Lisette van Dam

Chapter 12 182 Aims of the study We aimed to determine the clinical and CT parameters of patients with COVID-19 associated PE, i.e. the reasons for clinical suspicion of PE, the location of the pulmonary emboli in the pulmonary artery tree in general and in relation to COVID-19 affected pulmonary segments, total thrombus load, right to left ventricular diameter ratio (RV/LV ratio) and pulmonary artery trunk diameter. We compared the CT characteristics of acute PE in COVID-19 patients to those assessed in the control cohort. Image acquisition and analysis CTPA examinations were performed on a 320-multislice detector row CT scanner (Canon) after iodinated contrast administration. RV/LV ratio, pulmonary artery trunk diameter and total thrombus load for both COVID-19 cases and controls were evaluated by an expert thoracic radiologist (LK) with over 20 years of experience in CTPA reading. The maximum diameters of both the RV and LV were measured in the standard axial view in which the maximal distance between the ventricular endocardium and the interventricular septum perpendicular to the long axis of the heart were assessed. The pulmonary artery trunk was measured at its largest transverse diameter. The thrombus load was assessed by using the Qanadli CT pulmonary artery obstruction index, including 10 lung segments for each lung. 19 For each PE location, ground glass opacities or consolidations were reported as being present or not present for each affected lung segment. Also, the extent of COVID-19 lung lesions by ground-glass opacities and consolidations was visually assessed as percentage of affected lung volume. Clinical and CT characteristics of PE are described as mean with standard deviation (SD) or median with interquartile range (IQR). We calculated absolute differences in these characteristics between COVID-19 patients and controls with corresponding 95% confidence interval (95%CI). All statistical analyses were performed in SPSS version 25 (IBM, Armonk, NY, USA).