Improving Mitosis Detection Via UNet-based Adversarial Domain Homogenizer

The effective localization of mitosis is a critical precursory task for deciding tumor prognosis and grade. Automated mitosis detection through deep learning-oriented image analysis often fails on unseen patient data due to inherent domain biases. This paper proposes a domain homogenizer for mitosis detection that attempts to alleviate domain differences in histology images via adversarial reconstruction of input images. The proposed homogenizer is based on a U-Net architecture and can effectively reduce domain differences commonly seen with histology imaging data. We demonstrate our domain homogenizer's effectiveness by observing the reduction in domain differences between the preprocessed images. Using this homogenizer, along with a subsequent retina-net object detector, we were able to outperform the baselines of the 2021 MIDOG challenge in terms of average precision of the detected mitotic figures

MoNuSAC2020:A Multi-Organ Nuclei Segmentation and Classification Challenge

Detecting various types of cells in and around the tumor matrix holds a special significance in characterizing the tumor micro-environment for cancer prognostication and research. Automating the tasks of detecting, segmenting, and classifying nuclei can free up the pathologists' time for higher value tasks and reduce errors due to fatigue and subjectivity. To encourage the computer vision research community to develop and test algorithms for these tasks, we prepared a large and diverse dataset of nucleus boundary annotations and class labels. The dataset has over 46,000 nuclei from 37 hospitals, 71 patients, four organs, and four nucleus types. We also organized a challenge around this dataset as a satellite event at the International Symposium on Biomedical Imaging (ISBI) in April 2020. The challenge saw a wide participation from across the world, and the top methods were able to match inter-human concordance for the challenge metric. In this paper, we summarize the dataset and the key findings of the challenge, including the commonalities and differences between the methods developed by various participants. We have released the MoNuSAC2020 dataset to the public

Adaptive filter design : An information theoretic learning approach

Adaptive _ltering has gained wide popularity in recent times in non stationary signal processing environment. Supervised adaptive _ltering requires the use of a reference signal and an adaptive algorithm. The robustness of adaptive algorithms are put to real test while operating in real time environments contaminated with practical alpha stable noise. The conventional algorithms tend to loose stability easily, resulting in improper or diverging learning results. The use of _nite order statistics is cited as the major reason for this behaviour. The information theory, a popular _eld in communication engineering is gaining wide acceptance in many conventional signal processing problems. This thesis tries to exploit the merits of correntropy, which is related to correlation and entropy, and use the same in adaptive _ltering by analysing some practical systems namely noise cancellers, generalised sidelobe cancellers and active noise control\ systems. Practical implementation on a standard DSP processor has been done to see the behaviour of noise canceller in real time. Rigorous analysis has been carried out to _nd out the merits of such systems supplemented by information theoretic learning against conventional second order statistics based learning.by Nikhil Cherian KurianM.Tech

Time frequency analysis: a sparse S transform approach

by Kashyap Patel, Nikhil C. Kurian and Nithin V. Georg

Robust active noise control: an information theoretic learning approach

by Nikhil Cherian Kurian, Kashyap Patel and Nithin V. Georg

Efficient quality control of whole slide pathology images with human-in-the-loop training

Histopathology whole slide images (WSIs) are being widely used to develop deep learning-based diagnostic solutions, especially for precision oncology. Most of these diagnostic softwares are vulnerable to biases and impurities in the training and test data which can lead to inaccurate diagnoses. For instance, WSIs contain multiple types of tissue regions, at least some of which might not be relevant to the diagnosis. We introduce HistoROI, a robust yet lightweight deep learning-based classifier to segregate WSI into 6 broad tissue regions—epithelium, stroma, lymphocytes, adipose, artifacts, and miscellaneous. HistoROI is trained using a novel human in-the-loop and active learning paradigm that ensures variations in training data for labeling efficient generalization. HistoROI consistently performs well across multiple organs, despite being trained on only a single dataset, demonstrating strong generalization. Further, we have examined the utility of HistoROI in improving the performance of downstream deep learning-based tasks using the CAMELYON breast cancer lymph node and TCGA lung cancer datasets. For the former dataset, the area under the receiver operating characteristic curve (AUC) for metastasis versus normal tissue of a neural network trained using weakly supervised learning increased from 0.88 to 0.92 by filtering the data using HistoROI. Similarly, the AUC increased from 0.88 to 0.93 for the classification between adenocarcinoma and squamous cell carcinoma on the lung cancer dataset. We also found that the performance of the HistoROI improves upon HistoQC for artifact detection on a test dataset of 93 annotated WSIs. The limitations of the proposed model are analyzed, and potential extensions are also discussed