 Good morning members of the faculty and respected delegates. I am Dr. Redhukha Endurkar, a third-year resident from D.Y. Partial Hospital, Navi, Mumbai. Title of my paper is High-Resolution Computer Tomography and RT-PCR Correlation for Diagnosis of COVID-19. To restrain the spread of pandemic of COVID-19, we need an accurate and quick diagnostic tool. The diagnostic tool should be cost-effective and sensitive. Real-time RT-PCR has been widely accepted throughout the world and is being done as a primary screening test, while HRCRT is done to analyze lung involvement and extent of the disease. It has been found that a significant number of patients with negative RT-PCR test have features of HRCRT suggestive of COVID-19. This study entails comparison of HRCRT and RT-PCR in terms of efficacy, cost and rapidness for diagnosis of COVID-19 infection. As we all know, COVID-19 is a viral disease caused by SARS-CoV-2 virus. Real-time RT-PCR is a WHO-approved tool for the diagnosis of COVID-19 and is the basis for further management. RT-PCR is very specific for detection of COVID-19. However, the sensitivity is 65-70%. It is reported that many suspected cases with typical clinical characteristics of COVID-19 and identical specific CT images were not diagnosed on RT-PCR. Thus, a negative result does not exclude the possibility of COVID-19 infection and should not be used as the only criteria for treatment or patient management decisions. On computer tomography, following features are found in patients with COVID-19, ground-glass opacities, which is the most common feature, crazy paving pattern, vascular dilatation, traction bronchitis, fibrosis and consolidation. Based on the features found on CT, staging of the disease can be done i.e. early, progressive, peak or resolution. Involvement of the lung parankama helps in determining the severity score for prognosis and progression of the disease, which can be either 5-25%, 26-49%, 50-75% or more than 75% of the involvement. The total CT score is the sum of individual low-bar scores and can range from 0, which is no involvement, to 25, which is maximum involvement, when all the five lobes show more than 75% involvement. Other findings could include septal thickening, bronchitis, pleural thickening, sub-pleural involvement in the later stages of the disease. We compared HRCT and RTPCR studies of the suspected patients in D.Y. Patel Hospital, Navi, Mumbai, between April 2020 to April 2021. It is a retrospective study done on GE Optima 660-128 slice machine. The sample size is 932 patients. Inclusion criteria is patients with flu-like symptoms and patients willing to do both HRCT and RTPCR study. Exclusion criteria is patients with both HRCT and RTPCR status negative. Aims and objectives are to evaluate patients of false negative RTPCR results to detect COVID-19 and to minimize the percentage of false negative studies, hence reducing further spread of the disease by isolating and providing proper management to the patients with positive findings on HRCT. So here are the results. Out of 932 number of patients, 817 patients had RTPCR positive status and 115 patients had RTPCR negative status. Out of the 817 RTPCR positive status, 72.2% which is 594 patients had HRCT features positive and 223 which is 23.9% had HRCT features absent. 12.33 which is 115 patients out of total 932 patients had negative RTPCR status while HRCT status of these patients were positive. Patients with negative RTPCR and HRCT are excluded from the study. So in conclusion, in a study done on 932 patients, 115 patients with negative RTPCR status had CTSS score greater than 0, which is approximately 12.33% of the total. 12.3% patients are false negative with potential risk of spreading the infection. Out of the 932 patients, 817 patients were RTPCR positive and 115 were RTPCR negative. Out of 817 RTPCR positive patients, 594 patients showed features suggestive of COVID-19 on HRCT and 223 patients did not. HRCT along with RTPCR should be the modality of choice for screening of patients with symptoms like fever, cough, cold, sore throat, myalgia and gastrointestinal symptoms to rule out COVID-19 pneumonitis. According to the study done in Wuhan, China, chest CT has a high sensitivity for diagnosis of coronavirus disease 2019. CT chest may be considered as a primary tool for the current COVID-19 detection in epidemic areas. RTPCR, a technique as the name suggests, is a quantitative test based on the polymerase chain which detects the nucleic acid present in the SARS-CoV-2 virus present in the upper and mid respiratory tracts. RNA strand present in the SARS-CoV-2 virus is converted into DNA strand. Multiple copies of this DNA strand is made by adding chemical reagents in the PCR thermocycler machine within a few hours. Fluorescence emitted by the copies of the virus if present is detected by the machine and the result is demonstrated. The swab is taken from the oropharynx, nasopharynx with the latter being more sensitive. Sample is taken on 5th to 14th day of the onset of the symptoms. RTPCR can deliver results in 6 to 8 hours. HRCT takes approximately 15 to 20 minutes and demonstrates COVID-19 related changes immediately. COVID-specific changes which includes ground-class obesity seen in periphery, consolidation and fibrosis can confirm the diagnosis within a few minutes after acquiring images. Based on the involvement of the area of lung scoring is done. HRCT tested of the patient plays a very important role in diagnosis and deciding further management of the patient. RTPCR positive status alone is not a reliable for stratification, hospital administration and management of the patient. While RTPCR is cost-effective, HRCT chest is a quick and reliable method for diagnosis of COVID-19 pneumonitis. The radiation hazard of the HRCT should also be taken into consideration. The effective dose of one HRCT chest is approximately 5 to 7 millisieverts which is comparable to approximately 2 years of natural radiation. Here are my references. Thank you.