An institutional based study on imaging conundrum of newly diagnosed coronavirus disease 2019 (Covid-19) – a retrospective analysis in India population

Abstract

Introduction: Coronavirus disease-2019 (COVID-19) was announced as a pandemic by the World Health Organization (WHO) on March 11, 2020. According to a WHO report on COVID-19, the disease has nospecific manifestation and the patient's pres-entation can range from completely asymptomatic to severe pneumonia and death. Objective: To retrospectively characterize and interpret the spectrum of chest computed tomography (CT) imaging features of Coronavirus disease-19 (COVID-19) in infected Indian population and to correlate CT total severity score with clinical classification and study extra-pulmonary manifestation of Corona-virus disease 2019 (COVID-19). Methods: A retrospective single-centre study was conducted on patients with COVID-19 from May 10, 2020, to July 13, 2020, in tertiary care Max super specialty hospital, Delhi, India. A total of 532 patients either laboratory-confirmed or strongly suspected of having COVID-19 underwent CT chest and their imaging features were analyzed and interpreted in detail and studied for extra-pulmonary manifestation of COVID-19. The consistency of observers was evaluated for CT total severity score (TSS) and TSS was compared with clinical classification. Result: This study included 532 patients, 10 patients were excluded from the study. Among a total of 522 patients in the study, 362 (69.3%) were males and 160 (30.7%) were females with a mean age of 52.75 years (range 14-88). According to the clinical subtype classification there were mild 17 (3.3%), common 355 (68.0%), severe 105 (20.1%) and critical 45 (8.6%) cases. 57 (10.9%) patients died and 37 (7.08%) patients showed extra-pulmonary manifestation of COVID-19. There were 17 patients with normal CT chest. Only 2 cases had unilateral lung disease and the rest of 503 cases showed bilateral lung involvement with multiple opacities and multiple lobe involvement. Diffuse lung involvement i.e. white lung noted in 10 cases and none of the patient had single lesion. Opacities on CT imaging tended to be both peripheral and central in most cases, followed by purely peripheral and rarely are with the purely central distribution. According to CT attenuation of opacity, Ground glass opacity (GGO), and the mixture of Ground glass opacity & consolidative opacities and consolidative opacities was the dominant abnormality founded almost in all cases. Perilesional or intralesional, thickened small vessel was observed in almost all cases. Accompany-ing signs were crazy paving (40.6%), reverse halo sign (10.9 %), subpleural lines (47.9%), air bronchogram (28.4%), bronchiec-tasis (18.6%), pleural effusion (5.6%) and mediastinal lymphadenopathy (4.8%). Follow up scanning was obtained in 28 cases, showed no change in 2 cases, turned better in 12 cases, and became worse in 14 cases on follow up imaging studies. Conclusions: The typical pattern of COVID-19 pneumonia in Delhi, India, was ground glass opacity in the form of pure ground glass opacity, ground glass opacity with superimposed crazy paving pattern or Ground glass opacity admixed with consolidation with intralesional vascular enlargement were the most dominant lung parenchymal abnormalities with the peripheral and pos-terior distribution encountered in most of the cases. In the short term follow-up, more patients had disease progression rather than absorption. Proportion of patients [17 (3.2%)] with normal CT chest in laboratory-confirmed COVID-19 was relatively low; hence chest CT may play a complementary role in the early detection of COVID-19 pneumonia and could be regarded as a diagnotic standard of COVID-19. COVID-19 is progressive viral pneumonia with broad spectrum of clinical manifestations and can also present with extra-pulmonary manifestations .