Chest CT-based differential diagnosis of 28 patients with suspected corona virus disease 2019 (COVID-19)

Abstract

Objectives: The chest CT findings that can distinguish patients with corona virus disease 2019 (COVID-19) from those with clinically suspected COVID-19 but subsequently found to be COVID-19 negative have not previously been described in detail. The purpose of this study was to determine the distinctions among patients with COVID-19 by comparing the imaging findings of patients with suspected confirmed COVID-19 and those of patients initially suspected to have COVID-19 who were ultimately negative for the disease.

Methods: 28 isolated suspected in-patients with COVID-19 were enrolled in this retrospective study from January 22, 2020 to February 6, 2020. 12 patients were confirmed to have positive severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) RNA results, and 16 patients had negative results. The thin-section CT imaging findings and clinical and laboratory data of all the patients were evaluated.

Results: There were no significant differences between the 12 confirmed COVID-19 (SARS-Cov-2-positive) patients and 16 SARS-CoV-2-negative patients in epidemiology and most of the clinical features or laboratory data. The CT images showed that the incidence of pure/mixed ground-glass opacities (GGOs) was not different between COVID-19 and SARS-CoV-2-negative patients [9/12 (75.0%) vs 10/16 (62.5%), p = 0.687], but pure/mixed GGOs in the peripheral were more common in patients with COVID-19 [11/12 (91.7%) vs 6/16 (37.5%), p = 0.006]. There were no significant differences in the number of lesions, bilateral lung involvement, large irregular/patchy opacities, rounded opacities, linear opacities, crazy-paving patterns, halo signs, interlobular septal thickening or air bronchograms.

Conclusions: Although peripheral pure/mixed GGOs on CT may help distinguish patients with COVID-19 from clinically suspected but negative patients, CT cannot replace RT-PCR testing.

Advances in knowledge: Peripheral pure/mixed GGOs on-chest CT findings can be helpful in distinguishing patients with COVID-19 from those with clinically suspected COVID-19 but subsequently found to be COVID-19 negative.

Figure 1.

Flowchart of the study population. Note: #1 The interval between two times was more than 24 h; #2 The last follow-up was on February 20, 2020; CT = computed tomography; COVID-19 = corona virus disease 2019; SARS-CoV-2=severe acute respiratory syndrome corona virus 2.

Figure 2.

(a-b) An axial CT image obtained without intravenous contrast in a 43-year-old male showed peripheral/subpleural patchy consolidation in the anterior of the left upper lobe, with interlobular septal thickening, air bronchogram and linear opacities. He had a history of living in Xiaogan, Hubei Province and presented with fever for 1 week. Nasopharyngeal swabs for SARS-CoV-2 RNA were positive.

Figure 3.

(a-b) A31-year-old male with a history of travelling on a cruise presented with fever, diarrhoea, sore throat and fatigue. (a) Axial thin-section non-contrast CT image on February 1, 2020, showed peripheral/subpleural, patchy, rounded, mixed GGOs in the right lower lobe, with interlobular septal thickening and crazy-paving patterns. (b) Follow-up CT image on February 9, 2020, showed that the lesions were obviously resolved after anti-infection therapy. Nasopharyngeal swabs for SARS-CoV-2 RNA were negative.

Figure 4.

(a-b) A 56-year-old female with a history of travelling to Guangzhou from Wuhan presented with fever, cough and diarrhoea for 2 days. (a) (b) Axial thin-section non-contrast CT image showed bilateral peripheral/subpleural, patchy, pure/mixed GGOs with interlobular septal thickening and crazy-paving patterns. Two consecutive nasopharyngeal swabs for SARS-CoV-2 RNA(the interval between the two swabs more than 24 h) were negative.