Study population
Patients’ data were collected from seven isolation Iraqi hospitals in Erbil, Baghdad, Babylon, Al-Muthanna, Najaf, and Karbala provinces, between March 10 and April 5, 2020. Ninety-six (61 males and 35 females) with proven COVID-19 infection were enrolled in this study; aged 19–82 years, with a mean age of 49.3 ± 8.3 years. All patients were symptomatic, presented with variable degrees of fever, cough, and dyspnea. The patients were divided into two groups according to the duration of symptoms, the first group (70 patients) scanned within the first week of presentation while the second group (26 patients) scanned in the second week. The COVID-19 infection was confirmed using the RT-PCR test.
Inclusion criteria
Proved COVID-19 infection: patients with positive PCR.
Symptomatic patients presented with a variable degree of fever, cough, and dyspnea.
Exclusion criteria
Patients with preexisting lung disease were excluded from the study.
Study design
This study is a retrospective cross-sectional study.
Ethics approval and consent to participate
No individual data were included in the study.
The Research Ethics Committee of the Faculty of Medicine at Tikrit University - Iraq, approved this study.
All patients included in this study gave verbal informed consent to participate in this research. If the patient was unconscious at the time of the study, their next of keen have given written informed consent.
Verbal consent is advised by our medical research ethics committee, particularly in such unusual risky situation to reduce the risk of transmission of the disease by avoiding any unnecessary contact with the positive patients.
CT scanning protocol
A high-resolution CT (HRCT) scan was performed in all patients with 64-slice multi-detector row CT scanners (Siemens Sensation-64, Philips Brilliance-64, and GE LightSpeed-64). Patients were scanned in the supine position; head first, during breath-hold. Scanning parameters were tube voltage 100−120 kV, tube current 110−280 mA, pitch 1.375, FOV 350−400 mm. The 1.25-mm or 2.5-mm-thick images were reconstructed using a high-frequency reconstruction algorithm. All examinations were non-enhanced and no intravenous contrast medium was administered.
HRCT image analysis
Two expert radiologists (more than 5-years experience) have evaluated the CT images separately to identify the pulmonary changes. A detailed evaluation of the images was done and pulmonary changes were identified included ground-glass opacity (GGO), consolidation, crazy paving, tree-in-bud, broncho-vascular thickening, bronchiectasis, pulmonary nodules, cavitation, and pleural effusion. The distribution of pulmonary changes was furthermore identified as unilateral vs. bilateral and central vs. peripheral distribution. Lobar distribution was reported as upper, middle/lingular, lower, and multi-lobar distribution (two or more lobes).
Lung changes were identified as peripheral if limited to the outer one-third and central when confined to the inner two-thirds of the lung. Diffuse changes when both peripheral and central zones were affected simultaneously. If there was disagreement concerning the CT analysis, a third radiologist was consulted.
Statistical methodology
Statistical analysis was performed using SPSS 22.0. Measurement data were expressed as mean ± standard deviation, and numerical data are described as frequency. Patients were divided into two groups according to the duration of symptoms. Statistical analysis was done using ANOVA for chi-square calculation to test the significance of results regarding the CT findings across the groups, and the difference was statistically significant with a p value < 0.05.