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1.
Radiology ; 305(2): 454-465, 2022 11.
Article in English | MEDLINE | ID: covidwho-1950321

ABSTRACT

Background Developing deep learning models for radiology requires large data sets and substantial computational resources. Data set size limitations can be further exacerbated by distribution shifts, such as rapid changes in patient populations and standard of care during the COVID-19 pandemic. A common partial mitigation is transfer learning by pretraining a "generic network" on a large nonmedical data set and then fine-tuning on a task-specific radiology data set. Purpose To reduce data set size requirements for chest radiography deep learning models by using an advanced machine learning approach (supervised contrastive [SupCon] learning) to generate chest radiography networks. Materials and Methods SupCon helped generate chest radiography networks from 821 544 chest radiographs from India and the United States. The chest radiography networks were used as a starting point for further machine learning model development for 10 prediction tasks (eg, airspace opacity, fracture, tuberculosis, and COVID-19 outcomes) by using five data sets comprising 684 955 chest radiographs from India, the United States, and China. Three model development setups were tested (linear classifier, nonlinear classifier, and fine-tuning the full network) with different data set sizes from eight to 85. Results Across a majority of tasks, compared with transfer learning from a nonmedical data set, SupCon reduced label requirements up to 688-fold and improved the area under the receiver operating characteristic curve (AUC) at matching data set sizes. At the extreme low-data regimen, training small nonlinear models by using only 45 chest radiographs yielded an AUC of 0.95 (noninferior to radiologist performance) in classifying microbiology-confirmed tuberculosis in external validation. At a more moderate data regimen, training small nonlinear models by using only 528 chest radiographs yielded an AUC of 0.75 in predicting severe COVID-19 outcomes. Conclusion Supervised contrastive learning enabled performance comparable to state-of-the-art deep learning models in multiple clinical tasks by using as few as 45 images and is a promising method for predictive modeling with use of small data sets and for predicting outcomes in shifting patient populations. © RSNA, 2022 Online supplemental material is available for this article.


Subject(s)
COVID-19 , Deep Learning , Humans , Radiography, Thoracic/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Pandemics , COVID-19/diagnostic imaging , Retrospective Studies , Radiography , Machine Learning
2.
Sustainability ; 13(19):10918, 2021.
Article in English | MDPI | ID: covidwho-1444318

ABSTRACT

This article looks at studies on how to use business continuity management for Hong Kong’s virtual banks in order to reduce customer information risks, so as to maintain business sustainability. Firstly, the development of virtual banks in Hong Kong were investigated, the laws and regulations and regulatory policies of Hong Kong and the Mainland were benchmarked, and the main risks that may occur and be harmful to the bank business sustainability were analyzed. Considering the characteristics of virtual banks, the main concerns of public customers about the IT risks of virtual banks through questionnaire surveys were collected and analyzed. Moreover, the importance of business continuity management to virtual banks was drawn. Secondly, in the case studies, via understanding the overall situation of WeBank, its performance during the COVID-19 pandemic, and the regulations of the Monetary Authority of Singapore, the practice standards of virtual banks in business continuity management were further clarified. At the end, three suggestions for virtual banks in Hong Kong were put forward to reduce customer information security risks through business continuity management, thereby maintaining its business sustainability.

3.
Sci Rep ; 11(1): 15523, 2021 09 01.
Article in English | MEDLINE | ID: covidwho-1392879

ABSTRACT

Chest radiography (CXR) is the most widely-used thoracic clinical imaging modality and is crucial for guiding the management of cardiothoracic conditions. The detection of specific CXR findings has been the main focus of several artificial intelligence (AI) systems. However, the wide range of possible CXR abnormalities makes it impractical to detect every possible condition by building multiple separate systems, each of which detects one or more pre-specified conditions. In this work, we developed and evaluated an AI system to classify CXRs as normal or abnormal. For training and tuning the system, we used a de-identified dataset of 248,445 patients from a multi-city hospital network in India. To assess generalizability, we evaluated our system using 6 international datasets from India, China, and the United States. Of these datasets, 4 focused on diseases that the AI was not trained to detect: 2 datasets with tuberculosis and 2 datasets with coronavirus disease 2019. Our results suggest that the AI system trained using a large dataset containing a diverse array of CXR abnormalities generalizes to new patient populations and unseen diseases. In a simulated workflow where the AI system prioritized abnormal cases, the turnaround time for abnormal cases reduced by 7-28%. These results represent an important step towards evaluating whether AI can be safely used to flag cases in a general setting where previously unseen abnormalities exist. Lastly, to facilitate the continued development of AI models for CXR, we release our collected labels for the publicly available dataset.


Subject(s)
COVID-19/diagnostic imaging , Radiographic Image Interpretation, Computer-Assisted/methods , Tuberculosis/diagnostic imaging , Adult , Aged , Algorithms , Case-Control Studies , China , Deep Learning , Female , Humans , India , Male , Middle Aged , Radiography, Thoracic , United States
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