COVID-Net L2C-ULTRA: An Explainable Linear-Convex Ultrasound Augmentation Learning Framework to Improve COVID-19 Assessment and Monitoring

While no longer a public health emergency of international concern, COVID-19 remains an established and ongoing global health threat. As the global population continues to face significant negative impacts of the pandemic, there has been an increased usage of point-of-care ultrasound (POCUS) imaging...

Full description

Bibliographic Details
Main Authors: E. Zhixuan Zeng, Ashkan Ebadi, Adrian Florea, Alexander Wong
Format: Article
Language:English
Published: MDPI AG 2024-03-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/24/5/1664
_version_ 1797263838963302400
author E. Zhixuan Zeng
Ashkan Ebadi
Adrian Florea
Alexander Wong
author_facet E. Zhixuan Zeng
Ashkan Ebadi
Adrian Florea
Alexander Wong
author_sort E. Zhixuan Zeng
collection DOAJ
description While no longer a public health emergency of international concern, COVID-19 remains an established and ongoing global health threat. As the global population continues to face significant negative impacts of the pandemic, there has been an increased usage of point-of-care ultrasound (POCUS) imaging as a low-cost, portable, and effective modality of choice in the COVID-19 clinical workflow. A major barrier to the widespread adoption of POCUS in the COVID-19 clinical workflow is the scarcity of expert clinicians who can interpret POCUS examinations, leading to considerable interest in artificial intelligence-driven clinical decision support systems to tackle this challenge. A major challenge to building deep neural networks for COVID-19 screening using POCUS is the heterogeneity in the types of probes used to capture ultrasound images (e.g., convex vs. linear probes), which can lead to very different visual appearances. In this study, we propose an analytic framework for COVID-19 assessment able to consume ultrasound images captured by linear and convex probes. We analyze the impact of leveraging extended linear-convex ultrasound augmentation learning on producing enhanced deep neural networks for COVID-19 assessment, where we conduct data augmentation on convex probe data alongside linear probe data that have been transformed to better resemble convex probe data. The proposed explainable framework, called COVID-Net L2C-ULTRA, employs an efficient deep columnar anti-aliased convolutional neural network designed via a machine-driven design exploration strategy. Our experimental results confirm that the proposed extended linear–convex ultrasound augmentation learning significantly increases performance, with a gain of 3.9% in test accuracy and 3.2% in AUC, 10.9% in recall, and 4.4% in precision. The proposed method also demonstrates a much more effective utilization of linear probe images through a 5.1% performance improvement in recall when such images are added to the training dataset, while all other methods show a decrease in recall when trained on the combined linear–convex dataset. We further verify the validity of the model by assessing what the network considers to be the critical regions of an image with our contribution clinician.
first_indexed 2024-04-25T00:19:23Z
format Article
id doaj.art-c60ceeb6eb464ba7b60a1b0a90425917
institution Directory Open Access Journal
issn 1424-8220
language English
last_indexed 2024-04-25T00:19:23Z
publishDate 2024-03-01
publisher MDPI AG
record_format Article
series Sensors
spelling doaj.art-c60ceeb6eb464ba7b60a1b0a904259172024-03-12T16:55:34ZengMDPI AGSensors1424-82202024-03-01245166410.3390/s24051664COVID-Net L2C-ULTRA: An Explainable Linear-Convex Ultrasound Augmentation Learning Framework to Improve COVID-19 Assessment and MonitoringE. Zhixuan Zeng0Ashkan Ebadi1Adrian Florea2Alexander Wong3Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, CanadaDepartment of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, CanadaDepartment of Emergency Medicine, McGill University, Montreal, QC H4A 3J1, CanadaDepartment of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, CanadaWhile no longer a public health emergency of international concern, COVID-19 remains an established and ongoing global health threat. As the global population continues to face significant negative impacts of the pandemic, there has been an increased usage of point-of-care ultrasound (POCUS) imaging as a low-cost, portable, and effective modality of choice in the COVID-19 clinical workflow. A major barrier to the widespread adoption of POCUS in the COVID-19 clinical workflow is the scarcity of expert clinicians who can interpret POCUS examinations, leading to considerable interest in artificial intelligence-driven clinical decision support systems to tackle this challenge. A major challenge to building deep neural networks for COVID-19 screening using POCUS is the heterogeneity in the types of probes used to capture ultrasound images (e.g., convex vs. linear probes), which can lead to very different visual appearances. In this study, we propose an analytic framework for COVID-19 assessment able to consume ultrasound images captured by linear and convex probes. We analyze the impact of leveraging extended linear-convex ultrasound augmentation learning on producing enhanced deep neural networks for COVID-19 assessment, where we conduct data augmentation on convex probe data alongside linear probe data that have been transformed to better resemble convex probe data. The proposed explainable framework, called COVID-Net L2C-ULTRA, employs an efficient deep columnar anti-aliased convolutional neural network designed via a machine-driven design exploration strategy. Our experimental results confirm that the proposed extended linear–convex ultrasound augmentation learning significantly increases performance, with a gain of 3.9% in test accuracy and 3.2% in AUC, 10.9% in recall, and 4.4% in precision. The proposed method also demonstrates a much more effective utilization of linear probe images through a 5.1% performance improvement in recall when such images are added to the training dataset, while all other methods show a decrease in recall when trained on the combined linear–convex dataset. We further verify the validity of the model by assessing what the network considers to be the critical regions of an image with our contribution clinician.https://www.mdpi.com/1424-8220/24/5/1664lung ultrasonic imaginglinear–convex augmentationCOVID-19 assessmentdeep explainable architecture
spellingShingle E. Zhixuan Zeng
Ashkan Ebadi
Adrian Florea
Alexander Wong
COVID-Net L2C-ULTRA: An Explainable Linear-Convex Ultrasound Augmentation Learning Framework to Improve COVID-19 Assessment and Monitoring
Sensors
lung ultrasonic imaging
linear–convex augmentation
COVID-19 assessment
deep explainable architecture
title COVID-Net L2C-ULTRA: An Explainable Linear-Convex Ultrasound Augmentation Learning Framework to Improve COVID-19 Assessment and Monitoring
title_full COVID-Net L2C-ULTRA: An Explainable Linear-Convex Ultrasound Augmentation Learning Framework to Improve COVID-19 Assessment and Monitoring
title_fullStr COVID-Net L2C-ULTRA: An Explainable Linear-Convex Ultrasound Augmentation Learning Framework to Improve COVID-19 Assessment and Monitoring
title_full_unstemmed COVID-Net L2C-ULTRA: An Explainable Linear-Convex Ultrasound Augmentation Learning Framework to Improve COVID-19 Assessment and Monitoring
title_short COVID-Net L2C-ULTRA: An Explainable Linear-Convex Ultrasound Augmentation Learning Framework to Improve COVID-19 Assessment and Monitoring
title_sort covid net l2c ultra an explainable linear convex ultrasound augmentation learning framework to improve covid 19 assessment and monitoring
topic lung ultrasonic imaging
linear–convex augmentation
COVID-19 assessment
deep explainable architecture
url https://www.mdpi.com/1424-8220/24/5/1664
work_keys_str_mv AT ezhixuanzeng covidnetl2cultraanexplainablelinearconvexultrasoundaugmentationlearningframeworktoimprovecovid19assessmentandmonitoring
AT ashkanebadi covidnetl2cultraanexplainablelinearconvexultrasoundaugmentationlearningframeworktoimprovecovid19assessmentandmonitoring
AT adrianflorea covidnetl2cultraanexplainablelinearconvexultrasoundaugmentationlearningframeworktoimprovecovid19assessmentandmonitoring
AT alexanderwong covidnetl2cultraanexplainablelinearconvexultrasoundaugmentationlearningframeworktoimprovecovid19assessmentandmonitoring