Yield of Adding chest CT to Abdominal CT to Detect COVID-19 in Patients Presenting with Acute Gastrointestinal Symptoms (SCOUT-3): Multicenter Study.

Borgstein, A B J; Scheijmans, J C G; Puylaert, C A J; Keywani, K; Lobatto, M E; Orsini, R G; Veillinga, T van Rees; van Rossen, J; Scheerder, M J; Voermans, R P; Han, A X; Russell, C A; Prins, J M; Gietema, H A; Stoker, J; Boermeester, M A; Gisbertz, S S; Besselink, M G

OBTECTIVE To determine the incremental yield of standardized addition of chest CT to abdominal CT to detect COVID-19 in patients presenting with primarily acute gastrointestinal symptoms requiring abdominal imaging. SUMMARY BACKGROUND DATA Around 20% of patients with COVID-19 present with gastrointestinal symptoms. COVID-19 might be neglected in these patients, as the focus could be on finding abdominal pathology. During the COVID-19 pandemic several centers have routinely added chest CT to abdominal CT to detect possible COVID-19 in patients presenting with gastrointestinal symptoms. However, the incremental yield of this strategy is unknown. METHODS This multicenter study in six Dutch centers included consecutive adult patients presenting with acute non-traumatic gastrointestinal symptoms, who underwent standardized combined abdominal and chest CT between March 15, 2020 and April 30, 2020. All CT scans were read for signs of COVID-19 related pulmonary sequelae using the CO-RADS score. The primary outcome was the yield of high COVID-19 suspicion (CO-RADS 4-5) based on chest CT. RESULTS A total of 392 patients were included. Radiologic suspicion for COVID-19 (CO-RADS 4-5) was present in 17 (4.3%) patients, eleven of which were diagnosed with COVID-19. Only five patients with CO-RADS 4-5 presented without any respiratory symptoms and were diagnosed with COVID-19. No relation with community prevalence could be detected. CONCLUSION The yield of adding chest CT to abdominal CT to detect COVID-19 in patients presenting with acute gastrointestinal symptoms is extremely low with an additional detection rate of around 1%.