Dehkharghanian, Taher

AbstractAn increasing number of machine learning applications are being developed and applied to digital pathology, including hematopathology. The goal of these modern computerized tools is often to support diagnostic workflows by extracting and summarizing information from multiple data sources, including digital images of human tissue. Hematopathology is inherently multimodal and can serve as an ideal case study for machine learning applications. However, hematopathology also poses unique challenges compared to other pathology subspecialities when applying machine learning approaches. By modeling the pathologist workflow and thinking process, machine learning algorithms may be designed to address practical and tangible problems in hematopathology. In this article, we discuss the current trends in machine learning in hematopathology. We review currently available machine learning enabled medical devices supporting hematopathology workflows. We then explore current machine learning research trends of the field with a focus on bone marrow cytology and histopathology, and how adoption of new machine learning tools may be enabled through the transition to digital pathology.

Abstract Appearing traces of bias in deep networks is a serious issue that can play a significant role in ethics and generalization. Recent studies report that the deep features extracted from the histopathology images of The Cancer Genome Atlas (TCGA), the largest publicly available archive of 11,000 patients covering 25 organs and 32 cancer subtypes, are surprisingly able to accurately classify the whole slide images (WSIs) based on their acquisition site. This is clear evidence that the utilized Deep Neural Networks (DNNs) unexpectedly detect the specific patterns of the source site rather than histomorphologic patterns, biased behaviour resulting in degraded generalization. This observation motivated us to propose a method to alleviate the destructive impact of hospital bias through a novel feature selection process. To this effect, we have proposed an evolutionary strategy select a small set of optimal features to not only accurately represent the histological patterns of tissue samples but also to eliminate the features leading to internal bias toward the institution. The performance of the proposed method has been assessed using the features extracted from TCGA images made available by NIH (National Institute of Health). The selected features extracted by a state-of-the-art network trained on TCGA images (i.e., the KimiaNet), considerably decreased the institutional bias. The proposed scheme is not limited to DNNs and/or specific types of biases; it can be employed to reduce various kinds of bias in a much more comprehensive range of data-driven feature extraction models. The conducted experiments, the external validation in specific, clearly demonstrate that the bias cannot be fully controlled just during training a model. Therefore, a feature selection for downstream tasks plays a crucial role in significantly reducing the bias.