Clinical usefulness of tomographic standards for COVID-19 pneumonia diagnosis: Experience from a Brazilian reference center

Abstract

Background COVID-19 is a new disease and the most common complication is pneumonia. The Radiological Society of North America (RSNA) proposed an expert consensus for imaging classification for COVID-19 pneumonia. Objective To evaluate sensitivity, specificity, accuracy, and reproducibility of chest CT standards in the beginning of the Brazilian COVID-19 outbreak. Methods Cross-sectional study performed from March 1st to April 14th, 2020. Patients with suspected COVID-19 pneumonia submitted to RT-PCR test and chest computed tomography (CT) were included. Two thoracic radiologists blinded for RT-PCR and clinical and laboratory results classified every patient scan according to the RSNA expert consensus. A third thoracic radiologist also evaluated in case of discordance, and consensus was reached among the three radiologists. A typical appearance was considered a positive chest CT for COVID-19 pneumonia. Sensitivity, specificity, positive and negative predictive values were calculated. Cohen’s kappa coefficient was used to evaluate intra- and inter-rater agreements. Results A total of 159 patients were included (mean age 57.9 ± 18.0 years; 88 [55.3%] males): 86 (54.1%) COVID-19 and 73 (45.9%) non-COVID-19 patients. Eighty (50.3%) patients had a positive CT for COVID-19 pneumonia. Sensitivity and specificity of typical appearance were 88.3% (95%CI, 79.9–93.5) and 94.5% (95%CI, 86.7–97.8), respectively. Intra- and inter-rater agreement were assessed (Cohen’s kappa = 0.924, P = 0.06; Cohen’s kappa=0.772, P = 0.05, respectively). Conclusion Chest CT categorical classification of COVID-19 findings is reproducible and demonstrates high level of agreement with clinical and RT-PCR diagnosis of COVID-19. In RT-PCR scarcity scenarios or in equivocal cases, it may be useful for attending physicians in the evaluation of suspected COVID-19 pneumonia patients attended at the emergency unit.

Validation of the North America expert consensus statement on reporting CT findings for COVID-19 in individuals with lung cancer

“…Since prior disease is expected to interfere with diagnostic accuracy, the results of our study add substantial novel information by demonstrating adequate performance of chest CT in this population. It is interesting to note that the kappa reported in our study was lower than the agreement previously reported ( 25 , 26 ). However, our findings are in line with another study that reported a lower agreement ( 27 ).…”

The role of chest imaging in the diagnosis, management, and monitoring of coronavirus disease 2019 (COVID-19)

“…They also revealed that PPV of “typical appearance” was 40.0% at a prevalence of 16.7% and increased to 87.8% at 46.4% [ 61 ]. Similar trends were observed in reports from other countries, i.e., Brazil [ 60 , 63 , 66 , 67 ], Japan [ 49 ], and USA [ 64 ] and other institutions in Italy [ 61 , 62 , 65 ]. Regarding the diagnostic performance against other viral pneumonias, a retrospective cohort study from Brazil reported similar results with a sensitivity and specificity of 73.6% and 97.7%, respectively, for “typical appearance” [ 65 ].…”

Medical imaging technologies applied to the COVID-19 context

“…It is noteworthy that such features are not uniquely related to COVID-19 pneumonia and may be similar to other processes such as influenza pneumonia and organizing pneumonia. Moreover, with the evolution of the disease, patients with COVID-19 may have coexisting infections, such as secondary bacterial pneumonia, which may mimic atypical findings of COVID-19, such as lobar consolidation [15,16].…”