CT Imaging Evolution of Novel Coronavirus Pneumonia during Hospitalization

Object: To evaluate CT Features on serial thin-section computed tomographic (CT) scans in patients with conventional Novel Coronavirus Pneumonia (COVID-19) for the period during which they remained hospitalized. Methods: In this Retrospective study, we collected clinical information including Laboratory investigations and more importantly we focused on collecting imaging data of these 15 selected patients (8 men and 7 women, 22 - 70 years old, average age (45 ± 15)) with COVID-19 disease. The mean time between the initial and repeat thin-section CT scans was 3.3 ± 2.1 days, 7.9 ± 2.1 days, 14.2 ± 1.3 days after onset of symptoms in these 15 patients. Three experienced Radiologists reviewed the CT images independently and also in collaboration with each other for complicated or unique cases, for the Imaging characteristics like number and site of lesions, distribution of lesions whether it is lobular, lobar, unilateral or bilateral, and comparing the severity of disease in relation to the CT findings. The CT features were compared using the χ2 test and Fisher’s exact probability. Results: All of 15 patients had a history of visit to the endemic center i.e. Wuhan city or came in direct contact with an infected individual. Fever (93.3%) was the most common symptom. Majority of patients had a normal white blood cell count, and normal lymphocyte count although there were patients with leucopenia and lymphocytopenia. CT images showed predominate Ground-Glass opacities in the initial and repeat CT scans with a percentage of 90.6%, 53.9%, 44.2% respectively during the three spaced CT examinations;most patients had bilateral lung involvement (60%, 93.3%, 93.3%), the lesions predominantly involved the posterior (87.5%, 71.9%, 76.6%) and peripheral (90.6%, 84.3%, 85.7%) part of the lungs. There were more consolidation and mixed patterns in repeat CT scan Versus initial CT scan, the difference was statistically significant (P-values were < 0.001). The total lung severity score in the three aforementioned timely spaced CT scans were 36 (3.3 ± 2.1 days) 63 (7.9 ± 2.1 days), and 57 (14.2 ± 1.3 days) respectively. The median percentage of pneumonia lesions of the whole lung volume in three times CT scan was 1.69% (4.59), 3.47% (5.46), 2.33% (4.75) respectively. Besides, “Tree-in-bud” sign, lung cavitation, and lymphadenopathy were absent. Conclusion: The Thin-slice Section CT Imaging features show uniquely different characteristics, each time the scans are taken. The most common findings in our study were bilateral multiple peripheral and mostly posterior ground-glass opacities (GGO), however the CT scan images that were taken in a timely manner to follow up demonstrated some remarkable changes, which undoubtedly play an important role in the diagnosis and management of the patient with COVID-19 disease.