Chest CT Scan In Patients With Contusion and COVID 19 A Comparative Study With Pure Lung Contusion

Resource allocation for traumatic patients who are positive/negative for COVID-19 challenges the diagnosis. This study aims to compare the chest CT of COVID-19 associated with lung contusion versus those with lung contusion only. CT-scans of 9 RT-PCR positive patients with lung contusion due to MVA (CC group) and 16 patients with lung contusions from pre-COVID-19 (CO group) were revaluated. The distribution and characteristics of presenting CT-scan findings; including presence, shape, distribution of GGO, consolidations, subpleural sparing, crazy-paving and Atoll sign. Presence of effusions and cavities were compared. Time course of the opacities was compared. Bilateral distribution of opacities was noted in 100% of CC and 87.5% of CO group. There was no significant difference between GGO or consolidation shapes (P=0.44 and P=0.66). Both GGO and consolidations were more diffusely distributed in CC, a predominantly peripheral distribution was more commonly seen in the CO group (P=0.03 and P=0.01). Subpleural sparing was noted in 93.8% of CO as compared to 44% of CC group (p=0.04). Time to resolution was significantly longer in CC (15±6days) comparing to CO patients (P=0.02). 'Typical' chest CT findings including bilateral peripheral GGO and consolidations, crazypaving, Atoll signs and also less typical findings e.g. subpleural sparing is seen in lung contusion and COVID-19 pneumonitis. Lesion Time course might be a better radiologic discriminator between the two entities.