Spectrum of chest computed tomographic (CT) findings in coronavirus disease-19 (COVID-19) patients in India

Abstract

Purpose: To report the spectrum of chest computed tomographic (CT) imaging findings in coronavirus disease-19 (COVID-19) infected Indian patients.

Methods: This was a prospective descriptive study comprising 147 consecutive reverse transcriptase polymerase chain reaction (RT-PCR) positive patients who underwent CT chest. Prevalence, distribution, extent and type of abnormal lung findings were recorded.

Results: Among the total study cohort of 147 patients, 104 (70.7 %) were males and 43 (29.3 %) were females with mean age of 40.9 ± 17.2 years (range 24-71 years). We observed lung parenchymal abnormalities in 51 (34.7 %) cases whereas 96 (65.3 %) RT-PCR positive cases had a normal chest CT. Only 12.2 % of the patients were dyspneic, 6.1 % had desaturation, 7.4 % had increased respiratory rate and 10.9 % had comorbidities. Among the patients with abnormal CT findings bilateral 39/51 (76.5 %), multilobar (88.2 %) lung involvement with a predominant peripheral and posterior distribution was commonly observed. With regards to the type of opacity, ground glass opacity (GGO) was the dominant abnormality found in all 51 (100 %) cases. Pure GGO was observed in 15 (29.4 %), GGO with crazy paving pattern was seen in 15 (29.4 %) and GGO mixed with consolidation was noted in 21(41.2 %). Peri-lesional or intralesional segmental or subsegmental pulmonary vessel enlargement was observed in 36 (70.6 %) cases.

Conclusion: In this study population predominantly with mild symptoms and few comorbidities, two-thirds of RT-PCR positive patients had a normal chest CT; whereas the remaining patients showed typical findings of predominant GGOs with a bilateral distribution and peripheral predominance.

Keywords: COVID-19; CT; SARS-CoV-2.

Fig. 1

Flow chart depicting the result of chest CT in symptomatic RT-PCR confirmed SARS-CoV-2 infected patients along with the clinical outcome.

Fig. 2

Non-contrast axial chest CT images in the lung window setting of a 65-year old male COVID-19 positive patient, obtained 7 days after symptom onset, at the carinal (a), subcarinal (b), mid-basal (c) and basal (d) levels showing bilateral elongated, confluent ground glass opacities with pronounced peripheral and posterior distribution with interlobular septal thickening producing crazy-paving pattern with early progression to consolidation formation.

Fig. 3

Non-contrast axial chest CT images in lung window settings of a 40-year old male COVID-19 positive patient, obtained 8 days after symptom onset, in cranio-caudal sequence (a,b,c,d) showing multiple patchy peripheral predominantly posterior ground glass opacities with progression to consolidation in both lungs. There is also evidence of atoll sign in right lung (d) marked by black arrow and perilesional vessel enlargement in left lung (d) marked by black arrow with white border.

Fig. 4

Non-contrast chest CT axial image (a) in a 62-year old COVID-19 positive male patient, obtained 9 days after symptom onset, showing sub-pleural curvilinear lines (black arrow) with multiple reticulations in right lower lobe and mixed GGO-consolidation pattern in left lower lobe. Fig. 3b in a different 61-year old COVID-19 positive male patient, obtained 6 days after symptom onset, shows evidence of sub-pleural reticulations (black arrow) in the posterior segment of right upper lobe with a few rounded morphology GGOs in left upper lobe.

Fig. 5

Non-contrast axial chest CT images in lung window settings of a 62-year old male COVID-19 positive patient, obtained 5 days after symptom onset, showing diffuse ground glass opacities in peripheral and central distribution progressing to frank consolidation in Fig. 2b. There is also evidence of intralesional vessel enlargement (blue arrows in a & b) and bronchial dilatation (red arrow in b).