Chest imagingCase Type
Francesca Currò¹, Riccardo Pizzolato², Adrian Zdjelar², Marco Francesco Maria Cavallaro¹, Maja Ukmar¹, Maria Assunta Cova²Patient
47 years, male
A previously healthy 47 years old man presented to the emergency department with cough and high fever (38.5°C) for five days. At admission, oxygen saturation was normal (SpO2 99%) and laboratory tests showed leukopenia (3.99×10^3/μL, normal range 4.0-11×10^3/μL) and mild elevated c-reactive protein (20 mg/L, normal range <0.5 md/dl).
Initially, bedside chest X-ray didn’t show significative alterations and nasopharyngeal swab for COVID-19 was negative, therefore chest HRCT was performed due to the high clinical suspicion of SARS-CoV-2 infection.
Chest CT showed unilateral crazy paving pattern on the right lower lobe, consistent with interstitial pneumonia. COVID-19 was then confirmed through RT-PCR of bronchoalveolar lavage.
The first chest X-ray performed at bedside in the emergency room didn’t demonstrate definitive alterations (Fig.1). Chest HRCT performed 6 hours later showed a wide area of crazy paving pattern in the posterior region of the lower right lobe (Fig.2); there were no parenchymal alteration on the left lung, bilateral lung effusion nor mediastinal nodal enlargement. The second chest X-ray performed 3 days later showed small bilateral basal consolidations (Fig.3).
Coronavirus disease 2019 (COVID-19) is a highly infectious respiratory syndrome caused by a novel coronavirus called SARS-CoV-2, that was first identified in Wuhan (China) in December 2019 . The virus has spread rapidly worldwide causing thousands of deaths and on 11th March 2020, the World Health Organization confirmed COVID-19 as a pandemic. Actually a serious cluster of COVID-19 is reported in the North of Italy and in the country as the 27th March 80539 total cases with 8165 deaths were confirmed .
The common symptoms of COVID-19 are fever, fatigue, dry cough and dyspnoea; lymphopenia and elevated PCR are typical findings at laboratory. It is reported that the average incubation period of the infection is 6.4 days . The diagnosis is based on reverse transcription-polymerase chain reaction (RT-PCR) or gene sequencing of sputum, throat swab or lower respiratory tract secretions. It is emerging that chest CT, thanks to its high sensitivity (98%), could play a critical role in the diagnosis of COVID-19 at the early stage of infection when chest X-ray is often negative or in patients with negative RT-PCR results but high clinical suspicion of infection .
A Chinese retrospective study conducted on 21 patients with COVID-19 reported that on chest CT 71% of cases presented bilateral involvement, 57% ground-glass opacities, 33% rounded opacities, 33% peripheral distribution, 29% consolidation with ground-glass opacities and only 19% of the patients presented crazy-paving pattern .
In our case HRCT showed a unilateral crazy paving pattern with ground-glass opacity superimposed by interlobular and intralobular septal thickening, resembling irregular paving stones. It could be considered the result from the alveolar oedema and interstitial inflammatory of acute lung injury  and, although is less frequent than ground-glass opacities, it must be considered as suggestive for COVID-19, entering progressive or peak stage .
The patient was hospitalized for two weeks in our Hospital and then discharged for resolution of symptoms.
Chest HRCT, thanks to its high sensitivity, is a useful tool for COVID-19 diagnosis in patients with clinical suspicion of infection but with negative microbiological tests. Therefore, it is necessary to become familiar with the typical and atypical CT manifestations of COVID-19 and it is important to highlight that during this pandemic also unilateral consolidations must be considered with suspicion for Sars-Cov-2 infection.
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 A. Patel, D.B. Jernigan et al. 2019-nCoV CDC Response Team, Initial public health response and interim clinical guidance for the 2019 novel coronavirus outbreak -United States, December 31, 2019-February 4, 2020. MMWR Morb Mortal Wkly Rep. 2020 Feb 7;69(5):140-146 (PMID: 32027631)
 Zheng Ye, Yun Zhang, et al. CT manifestations of new coronavirus disease 2019 (COVID-19): a pictorial review. European Radiology 2020 Mar 19 (PMID: 32193638)
 Michael Chung et al. CT Imaging Features of 2019 Novel Coronavirus (2019-nCoV), Radiology 2020 Apr; 295(1):202-20 (PMID: 32017661)
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