CASE 16755 Published on 28.05.2020

Unilateral crazy paving pattern in a healthy man with COVID-19 infection


Chest imaging

Case Type

Clinical Cases


Francesca Currò¹, Riccardo Pizzolato², Adrian Zdjelar², Marco Francesco Maria Cavallaro¹, Maja Ukmar¹, Maria Assunta Cova²

¹ Department of Radiology, Ospedale Maggiore, Piazza dell’Ospitale 1, 34129 Trieste, Italy


² Department of Radiology, Ospedale di Cattinara, Strada di Fiume 447, 34149 Trieste, Italy


47 years, male

Area of Interest Lung ; Imaging Technique CT
Clinical History

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).

Imaging Findings

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 [1]. 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 [2].

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 [3]. 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 [4].

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 [5].

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 [4] and, although is less frequent than ground-glass opacities, it must be considered as suggestive for COVID-19, entering progressive or peak stage [6].  
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.

Differential Diagnosis List
COVID-19 pneumonia with crazy- paving pattern
COVID-19 pneumonia
Bacterial pneumonia
Acute respiratory distress syndrome (ARDS)
Final Diagnosis
COVID-19 pneumonia with crazy- paving pattern
Case information
ISSN: 1563-4086