Clinical and computed tomographic imaging features of novel coronavirus pneumonia caused by SARS-CoV-2

Abstract

Purpose: To investigate the clinical and imaging characteristics of computed tomography (CT) in novel coronavirus pneumonia (NCP) caused by SARS-CoV-2.

Materials and methods: A retrospective analysis was performed on the imaging findings of patients confirmed with COVID-19 pneumonia who had chest CT scanning and treatment after disease onset. The clinical and imaging data were analyzed.

Results: Fifty patients were enrolled, including mild type in nine, common in 28, severe in 10 and critically severe in the rest three. Mild patients (29 years) were significantly (P<0.03) younger than either common (44.5 years) or severe (54.7) and critically severe (65.7 years) patients, and common patients were also significantly (P<0.03) younger than severe and critically severe patients. Mild patients had low to moderate fever (<39.1 °C), 49 (98%) patients had normal or slightly reduced leukocyte count, 14 (28%) had decreased counts of lymphocytes, and 26 (52%) patients had increased C-reactive protein. Nine mild patients were negative in CT imaging. For all the other types of NCP, the lesion was in the right upper lobe in 30 cases, right middle lobe in 22, right lower lobe in 39, left upper lobe in 33 and left lower lobe in 36. The lesion was primarily located in the peripheral area under the pleura with possible extension towards the pulmonary hilum. Symmetrical lesions were seen in 26 cases and asymmetrical in 15. The density of lesion was mostly uneven with ground glass opacity as the primary presentation accompanied by partial consolidation and fibrosis.

Conclusion: CT imaging presentations of NCP are mostly patchy ground glass opacities in the peripheral areas under the pleura with partial consolidation which will be absorbed with formation of fibrotic stripes if improved. CT scanning provides important bases for early diagnosis and treatment of NCP.

Keywords: Computed tomography; Covid-19; Imaging finding; Novel coronavirus pneumonia; SARS-CoV-2.

Fig. 1

Mild novel coronavirus pneumonia in a 13-year-old man who had intermittent fever for three days before admission. Plain computed tomographic scan of the lung (A, axial plane, and B, coronal plane) in the lung window showed no obvious abnormality in the lungs.

Fig. 2

Common novel coronavirus pneumonia in a 37-year-old man with fever for six days and cough for two days before admission. A. Axial plane of computed tomography scan in the lung window showed multiple irregular pieces (arrows) of ground glass opacity under the pleura with consolidation (bigger arrow) and thickened interlobular sept in the right upper lobe. B. Seven days after treatment, the extent of the lesions decreased with fibrosis formation. C. Ten days after treatment, the extent of disease further shrank with decreased density. D. Axial plane in the mediastinal window revealed a small amount of pleural effusion (arrow).

Fig. 3

Common novel coronavirus pneumonia in a 46-year-old man with intermittent fever for five days before admission. A&B. Computed tomography pulmonary scan in the axial (A) and coronal (B) plane demonstrated a piece of ground glass opacity (arrow) under the pleura in the right lower lobe. C. Four days after treatment, the extent of lesion (small arrow) was decreased but with increased density, and a new lesion (bigger arrow) appeared in the left lower lobe with air bronchogram inside. D. Eleven days later, the extent of disease in both lungs shrank further and became consolidated with thickened interlobular septa.

Fig. 4

Severe novel coronavirus pneumonia in a 34-year-old man with fever and cough for ten days before admission. A&B. Computed tomography axial (A) and coronal (B) plane revealed multiple lesions of ground glass opacity, consolidation and fibrosis with symmetrical distribution in bilateral lungs, with the lesion extending towards the pulmonary hilum. Air bronchogram was observed within the lesion. C&D. Four days after treatment, the extent of lesion shrank with decreased density and formation of fibrosis.

Fig. 5

Severe novel coronavirus pneumonia in a 48-year-old man with fever for seven days before admission. A&B. Computed tomography axial (A) and coronal (B) plane revealed multiple lesions (arrows) of ground glass opacity accompanied with consolidation under or near the pleura in bilateral lower lobes, with air bronchogram and thickened interlobular septa. A large piece of ground glass opacity (square box) could also be seen in the right lower lobe (B). C&D. Seven days after treatment, the right lesion was significantly reduced with formation of fibrotic stripes, and the left lesion was also absorbed with decreased density like ground glass opacity (arrow in C). E&F. Ten days after treatment, bilateral lesions were mostly absorbed with only some nodules and stripes of fibrosis left (arrows).

Fig. 6

Critically severe novel coronavirus pneumonia (NCP) in a 50-year-old woman with fever, cough, dizziness and fatigue for five days before admission. A&B. Computed tomography axial (A) and coronal (B) plane revealed multiple lesions of ground glass opacity accompanied with consolidation. The lesions extended towards the pulmonary hilum and had air bronchogram and thickened interlobular septa. C&D. Five days after treatment, the extent of disease shrank with decreased density but stripes of fibrosis.