Purpose:
Acute pulmonary embolism (APE) is a potentially life-threatening condition requiring rapid risk stratification. Although computed tomography (CT) pulmonary angiography is the diagnostic gold standard, the prognostic value of CT-derived radiological markers remains incompletely defined.

Material and methods:
This retrospective study included 91 patients with APE. CT-derived radiological parameters – including the Qanadli obstruction index (QI), Mastora score, right ventricle/left ventricle (RV/LV) ratio, and RV wall thickness – were evaluated together with clinical severity scores (Pulmonary Embolism Severity Index [PESI], and its simplified version [sPESI]) and laboratory markers. Associations with disease severity and intensive care unit (ICU) admission were assessed using correlation and receiver operating characteristic (ROC) analyses.

Results:
Among the patients, 52.7% were female and 27.5% required ICU admission. PESI, sPESI, QI, Mastora score, and RV/LV ratio were significantly higher in ICU-admitted patients (all p < 0.01). QI correlated significantly with PESI (r = 0.433), disease severity (r = 0.565), D-dimer (r = 0.510), and troponin levels (r = 0.536) (all p < 0.001). The Mastora score showed similar significant associations with clinical severity indices, RV/LV ratio, and laboratory markers. ROC analysis demonstrated that PESI had the highest predictive accuracy for ICU admission (area under the curve, AUC = 0.849), followed by RV/LV ratio (AUC = 0.838), sPESI (AUC = 0.791), and both QI and Mastora score (AUC = 0.782). Platelet-to-lymphocyte ratio, systemic immune-inflammation index, and RV wall thickness were not significant predictors.

Conclusions:
CT-derived obstruction indices and RV/LV ratio provide clinically meaningful prognostic information for ICU requirement in APE, particularly when integrated with established clinical severity scores.