Comparative Study of HRCT Imaging Characteristics of Psittaci Pneumonia and COVID-19 Pneumonia (preprint)

ABSTRACT

Backgroud Both Chlamydia psittaci and COVID-19 virus can cause lung inflammation, which manifests extremely similarly in clinical symptoms and imaging. Especially during the epidemic of COVID-19, psittacosis pneumonia is easily misdiagnosed as COVID-19 pneumonia. The identification of the chest imaging between the two diseases is of special significance when the epidemiological contact history is unclear, and the etiology and nucleic acid test results are not available. This study conducts to compare the imaging characteristics on chest high-resolution CTs (HRCT) between patients with psittaci pneumonia and COVID-19 pneumonia. Methods: A retrospective analysis of the imaging characteristics on chest HRCTs of 10 psittaci pneumonia patients and 13 COVID-19 pneumonia patients. The similarities and differences in HRCT images of patients with psittaci pneumonia and COVID-19 pneumonia were analyzed. Results: HRCT showed that among the 10 psittaci pneumonia patients, 8 cases (80.00%) had single lobe involvement, and 2 cases (20.00%) had multiple lobe involvement. Among the 13 COVID-19 pneumonia patients, 2 cases had single lobe involvement (15.38%), and 11 cases had multiple lobe involvement (84.62%). The types of lesions in 10 psittaci pneumonia patients included simple consolidation in 5 cases (50.00%), and ground-glass opacity (GGO) with consolidation in 5 cases (50.00%). The types of lesions in 13 COVID-19 pneumonia patients included simple GGO in 6 cases (46.15%), GGO with consolidation in 4 cases (30.77%), GGO with paving stone sign in 2 cases (15.38%), and simple consolidation in 1 case (7.69%). Lymphadenopathy was observed in 1 psittaci pneumonia patient (10.00%) and 1 COVID-19 pneumonia patient (7.69%). Among the 10 psittaci pneumonia patients, 8 cases (80.00%) had bronchial inflation, and 6 patients (60.00%) had pleural effusion. Among the 13 COVID-19 pneumonia patients, 5 patients (38.46%) showed signs of bronchial inflation, while no pleural effusion was observed in 13 patients. Conclusion: Chest HRCTs can distinguish COVID-19 pneumonia from psittaci pneumonia, and can provide early diagnoses of these two diseases.