Teaching Case

A 61-year-old male non-smoking patient presented with dyspnoea (respiratory rate 25/min, peripheral capillary oxygen saturation 67%) and fever (38.3°C). Apart from pre-existing arterial hypertension, there were no risk factors or known pathogen exposure.

Blood analysis showed normal leucocytes, elevated C-reactive protein (CRP) levels (106.3mg/l; normal range <5mg/l) and a normal procalcitonin level (0.12µg/l; normal range <0.50µg/l). Glomerular filtration rate was reduced (47ml/min). Reverse transcription polymerase change reaction (RT-PCR) for coronavirus disease-2019 (COVID-19) was positive, Influenza tests were negative.

As dyspnoea deteriorated, the patient was admitted to our intensive care unit. Under continuous invasive ventilation and broad-spectrum antibiotics CRP levels rose to 300mg/l and fever continued over the next 4 days. With the impending need of extracorporeal membrane oxygenation, a chest CT scan was performed.

Chest X-ray at initial presentation showed bilateral pulmonary consolidation in mid-and lower zones (Figs. 1a and b).  

Chest CT was performed using a 128-row multidetector CT with dose modulation and iterative reconstruction algorithm (iCT, Philips, Amsterdam, Netherlands). Images were acquired in the venous phase 70 sec after intravenous injection of 70 ml contrast agent (400 mg iodine/ml). Tube voltage was set at 100 kV, tube current ranged between 53 and 83 mAs. Axial images were reconstructed in 1 mm slices with multiplanar reformations.

CT images obtained 4 days after onset of symptoms revealed patchy and partially coalescing geographic ground glass opacities (GGOs) with a slight peripheral preponderance in the ventral parts of both lungs (Figs. 2a–f). Some areas of GGOs show a discreet crazy paving pattern (Figs. 2c, d). There was almost complete consolidation with positive air bronchograms in the dorsal parts of both lungs (mainly lower lobes with slightly reduced volume, Figs. 2a–c, f). Small bilateral pleural effusions were present (Fig. 2g). No thoracic lymphadenopathy was noted.

Here we present radiographic and CT images of a severe, laboratory-proven COVID-19 pneumonia in a 61-year old male patient. To our knowledge, this is one of the first imaging studies of this new airway disease published outside of China [1].

COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [2, 3]. Since the original outbreak in Wuhan, China, in December 2019, COVID-19 has spread over multiple countries around the world causing 167,511 infections and 6,606 deaths (as of 16 March 2020), with numbers outside of China still rapidly growing [4]. On 11 March 2020, the World Health Organization (WHO) announced the outbreak a pandemic.

The majority of our imaging findings are consistent with numerous previous publications on CT morphology of COVID-19 pneumonia: multifocal, mostly bilateral, patchy, band-like or even coalescent GGOs as well as consolidations and crazy paving appearance have been described before, the latter two indicating a severe disease manifestation [5–9]. The extensive consolidation of the dorsal aspects of both lungs (mainly lower lobes) with preserved air bronchogram, however, is uncommon for COVID-19. Consolidations in COVID-19 are usually more localised, patchy or crescent-shaped [6]. The extensive consolidations in our case may be at least in part due to bacterial coinfection (despite antibiotic treatment) or preceding invasive ventilation in supine position over several days. The slight volume loss of the lower lobes and the fact that the patient’s pulmonary function improved after he was turned into prone position following the CT-scan support the latter assumption. We would expect coalescent GGOs and crazy paving as in the ventral parts of the lung if aeration was more equally distributed.

The role of CT in diagnosis and management of COVID-19 is not yet clear. In early detection of COVID-19, CT has shown higher sensitivity compared to RT-PCR (97% vs. 60%) [10]. On the other hand, some publications indicate that also CT may be false-negative in detecting very early disease stages [9, 11]. In the present case, CT was not employed to diagnose the disease, but to exclude possible concomitant pathology like a pleural empyema, to evaluate disease extent objectively and to help optimise the therapeutic strategy. In this scenario, CT may become even more valuable with rising numbers of COVID-19 patients and limited isolation, intensive care and ventilation capacities. Moreover, it may guide possible future antiviral treatment options.

In conclusion, the present case illustrates a typical appearance of severe COVID-19 pneumonia requiring invasive ventilation. CT may be a useful tool not only for early diagnosis, but also for evaluation of disease extent and treatment planning in advanced stages.

Written patient consent for this case was waived by the Editorial Board. Patient data may have been modified to ensure patient anonymity.