Role of High Resolution Computed Tomography (HRCT) In Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) Test Negative Symptomatic Patients for Covid-19 Pneumonia

Abstract

Background: For the diagnosis of SARS-CoV-2 infection RT-PCR test has become a standard. Because of insufficient specimen or laboratory error RT-PCR testing results may be falsely negative. HRCT has a higher rate of detection of patients with disease in incubation period, particularly with initial negative RT-PCR results. Thus, CT is helpful for early diagnosis, timely isolation, and treatment of COVID-19 pneumonia. Aim: The aim of the study is to know the role of High-resolution computed tomography (HRCT) in those with negative initial RT-PCR results with highly suspected SARS CoV-2 infection. Materials and Methods: For a duration of 6 months from May 2020 to October 2020 , A cross sectional study was conducted with a total of 100 patients after obtaining the informed consent at Department of Radio diagnosis , KR Hospital attached to Mysore Medical College and Research Institute, Mysore. High resolution Computed tomography (HRCT) of thorax was performed with 128 slice single source dual energy Multi-detector Computed tomography machine. Results: In our study Ground glass opacity and consolidation are two main HRCT features of COVID-19 lesions in RTPCR negative symptomatic patients and is seen among 70 and 32 patients respectively, while combination of ground glassing and consolidation was seen in 42 patients. The lesions were predominantly peripheral or subpleural in 44 patients (48%), both subpleural and centroparenchymal in 45 patients (50%) and only 1 patient (1.1%) in centroparenchymal location. Conclusion: HRCT chest scan plays an important role in detecting COVID-19 in those symptomatic patients in whom RT-PCT test results are negative. In the context of the current pandemic and multiple genetic mutations of the virus, in patients with clinical symptoms or a history of exposure, positive HRCT should be regarded as strongly suspicious for COVID-19 pneumonia, despite negative RT-PCR test results. Keywords: Ground glass opacity, Consolidation, Crazy paving.