Why is chest CT important for early diagnosis of COVID-19?

COVID-19 diagnosis is based on the identification of viral RNA through Reverse Transcription Polymerase Chain Reaction (RT-PCR) from oral-nasopharyngeal swabs, which however presents suboptimal sensitivity and may require several hours in overstressed laboratories.

These drawbacks have called for an additional, complementary first line approach.

Computed Tomography (CT) Scan is the gold standard method for the detection of interstitial pneumonia, a hallmark feature of COVID-19, often present in the asymptomatic stage of the disease.

In a new study, authors show that CT Scan presents a sensitivity of 95.48%, vastly outperforming RT-PCR (Reverse Transcription Polymerase Chain Reaction).

Additionally, as diagnostic accuracy is influenced by disease prevalence, authors argue that predictive values provide a more precise measure of CT Scan reliability in the current pandemics. They have generated a model showing that CT scan is endowed with a high Negative Predictive Value (NPV) ―greter than 90%―, and Positive Predictive Value (PPV) ―between 69 and 84%―, for the range of prevalence seen in countries with rampant dissemination.

Finally, authors conclude that CT Scan is an expedite and reliable diagnostic tool to support first line triage of suspect COVID-19 patients in areas where the diffusion of the virus is widespread.

Link to the paper: https://doi.org/10.1101/2020.03.30.20047985

Editorial Disclaimer: information published during the 2020 COVID-19 pandemic may be updated frequently to reflect the dynamic nature of current understanding.

Related Posts

Social Media