The low-to-moderate specificity of the chest CT scan can be partly explained by initial false-negative reverse transcription polymerase chain reaction (RT-PCR) tests in COVID-19 patients, according to Belgian radiologists who have shared their experiences of the first wave of the pandemic.
Dr. Vikram rao Bollineni, PhD, and colleagues from University Hospital Brussels (UZ Brussel) and Free University of Brussels (VUB) analyzed the electronic records of 240 patients (145 male and 95 female; mean age 63, range 15-104) who presented themselves at the emergency department between 29 March 2020 and 15 April 2020. All patients had symptoms of dyspnea, cough, and fever and underwent both chest CT imaging and laboratory RT-PCR assay (pharyngeal swab within an interval of four days).
"Our experience during the epidemic outbreak and the post-epidemic phase confirms that the chest CT scan is mainly useful during an epidemic outbreak and in symptomatic patients," the authors wrote in an article posted by Insights into Imaging on 29 January. "We can conclude that the value of the chest CT scan as a screening tool lies principally in its negative predictive value."
