Acute Pulmonary Embolism: Retrospective Cohort Study of the Predictive Value of Perfusion Defect Volume Measured With Dual-Energy CT

OBJECTIVE. The purposes of this study were to investigate dual-energy CT findings predictive of clinical outcome and to determine the incremental risk stratification benefit of dual-energy CT findings compared with CT ventricular diameter ratio in patients with acute pulmonary embolism. MATERIALS AND METHODS. A retrospective evaluation was conducted of the cases of 172 patients with acute pulmonary embolism who underwent dual-energy CT. Ventricular diameter ratio and relative perfusion defect volume were measured. The primary end-points were death within 30 days and pulmonary embolism-related death. RESULTS. A ventricular diameter ratio of 1 or greater was associated with increased risk of death within 30 days (hazard ratio, 3.822; p = 0.002) and pulmonary embolism-related death (hazard ratio, 18.051; p < 0.001). Relative perfusion defect volume was also associated with increased risk of death of any cause within 30 days (hazard ratio, 1.044; p = 0.014) and pulmonary embolism-related death (hazard ratio, 1.046; p = 0.017). However, the addition of relative perfusion defect volume to ventricular diameter ratio had no added benefit for prediction of death of any cause within 30 days (concordance statistic, 0.833 vs 0.815; p = 0.187) or pulmonary embolism-related death (concordance statistic, 0.873 vs 0.874; p = 0.866). CONCLUSION. Compared with ventricular diameter ratio alone, lung perfusion defect volume had no statistically significant added benefit for prediction of death of any cause within 30 days or of pulmonary embolism-related death among patients with acute PE.