ROLE OF HIGH-RESOLUTION COMPUTED TOMOGRAPHY (HRCT) IN THE DIAGNOSIS OF REVERSE TRANSCRIPTASE POLYMERASE CHAIN REACTION (RT-PCR) NEGATIVE COVID-19 INFECTION CASES
Objective: During the early phases of COVID-19 infection the diagnosis of the disease is made difficult by the negative result of RT-PCR test. RT-PCR shows variable sensitivity to detect COVID-19 infection and has a lengthy turn around time. These two limitations of RT-PCR test results in delayed detection of COVID-19 infection, delayed isolation of these suspected cases and undermines efforts at the containment of infection. In this study we investigated the role of High Resolution Computed Tomography(HRCT) in the diagnosis of COVID-19 infections in patients who tested negative for COVID-19 infections on RT-PCR. We studied 41 patients suspected of COVID-19 who presented with fever, dry cough, tiredness, sore throat, headache, breathlessness and diarrhea.30 patients were male and 11 were female. Initial RT-PCR for COVID-19 was negative. HRCT was done which showed pulmonary involvement in 25 out of 41 patients. Findings on HRCT were ground glass haze, multilobular involvement, consolidation and vascular enlargement. This study has shown that HRCT has a role in early detection of RT-PCR negative COVID-19 infection cases.
Material and Methods: This study was carried out between April 2020 and June 2020 in the department of Radiology Fauji Foundation hospital Rawalpindi. We studied 41 suspected patients of COVID-19 infection, 30 were male and 11 were female. Male to Female ratio was 3:1. Age range was 30-65 years. All these patients were suspected of COVID-19 infection. They presented with fever, dry cough, tiredness, sore throat, headache, breathlessness and diarrhea. RT- PCR test was performed at National Institute of Health (NIH) Islamabad for COVID-19 infection which was initially negative in all these cases. All these cases underwent HRCT examination.
Address for correspondence
Dr.Muhammad Harris Ayub Email: [email protected]
Department of Radiology Fauji Foundation Hospital Rawalpindi Pakistan
Results: Out of 41 patients, 35 patients showed pulmonary involvement. Findings on HRCT were bilateral involvement of lungs (80% cases), peripheral distribution (74.8% case), posterior involvement (80% cases),
Multi lobular involvement (89.3% cases), ground glass haze (86.6% cases), consolidation (33% cases) and vascular enlargement (60% cases). RT-PCR was repeated after one week interval which was positive in 21 patients and negative in 20 patients.
Conclusion: In this study 41 suspected patients of COVID-19 were enrolled who presented with signs and symptoms of COVID-19 infections; however RT-PCR testing was negative in all cases. Initially on HRCT scan pulmonary involvement was seen in 35 out of 41 patients. Findings of HRCT were ground glass haze, multilobular involvement, consolidation and vascular enlargement. This study has shown that HRCT has a role in early detection of COVID-19 infection cases in which RT-PCR is negative.