Covid-19 II

Description

Severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2, or COrona VIrus Disease 19 (Covid-19) has changed the world entirely in just a few months. The declaration of a worldwide pandemic (World Health Organisation (WHO), March 11th, 2020) followed the initial report of a new Coronavirus type pneumonia in Wuhan at the end of December 2019 at an astonishing speed. Since then, extensive measures have been taken by local governments including varying degrees of "lock-down" among societies. Hospitals worldwide have also gone to extreme lengths to be able to deal with the huge numbers of ill patients continuously arriving at their doors.

Covid-19 infection is most frequently associated with mild symptoms (80%), however in 15% of cases, patients are severely ill and in 5% patients are critically ill, requiring non-invasive or mechanical ventilation. Symptoms of Covid-19 infections include a fever and dry cough in most cases, and a diversity of other symptoms are reported as well (including chest distress, gastrointestinal symptoms and CNS symptoms - including headaches or even encephalitis/meningitis).

The gold-standard for the diagnosis of Covid-19 infection is polymerase chain reaction (PCR). However, since the sensitivity for this PCR technique is approximately 60-70%, false test results may be obtained initially, and retesting is sometimes needed. This causes delays in the availability of a PCR test result, specially when combined with low availability of the test in some parts of the world. As a result, imaging (CT or CXR) has been proposed as a tool to help triage and provide early diagnose of Covid-19 pneumonia. However, there are problems associated with this, mainly related to the significant overlap between Covid-19 pneumonia findings and other viral pneumonias (including e.g. influenza, H1N1, Sars, Mers, etc.) but also given the fact that CT chest may be normal in the initial stages of the disease.

Therefore, CT is not currently recommended as a screening tool by the Center of Disease Control (CDC), the BSTI and others. However, CT findings may be of importance to add to the pre-test probability assessment, helping to distinguish between severe and non-severe cases, assess deterioration or discordant clinical course, assess complications and to look for an alternative diagnosis (BSTI). As recently published by the Fleischner Society, imaging may also be used for the medical triage of patients with suspected Covid-19, alongside moderate-severe clinical features and a high pre-test probability of disease, in a resource-constrained environment.

This Reporting Simulator module and pre-recorded webinar (as available on this website) aims to help radiologists get used to the imaging findings that are frequently, and some less frequently, encountered in Covid-19 pneumonia. A step-by-step assessment is used to get to a classification of the degree of certainty for the presence or absence of Covid-19 pneumonia, based on the British Society of Thoracic Imaging (BSTI).

And, finally, we are now living in a world that seems to be changing from day-to-day. New publications and new studies are emerging every day in a collective attempt to understand this threatening new corona virus. Knowledge is increasing rapidly, and participants are highly encouraged to continue monitoring their Societies websites for new updates and changes. An overview of interesting sites is mentioned in the section ‘learning material’ and may be subject to daily changes.

Learning objectives

• To review the BSTI classification system for differentiation of classic, probable and indeterminate Covid-19 pneumonia and to differentiate them from non-Covid-19 pneumonia.
• To get accustomed to the imaging findings as frequently seen in classic and probable Covid-19 pneumonia.
• To implement a standardised approach to the assessment of CT studies obtained in suspected or incidental Covid-19 pneumonia.

Level

Level II - General radiologist

Additional info

Technical requirements

The training platform runs entirely in the browser but the online PACS places a considerable load on the hardware and internet connection when viewing and loading cases.