmentation” has gained significant importance in the recent years. In this work, we have developed a deep neural network model called Few Shot Conditioner Segmenter Covid (FSCS-cov), an architecture to tackle the problem of segmenting different COVID- 19 lesions from limited number of COVID-19 infected lung CT slices using few - shot learning paradigm.
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    Deep Learning for Classification of COVID-19 Chest CT Scan
    (Indian Statistical Institute, Kolkata., 2021-07) Ghosh, Subhadip
    The latest threat to global health is COVID-19. It has a tremendous diffusion rate and to combat with this pandemic, large scale testing and diagnosis is required. RT-PCR is the most accurate screening for validating COVID19 infection, but it is highly dependent on swab technique and needs time and resources. Thus, we need to find an alternative way to predict COVID19. Many researchers already conclude that COVID-19 is very related to Pneumonia and lungs feature of COVID is related to that of Pneumonia. There is ongoing research to detect Pneumonia [13] from Chest CT scans. Lung segmentation can help us to detect pulmonary abnormalities[10]. In this article first we try to segment lungs from chest CT scan and investigate the problems we face for COVID cases in deep learning architectures for lung segmentation. We propose an classical image processing algorithm to detect Lung from chest CT. As already mentioned that CNN is a great architecture to classify images, we are going to use a deep CNN model for lung classification. Covid is a new disease and we have to move faster to detect it. Hence, we are going to use transfer learning approach and use knowledge of pneumonia detection to classify COVID-19. In deep learning weight initialization for deep neural network is a major factor and can lead us to very different performance. In this article we are going to propose an weight initialization technique for transfer learning that can use not only the information about the architecture but also the information of the new class with respect to other known classes.