Abstract
The coronavirus disease 2019 (COVID-19) pandemic upended our approach to imaging community-acquired
pneumonia, and this will alter our diagnostic algorithms for years to come. In light
of these changes, it is worthwhile to consider several postpandemic scenarios of community-acquired
pneumonia: (1) patient with pneumonia and recent positive COVID-19 testing; (2) patient
with air space opacities and history of prior COVID-19 pneumonia (weeks earlier);
(3) multifocal pneumonia with negative or unknown COVID-19 status; and (4) lobar or
sublobar pneumonia with negative or unknown COVID-19 status. In the setting of positive
COVID-19 testing and typical radiologic findings, the diagnosis of COVID-19 pneumonia
is generally secure. The diagnosis prompts vigilance for thromboembolic disease acutely
and, in severely ill patients, for invasive fungal disease. Persistent or recurrent
air space opacities following COVID-19 infection may more often represent organizing
pneumonia than secondary infection. When COVID-19 status is unknown or negative, widespread
airway-centric disease suggests infection with mycoplasma, Haemophilus influenzae,
or several respiratory viruses. Necrotizing pneumonia favors infection with pneumococcus,
Staphylococcus, Klebsiella, and anaerobes. Lobar or sublobar pneumonia will continue to suggest the diagnosis
of pneumococcus or consideration of other pathogens in the setting of local outbreaks.
A positive COVID-19 test accompanied by these imaging patterns may suggest coinfection
with one of the above pathogens, or when the prevalence of COVID-19 is very low, a
false positive COVID-19 test. Clinicians may still proceed with testing for COVID-19
when radiologic patterns are atypical for COVID-19, dependent on the patient's exposure
history and the local epidemiology of the virus.
Keywords
community-acquired pneumonia - viral pneumonia - organizing pneumonia - COIVD-19 -
Staphylococcus
- computed tomography
