Prognostic value of perfusion defect volume at dual energy CTA in patients with pulmonary embolism: Correlation with CTA obstruction scores, CT parameters of right ventricular dysfunction and adverse clinical outcome

Abstract Purpose To investigate the prognostic value of perfusion defect volume (PDvol) at dual-energy-CT-angiography (DE-CTA) in patients with acute pulmonary embolism (PE) by correlating PDvol with CTA-obstruction-scores (OS), CT parameters of right-ventricular-dysfunction (RVD), and adverse-clinical-outcome. Materials and methods DE-CTA of 60 patients (mean age: 65 ± 14.4 years) with PE were analyzed. Iodine maps were generated, and normalized PDvol – defined as volume of perfusion defects/total lung volume – was quantified. Furthermore, established prognostic parameters (Qanadli and Mastora-OS, and CT parameters of RVD) were obtained. CT parameters of RVD – namely the right ventricle/left ventricle (RV/LV) diameter ratio measured on transverse sections (RV/LVtrans), four-chamber views (RV/LV4ch), and RV/LV volume ratios (RV/LVvol) – were assessed. PDvol was correlated with OS, CT parameters of RVD and adverse clinical outcome (defined as the need for intensive care treatment or death). Results 10 of 60 patients with PE experienced adverse clinical outcome. Patients with adverse clinical outcome showed significantly higher PDvol (35 ± 11% vs. 23 ± 10%, p = 0.002), RV/LV ratios (RV/LV4ch 1.46 ± 0.32 vs. 1.18 ± 0.26, p = 0.005; RV/LVvol 2.25 ± 1.33 vs. 1.19 ± 0.56, p = 0.002) and higher Mastora global scores (52 vs. 13, p = 0.02) compared to those without adverse clinical outcome. A weak correlation was observed between PDvol and the Mastora global score ( r = 0.5; p = 0.0003), as well as between PDvol and RV/LV4Ch ( r = 0.432, p = 0.0006). No correlation was found between PDvol and the Qanadli score or the remainder of the RVD-CT parameters. Conclusion The extent of perfusion defects as assessed by DE-CTA correlates with adverse clinical outcome in patients with PE. Therefore, volumetric quantification of perfusion defects at DE-CTA allows the identification of low-risk patients who do not require intensified monitoring and treatment.