Correlation of qanadli obstruction index (QOI) and atrial size on CT pulmonary angiography (CTPA) in patients with pulmonary thromboembolism

Abstract

Abstract Background Pulmonary thromboembolism (PTE) is a potentially fatal and life-threatening variation of venous thromboembolism (Faghihi Langroudi et al. in Radiol Res Pract 2:1–6, 2019). Computed Tomography Pulmonary Angiography (CTPA) has been proven to be an invaluable first-line diagnostic tool in the early identification of pulmonary thromboembolism (Aviram et al. J Thromb Haemost 9(2):293–299, 2011; Ghaye et al. in RadioGraphics. 26 1 23 39, 2006). Preliminary studies have suggested the correlation between atrial size and clot burden in the pulmonary arteries in patients with pulmonary thromboembolism (Faghihi Langroudi et al. in Radiol Res Pract 2:1–6, 2019; Aviram et al. J Thromb Haemost 9(2):293–299, 2011). Clot burden is calculated by applying the CTPA dependent score—Qanadli Obstruction Index (QOI)/Pulmonary Arterial Obstruction Index (PAOI) in the pulmonary arteries. Results There was a significant negative correlation between left atrial/right atrial area, left atrial/right atrial short axis and left atrial/right atrial long axis with the PAOI, especially the left atrial/right atrial area ratio and left atrial/right atrial short axis ratio, which showed the most significant negative correlation. Additionally, an LA/RA area of ≤ 0.60 correlated with a PAOI of > 20 and an obstruction percentage of > 50%, which can serve as a predictor of right ventricular dysfunction. Conclusions These atrial dimensions can serve as additional early parameters that reflect changes in the cardiac morphology in response to the clot load within the pulmonary arteries, and can thus contribute towards a more comprehensive risk assessment in patients with acute pulmonary thrombo-embolism.