EuSEM COVID Imaging Modalities Webinar Summary

CXR 

• Is needed to exclude other diagnoses 

• Not a good rule out test for for asymptomatic patient

• Normal CXR in early or mild cases won’t exclude the disease 

• CXR not specific for single conditions (in case of COVID PCR is specific)

• Remember sensitivity and specificity changes with prevalence of the disease (consider the pandemic)

• Pooled sensitivity of CXR and PCR not done yet

• 3 retrospective studies (CXR not sensitive). Sensitivity changes over time

• In COVID it can still guide severity/monitoring/complications 

• Findings are changed over time (depends when pt presents to ED )

• Consolidation/ground glass changes. Bi-basal infiltrates predominates

• Lobar pneumonia/Cavitation/pleural effusions NOT COMMON

• But COVID might be a co-presentation and with other co-morbidities such as decompensation CCF/COPD exacerbation.

Lung US

• The best place is just after triaging for all patients 

• Standardise the scanning (12 areas) and probe type (linear for superficial, curvilinear for deeper penetration)

• Pneumonia- irregular pleural lines vs Pulmonary Oedema-pleural lines are normal and has hydrostatic diffusion

  Infection- white spots, which is air trapped within lung tissue, static or dynamic bronchograms. Present and static, then most likely atelectasis

• In COVID B-lines scattered and separated first, but then become confluent 

Lung CT

Non-specific CT Changes

Specific CT Findings

• Not a gold standard, but give the most conclusive results amongst all the imaging.

• The findings are not specific

• For CT scan pre-test needs to be carefully thought about, and patient selected for it 

• Not scan pt that are asymotamatic, or mild features 

• one third COVID, one third infection other causes, one third pulmonary embolism and other causes 

• CTPA- very complicated to get the scan done in the first place, what do you do with the results most likely thrombosis not originating from the lower limbs but produced insitu. D-dimer are not the specific 

  PE unrelated (usual pre-test probability) vs related with COVID (pt getting worse, and peripheral circulation not seen on CTPA any way)

  CTPA if more hypoxic than the imaging suggest, or high suspecion