Radiology departments have been working hard all over the world in these last few months because CT scans, which may show distinctive changes in patients’ lungs, are one of the main ways of diagnosing COVID-19. But “after each potentially infected patient is scanned, the machine must be completely disinfected. Therefore, CT isn’t recommended to screen for COVID-19,” write Saurabh Jha, MBBS, MRCS and Scott Simpson, DO, in an editorial for MedScape.
Of course, CT will still be used in patients with acute respiratory symptoms, some of whom may have coronavirus infection. How should radiologists report findings suggestive of COVID-19 in patients imaged for other conditions? The answer isn’t straightforward and needs careful thought.
When present, the findings of COVID-19 on CT — notably peripheral ground-glass opacities — are sensitive but not specific for coronavirus; other pneumonias resemble COVID-19, particularly viral and Pneumocystis jirovecii pneumonia, cryptogenic organizing pneumonia, and acute lung injury from drug toxicity, hypersensitivity, and autoimmune diseases, to name a few pathologies. This means that false-positive errors don’t occur so much from falsely labeling healthy people with COVID-19 infection but rather from falsely attributing COVID-19 in ill patients with other acute respiratory pathologies — ie, misattribution.
Radiologists thus face a familiar dilemma, choosing between overcalling or undercalling, and both errors are costly. If radiologists omit COVID-19 infection in their reports when they see suggestive findings, and patients are actually infected, they won’t be appropriately isolated and could infect others. If radiologists call COVID-19 infection when they see suggestive findings, and patients aren’t infected, wrong protocols will be activated and they may not be treated for the condition they actually have, not to mention that the CT scanner will be unnecessarily nonoperational until decontaminated.
Read more from MedScape.