Unveiling COVID-19 from Chest X-ray with deep learning: a hurdles race with small data

The possibility to use widespread and simple chest X-ray (CXR) imaging for early screening of COVID-19 patients is attracting much interest from both the clinical and the AI community. In this study we provide insights and also raise warnings on what is reasonable to expect by applying deep-learning to COVID classification of CXR images. We provide a methodological guide and critical reading of an extensive set of statistical results that can be obtained using currently available datasets. In particular, we take the challenge posed by current small size COVID data and show how significant can be the bias introduced by transfer-learning using larger public non-COVID CXR datasets. We also contribute by providing results on a medium size COVID CXR dataset, just collected by one of the major emergency hospitals in Northern Italy during the peak of the COVID pandemic. These novel data allow us to contribute to validate the generalization capacity of preliminary results circulating in the scientific community. Our conclusions shed some light into the possibility to effectively discriminate COVID using CXR

Convolutional Neural Network-Based Automatic Analysis of Chest Radiographs for the Detection of COVID-19 Pneumonia: A Prioritizing Tool in the Emergency Department, Phase I Study and Preliminary “Real Life” Results

The aim of our study is the development of an automatic tool for the prioritization of COVID-19 diagnostic workflow in the emergency department by analyzing chest X-rays (CXRs). The Convolutional Neural Network (CNN)-based method we propose has been tested retrospectively on a single-center set of 542 CXRs evaluated by experienced radiologists. The SARS-CoV-2 positive dataset (n = 234) consists of CXRs collected between March and April 2020, with the COVID-19 infection being confirmed by an RT-PCR test within 24 h. The SARS-CoV-2 negative dataset (n = 308) includes CXRs from 2019, therefore prior to the pandemic. For each image, the CNN computes COVID-19 risk indicators, identifying COVID-19 cases and prioritizing the urgent ones. After installing the software into the hospital RIS, a preliminary comparison between local daily COVID-19 cases and predicted risk indicators for 2918 CXRs in the same period was performed. Significant improvements were obtained for both prioritization and identification using the proposed method. Mean Average Precision (MAP) increased (p < 1.21 × 10(−21) from 43.79% with random sorting to 71.75% with our method. CNN sensitivity was 78.23%, higher than radiologists’ 61.1%; specificity was 64.20%. In the real-life setting, this method had a correlation of 0.873. The proposed CNN-based system effectively prioritizes CXRs according to COVID-19 risk in an experimental setting; preliminary real-life results revealed high concordance with local pandemic incidence

Percutaneous closure of accidentally subclavian artery catheterization: time to change first line approach?

PURPOSE: To present our experience and provide a literature review dissertation about the use of a suture-mediated percutaneous closure device (Perclose Proglide -PP- Abbott Vascular Inc., Santa Clara, CA, USA) to achieve hemostasis for unintended subclavian arterial catheterization during central venous line placement. MATERIALS & METHODS: Since October 2020, we have successfully treated four consecutive patients with a central venous catheter (8 to 12 French) in the subclavian artery. In each patient, we released a PP, monitoring its efficacy by performing a subclavian angiogram and placing, as a rescue strategy, an 8 mm balloon catheter near the entry point of the misplaced catheter. Primary outcome is technical and clinical success. Technical success is defined as absence of bleeding signs at completion angiography, while clinical success is a composite endpoint defined as absence of hematoma, hemoglobin loss at 12 and 24 h, and absence of procedure-related reintervention (due to vessel stenosis, pseudoaneurysm or distal embolization). RESULTS: Technical success was obtained in 75% of cases. In one patient a mild extravasation was resolved after 3 min of balloon catheter inflation. No early complications were observed for all patients. CONCLUSIONS: PP showed a safe and effective therapeutic option in case of unintentional arterial cannulation. It can be considered as first-line strategy, as it does not preclude the possibility to use other endovascular approaches in case of vascular closure device failure

PrepNet : a convolutional auto-encoder to homogenize CT scans for cross-dataset medical image analysis

With the spread of COVID-19 over the world, the need arose for fast and precise automatic triage mechanisms to decelerate the spread of the disease by reducing human efforts e.g. for image-based diagnosis. Although the literature has shown promising efforts in this direction, reported results do not consider the variability of CT scans acquired under varying circumstances, thus rendering resulting models unfit for use on data acquired using e.g. different scanner technologies. While COVID-19 diagnosis can now be done efficiently using PCR tests, this use case exemplifies the need for a methodology to overcome data variability issues in order to make medical image analysis models more widely applicable. In this paper, we explicitly address the variability issue using the example of COVID-19 diagnosis and propose a novel generative approach that aims at erasing the differences induced by e.g. the imaging technology while simultaneously introducing minimal changes to the CT scans through leveraging the idea of deep autoencoders. The proposed prepossessing architecture (PrepNet) (i) is jointly trained on multiple CT scan datasets and (ii) is capable of extracting improved discriminative features for improved diagnosis. Experimental results on three public datasets (SARS-COVID-2, UCSD COVID-CT, MosMed) show that our model improves cross-dataset generalization by up to 11:84 percentage points despite a minor drop in within dataset performance