Chest CT More Sensitive Than RT-PCR for Diagnosing COVID-19

For those with negative RT-PCR results but positive chest CT scan, 48 percent thought to be highly likely cases


TUESDAY, March 3, 2020 (HealthDay News) -- Chest computed tomography (CT) has higher sensitivity for detecting 2019 novel coronavirus disease (COVID-19) than reverse-transcription polymerase chain reaction (RT-PCR) tests, according to a study published online Feb. 26 in Radiology.

Tao Ai, M.D., Ph.D., from Huazhong University of Science and Technology in Wuhan, China, and colleagues examined the diagnostic value and consistency of chest CT versus an RT-PCR assay of throat swab samples in 1,014 patients with COVID-19 who underwent both chest CT and RT-PCR tests.

The researchers found that 59 and 88 percent of the patients had positive RT-PCR results and chest CT scans, respectively. Based on positive RT-PCR results, the sensitivity of chest CT in suggesting COVID-19 was 97 percent. Seventy-five percent of the patients with negative RT-PCR results had positive chest CT findings; of these, 48 percent were considered highly likely cases and 33 percent were considered probable cases. The mean interval time between the initial negative to positive RT-PCR results was 5.1 ± 1.5 days; while the initial positive to subsequent negative RT-PCR result was 6.9 ± 2.3 days. An initial positive CT consistent with COVID-19 prior (or in parallel) to the initial positive RT-PCR result was seen in 60 to 93 percent of cases. There was improvement in follow-up chest CT scans before RT-PCR results turned negative in 42 percent of cases.

"Chest CT should be considered for the COVID-19 screening, comprehensive evaluation, and following-up, especially in epidemic areas with high pretest probability for disease," the authors write.

One author is an employee of Julei Technology Company.

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