Pattern And Distribution of Lung Findings on Chest CT and Severity Score  in COVID-19 Patients Attended at National Referral Hospital in Tanzaniaia

Abstract

Background: Chest computed tomography is an important imaging modality for assessing pulmonary involvement and disease severity in COVID-19, particularly where access to reverse transcription polymerase chain reaction testing is limited. Data on chest CT findings among COVID-19 patients in Tanzania, however, remain scarce. Objective: The objective of this study was to describe the pattern and distribution of pulmonary abnormalities on chest CT in adults with COVID-19, quantify disease severity using a CT severity score, and examine relationships with clinical and laboratory parameters. Methods: This was a hospital-based study of 158 adult COVID-19 patients (aged ≥18 years) referred for chest CT at Muhimbili National Hospital, Tanzania, from December 2019 to June 2022. CT images were acquired on 64- or 128-slice multi-detector scanners using a standard non-contrast protocol. CT severity scores, assigned out of 25 based on the percentage area involved in each lobe, were graded as mild (0–10), moderate (11–15), or severe (16–25). Associations between clinical and laboratory variables and CTSS were analyzed using chi-square tests; p<0.05 was considered significant. Results: The mean age was 53.67 ± 19.98 years (range 18–95); 63.92% were male and 43.03% were aged 60 years or older. Dyspnoea was the commonest presenting symptom (85.44%). All patients had abnormal scans. Bilateral involvement was seen in 91%, ground-glass opacities in 89%, peripheral distribution in 73%, and multilobar disease in 74%. Severe CTSS predominated (56.33%). Oxygen saturation below 95% was strongly related with severe findings (87.34%, p<0.001). RT-PCR was positive in 101 patients (63.92%). Notably, those without available RT-PCR results more often had severe CTSS than RT-PCR-positive patients (73.68% vs. 46.53%, p = 0.031). No significant relationship was found between CTSS and inflammatory markers. Conclusion: COVID-19 was frequent in older, male patients presenting clinically with difficulty in breathing. Most patients had severe CTSS. The distribution Pulmonary involvement in COVID-19 was predominantly bilateral, peripheral, and multilobar, with ground-glass opacities the most frequent finding. Moreover, CTSS showed a positive relationship with difficulty in breathing and abnormal oxygen saturation. Chest CT is a valuable adjunct for diagnosis and severity stratification, particularly where RT-PCR testing is constrained Keywords: COVID-19; chest computed tomography; CT severity score; ground-glass opacity; pneumonia.