Ultra-low-dose chest CT performance for the detection of viral pneumonia patterns during the COVID-19 outbreak period: a monocentric experience

Joël Greffier (1) , Adel Hoballah (1) , Alexandre Sadate (1) , Fabien De Oliveira (1) , Pierre-Geraud Claret (1, 2) , Hélène De Forges (3, 1) , Paul Loubet (1, 4) , Jean-Marc Mauboussin (5) , Aymeric Hamard (1) , Jean-Paul Beregi (1, 2) , Julien Frandon (1)

1 CHU Nîmes - Centre Hospitalier Universitaire de Nîmes
2 IMAGINE - Initial MAnagement and prevention of acute orGan failures IN critically ill patiEnts
3 ICM - Institut régional de Cancérologie de Montpellier
4 VBMI - Virulence bactérienne et maladies infectieuses
5 CHU Nîmes - Hôpital Universitaire Carémeau [Nîmes]

Background: Ultra low dose chest computed tomography (CT) acquisitions have been used for selected emergency room patients with acute dyspnea or minor thoracic trauma. The purpose of this study was to evaluate the diagnostic performance of ultra-low-dose (ULD) chest CT for detecting viral pneumonia patterns compared to standard (STD) dose chest CT. Methods: All consecutive adult patients with two non-enhanced chest CT acquisitions, one STD and one ULD, for suspicion of viral pneumonia between March 5th and April 2nd 2020 were included. CT results were divided into two groups: non-viral pneumonia CT or compatible with viral pneumonia CT based on viral pneumonia CT patterns: ground-glass opacity (GGO), consolidation, crazy paving, air bronchogram signs and fibrous stripes. The diagnostic performance of ULD CT for suspicion of viral pneumonia was evaluated. For CTs compatible with viral pneumonia, CT pattern detection on ULD CT was assessed and STD CT was used as a reference. Results: The study included 380 patients with 97 CTs (25.5%) compatible with viral pneumonia. The mean effective doses (EDs) were 1.66 (1.29; 2.18) mSv for STD and 0.20 (0.18; 0.22) mSv for ULD CT (P<0.001). The sensitivity and specificity of ULD CT for viral pneumonia detection were 98.9% and 99.0%, respectively. GGO, consolidation and fibrous stripes were equally visible in STD and ULD in 100% (n=97), 36% (n=35) and 23% (n=22) of compatible viral pneumonia-CT patients, respectively. Air bronchogram sign detection was equivalent, concerning 23% (n=22) of patients in STD and 22% (n=21) in ULD. Crazy paving was visible in 24% (n=23) of patients in STD and only 8% (n=8) in ULD (P=0.003). Conclusions: In comparison to STD dose chest CT, ULD chest CT, with a mean reduction dose of 88.0%, has comparable diagnostic performance for detecting viral pneumonia on CT.

Mots clés: Multidetector computed tomography (multidetector CT); Coronavirus infections; Ultra-low-dose CT (ULD CT)

Domaines: Imagerie; Maladies infectieuses; Pneumologie et système respiratoire

Joël Greffier, Adel Hoballah, Alexandre Sadate, Fabien De Oliveira, Pierre-Geraud Claret, et al.. Ultra-low-dose chest CT performance for the detection of viral pneumonia patterns during the COVID-19 outbreak period: a monocentric experience. Quantitative Imaging in Medicine and Surgery, 2021, 11 (7), pp.3190-3199. ⟨10.21037/qims-20-1176⟩. ⟨hal-03632780⟩