Radio-clinical mismatch in two patients positive for COVID-19

Patient 1: A 53-year-old male patient, with no past medical history, presented to the emergency room (ER) for nausea, fatigue and headaches, 10 days after an Evangelist meeting in Mulhouse (North-East of France). No fever, cough or any respiratory dysfunction was found.

Patient 2: A 75-year-old male patient, with history of tobacco use, diabetes and obstructive sleep apnoea, presented to the ER for new onset of cognitive impairment and confusion. The clinical exam revealed only bilateral crackles. The biological exam showed a mild hypokalaemia (2.3mmol/L).

Patient 1 underwent a contrast chest CT-scan six days after his admission which revealed bilateral consolidation predominantly basal and peripheral, with adjacent ground-glass opacities and crazy paving pattern. Less than 25% of the parenchyma was involved.

Patient 2 underwent a non-contrast chest CT-scan two days after his admission which revealed bilateral peripheral ground-glass opacities and consolidation. Sub-pleural intralobular reticulations with architectural distortion and traction bronchiectasis were found, involving approximately 50% of the parenchyma.

A.    Background
Coronaviruses are a broad family of enveloped RNA viruses. A new coronavirus has been identified through deep-sequencing and named SARS-CoV-2 (COVID-19) which is responsible of the current pandemic situation of pneumonia cases [1].
B.    Clinical Perspective
The typical presentation of COVID-19 pneumonia includes fever (in 98.6%), cough (76%) and myalgia or fatigue (44%) [1]. Currently, the gold-standard for diagnosis remains the detection of the virus by RT-PCR methods. The CT-scan could become soon the first line diagnostic tool because of its high sensibility (97%) and its relatively good NPV (83%) [2].
C.    Imaging Perspective
The main usual CT findings are bilateral ground-glass opacities, with basal and subpleural distribution. However, the CT has a low specificity (25%) compared to the RT-PCR [2]. Some findings may help to orientate the diagnosis of COVID-19 infection instead of other viral pneumonia based on the predominance of ground-glass opacities, peripheric and posterior distribution, reticulations, vascular thickening and the absence of lymphadenopathy and pleural effusion [3].
D.    Outcome
It is now known that because of its high sensitivity, CT-scans can show some abnormalities [4] even in asymptomatic patients, with signs of severity (such as traction bronchiectasis) [5,6]. However, most of the time, there is a good correlation between the clinical state of the patient and the CT findings [7-9]. Our two cases show that despite the unusual clinical presentation, the CT findings were alarming, with an extensive parenchymal involvement. However, the CT findings did not change the therapy planning, and because of good tolerance, the patients were discharged after introduction of hydroxychloroquine.  

E.    Take Home Message / Teaching Points
A mismatch between the symptoms and the CT findings can be found. We have to be aware of this possible mismatch, especially because of the high sensitivity of CT. However, the RT-PCR remains the gold-standard and we should not forget that we are first treating patients and not images. The main point should be the clinical state of the patient and his potential comorbidities, to avoid intensive care only based on CT findings.
Written informed patient consent for publication has been obtained.