We comprehensively analyzed the CT features of 67 patients confirmed with COVID-19 pneumonia in Hainan, an island in the south of China. We detailed described the epidemiologic and clinical features in these patients. Since most of the infected people in our study were imported cases or had close contact with infected patients. Our study provides further evidence of person-to-person transmission in COVID-19 [6, 7]. CT manifestation is helpful in early diagnosis of the COVID-19 and valuable for monitoring the disease evolution.
Consistent with recent studies[8, 9], our study found that the clinical features of COVID-19 infected patients resemble to that of SARS-CoV, with fever and cough most commonly seen. Gastrointestinal symptoms were uncommon seen, which differed from SARS-CoV, MERS-CoV, and seasonal influenza [10, 11]. We should not neglect the fact that some patients (7%) might be asymptomatic at the early course of the disease. Our findings provide further supported the notion that the diagnosis of infection could not be ruled out in those patients without clinical symptoms. For the asymptomatic persons with a clear history of exposure to COVID-19, medical observation, home isolation, and further examination should be considered. Besides, we found lymphopenia in 52% of the cases, which was consistent with the results of two recent reports[7, 9].
The confirmed cases with COVID-19 is still rapidly increasing across the world. Plain chest CT can discover lung lesions with high sensitivity , which is beneficial for early diagnosis and timely treatment. Our findings revealed some common CT imaging manifestations in patients confirmed with COVID-19 infection: bilateral, multifocal ground glass opacities, with subpleural distribution. Particularly, the lower lobes were the most affected lobes. Pleural effusion, pericardial effusion, cavitation, and lymphadenopathy were uncommon seen in these patients.
The most typical CT findings of COVID-19 is ground glass opacities. A recent pulmonay pathology study of COVID-19 revealed bilateral diﬀuse alveolar damage with cellular fbromyxoid exudates in the lung . Therefore, we deduce that the ground glass opacities might be associated with the diﬀuse alveolar damage including the pulmonary edema, since CT findings reflect the pathogenesis of viral infection. COVID-19 is a family member of Coronaviridae. Recent studies found that the pathological features of COVID-19 are similar to those seen in SARS and Middle Eastern respiratory syndrome (MERS) coronavirus infection . Thus, it is not surprising that the imaging features of COVID-19 resembles to that of SARS-CoV and MERS-CoV infection. In our study, a majority of patients showed bilateral multifocal involvement, which is fitted well with previous studies . SARS and MERS patients are tended to have unilateral involvement [15, 16]. More researches should be done to clarify whether this feature is specific to the COVID-19.
The follow-up CT scan showed that 3 of 7 patients who had negative CT findings at baseline scan, gradually progressed into unilateral ground glass opacities. Incubation period after infection with the COVID-19 may exist, a patient may be asymptomatic and CT could not detect any abnormalities at this time. At this stage, real-time PCR is crucial for the diagnosis of COVID-19 infection. Similarly, CT could be used to evaluate the disease evolution.
Of note, a few patients in our study had bilateral ground glass opacities in chest CT scans but with negative nucleic acid test for COVID-19. After twice of more times of nucleic acid tests, these patients were finally confirmed with by COVID-19 infection by real-time PCR. When this circumstance occurs, patient’s epidemic history, clinical symptoms, imaging features, along with laboratory tests are essential in the diagnosis of the disease. Also, for the patient had negative nucleic acid test but with epidemic history, home isolation is necessary.
CT findings during follow-up is closely with clinical outcomes. In this study, 65 patients had CT follow-up. Five patients had stable CT findings during follow-up, 22 patients showed disease resolution and 34 patients showed progression at first and resolved later all discharged from hospital later. CT scan could be effectively monitoring the disease evolution. Unfortunately, one patient with CT progression died. Two patients did not have CT follow-up because of sever condition and they died about 10 days after admission into the hospital. In conclusion, we found the CT findings fitted well with the clinical outcomes.
Our study had several limitations. Firstly, the sample size is relatively small. Second, most of the patients are imported cases. The difference between imported cases and local cases have not yet been clarified. Third, most of the patients presented with mild symptoms and they had a favorable outcome finally. Thus, our study could be considered preliminary.