Diagnostic and Interventional Radiology
Chest Imaging - Original Article

Diagnostic performance of low-dose chest CT to detect COVID-19: A Turkish population study

1.

Department of Radiology, Giresun University, Faculty of Medicine, Giresun, Turkey

2.

Department of Radiology, Emergency Medicine, Giresun University, Faculty of Medicine, Giresun, Turkey

3.

Departments of Radiology and Infectious Disease and Clinical Microbiology, Giresun University, Faculty of Medicine, Giresun, Turkey

Diagn Interv Radiol 2021; 27: 181-187
DOI: 10.5152/dir.2020.20350
Read: 1494 Downloads: 245 Published: 02 September 2020

PURPOSE 
We aimed to evaluate the diagnostic performance of low-dose chest computed tomography (CT) in patients under investigation for coronavirus disease 2019 (COVID-19).

METHODS
This retrospective study included 330 patients suspected of having COVID-19 from March 15 to April 16, 2020. We examined 306 patients upon initial presentation using both CT and real-time reverse-transcriptase polymerase-chain-reaction (rRT-PCR). The diagnostic performance of CT was calculated using rRT-PCR as a reference. Clinical and laboratory data, CT characteristics, and lesion distribution were assessed for patients with a confirmed diagnosis via rRT-PCR. 

RESULTS
A total of 250 patients were finally diagnosed with COVID-19. Clinical and laboratory findings included myalgia or fatigue (76%), fever (64.8%), dry cough (60.8%), elevated levels of C-reactive protein (86.4%), procalcitonin (62%), and D-dimer (58.2%), increased neutrophil-lymphocyte ratio (NLR) (54.8%), and lymphopenia (34%). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the initial CT scan were 90.4% (95% IC, 86%–93%), 64.2% (95% IC, 50%–76%), 91.8% (95% IC, 88%–94%), and 60% (95% IC, 49%–69%), respectively. The percentage of patients diagnosed on the initial rRT-PCR test was 51.6% (n=129). Most frequent CT characteristics of COVID-19 in the subgroup of rRT-PCR-positive patients were multiple lesion (97.4%, n=220), followed by bilateral involvement (88.5%, n=200), peripheral distribution (74.3%, n=168), ground-glass opacity (GGO) (69.2%, n=157), subpleural curvilinear opacity (41.6%, n=104), and mixed GGOs (27.6%, n=67).

CONCLUSION
rRT-PCR may produce initial false negative results. For this reason, typical CT findings for COVID-19 should be known especially by radiologists. We suggest that patients with typical CT findings but negative rRT-PCR results should be isolated, and rRT-PCR should be repeated to avoid misdiagnosis.

You may cite this article as: Aslan S, Bekçi T, Çakır IM, Ekiz M, Yavuz I, Şahin AM. Diagnostic performance of low-dose chest CT to detect COVID-19: A Turkish population study. Diagn Interv Radiol 2021; 27: 181–187

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