Clinicoradiological course in coronavirus disease-19 (COVID-19) patients who are asymptomatic at admission

BJR Open. 2020 Jul 31;2(1):20200033. doi: 10.1259/bjro.20200033. eCollection 2020.


Objective: The study aimed to describe the clinical and imaging course of reverse transcriptase polymerase chain reaction) confirmed coronavirus disease (COVID-19) patients who are asymptomatic at admission.

Methods: This was a retrospective observational study. Severe acute respiratory syndrome coronavisrus-2 (SARS-CoV-2) positive cases that were asymptomatic at admission were retrospectively enrolled. Specific clinical information, laboratory test results, chest CT imaging features and outcome data during hospital stay were collected and analyzed.

Results: 137 non-consecutive asymptomatic patients with reverse transcriptase polymerase chain reaction confirmed COVID-19 were enrolled in the present study. On admission, patients had no symptoms but chest CT findings were present in 61/137 (44.5%). Ground glass opacity (48, 78.7%) followed by ground glass opacity with crazy-paving pattern (9, 14.7%) were the commonest type of opacities with posterior, peripheral predominance and lower zone predilection. Among the initial CT positive group of 61 patients, follow-up imaging revealed progression of pulmonary opacities in 13/61 (21.4%), complete resorption in 21/61 (34.4%), partial resolution in 22/61 (36%) and no change in 5/61 (8.2%). The patients in progression group (54 ± 19.7 years) were older and had higher frequency of co-morbidities (46.2%) compared to the other three groups (10.4%). The patients in progression group had a significantly higher C-reactive protein, higher lactate dehydrogenase and lower lymphocyte count than the other groups (all p-values < 0.05). The duration of hospital stay was longer in the progression group (27.1 ± 11.4 days) compared to the other three groups (16.12 ± 5.8) (p =< 0.05).

Conclusion: Nearly half of the asymptomatic cases with confirmed COVID-19 had abnormal chest CT imaging. Asymptomatic infections can have a variable clinicoradiological course. Clinically, some recover without developing symptoms, some present few mild symptoms whereas some deteriorate. Similarly, imaging follow-up may reveal resolution (partial or complete), progression or no change.

Advances in knowledge: Clinicoradiological course of asymptomatic COVID-19 cases is diverse.