Quantitative longitudinal imaging findings of a severe unilateral COVID-19 associated with other types of pneumonia

A 44-year-old male patient with a history of indirect contact with Wuhan people in China，presented with 4 days fever, cough, sputum, and shortness of breath, his axillary temperature was fluctuated from 37.5 to 40℃, and then he was admitted to our hospital on day 5. Laboratory studies showed decreased white blood cell counts (2.25*10⁹/L), decreased neutrophil counts (1.70*10⁹/L), decreased lymphocyte counts (0.37*10⁹/L), and increased C-reaction protein (CRP, 65.58 mg/L).

The chest CT examinations on day 5 and day 7 showed that the infected lesion on right lung mainly presented as mixed ground glass opacity and consolidation with fine reticulation (Fig. 1a), thickened vessels (Fig. 1b) within the lesion. The third chest CT examination on day 10 showed that the old lesion progressed, and a new lesion appeared on the right lower lobe of the ipsilateral lung. The bronchial wall within the lesions was thickened (Fig. 1c), and air bronchogram and serrated margin can be observed in a curved planar reconstruction image (Fig. 1d). The progress of the infected unilateral lesions and pulmonary involvement was demonstrated in Figure 2. Comparing with quantitative measurement results on day 5, the lesions’ volume and lesions’ volume change on day 10 increased by 357% and 18.8%, respectively (Figure 3).

Background

A novel coronavirus, which can be transmitted from person to person, is mainly manifested by novel coronavirus pneumonia (NCP). The virus was named as severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) [1], and the caused disease was designated as coronavirus disease 2019 (COVID-19) [2] by World Health Organization in February 2020. The disease is highly contagious with a basic infectivity of 2.2 person-times [3].

Clinical Perspective

The typical clinical manifestations of COVID-19 include fever, cough and myalgia [4], severe patients may develop dyspnoea, lymphopenia and/or hypoxemia several days later and progress rapidly to acute respiratory distress syndrome. According to the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia (Trail Version 7) released by the Chinese government in March 2020 [5], one of the diagnostic criteria for COVID-19 is to test real-time fluorescent RT-PCR for new coronavirus nucleic acid for suspected patients. In early stage with mild NCP symptoms, chest CT can be an important complement to negative RT-PCR because of its high sensitivity (97%) for diagnosis of COVID-19 [6], while CT is not specific for COVID-19, confirmation by RT-PCR testing is still required.

Imaging Perspective

All the COVID-19 patients had abnormalities in chest CT images, and the typical imaging findings include unilateral or bilateral ground-glass opacities (GGO), consolidation, mixed GGO and consolidation, bronchial wall thickening, and vascular enlargement [7]. NCP should be distinguished from other known viral pneumonia and mycoplasma pneumoniae infections. However, the patient we introduced in this study also presented as mycoplasma pneumonia, gram-positive bacterium positive (++) and gram-negative bacterium (+) according to laboratory studies, clinical symptoms, serological test and CT imaging findings, thus result in a unilateral consolidation as the primary imaging manifestation and progressed within ipsilateral lung.

Outcome

The patient was transferred to the isolation ward for the novel coronavirus quarantine, and the nasopharyngeal swab test was positive which confirmed the infection of SARS-CoV-2. Quantitative CT analysis can give objective and direct results on the extent of disease progression in the course of disease diagnosis and treatment, and it is very important to guide clinical medication. After supportive treatment with ceftriaxone and moxifloxacin for antibacterial treatment, and recombinant human interferon(α1b), ganciclovir and lopinavir/ritonavir for antiviral treatment, the patient recovered gradually, his final chest CT examination revealed lesion absorption and fibrosis, then the patient was discharged from hospital.

Take-Home Message/Teaching points

The severe COVID-19 patient presented some Atypical imaging manifestations. Only unilateral lung was infected throughout the course, and the lung parenchyma and bronchus were affected simultaneously due to the mixed infection. Quantitative dynamic CT images of the chest can longitudinally monitor the disease progress of COVID-19 patient.

Written informed patient consent for publication has been obtained.