TY - JOUR T1 - Evaluation of acute pulmonary embolism by sixty-four slice multidetector CT angiography: Correlation between obstruction index, right ventricular dysfunction and clinical presentation JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2015.PA3746 VL - 46 IS - suppl 59 SP - PA3746 AU - Noha Attia AU - Gehan Seifeldein AU - Ali Hasan AU - Abdelkarim Hasan Y1 - 2015/09/01 UR - http://erj.ersjournals.com/content/46/suppl_59/PA3746.abstract N2 - Background: The severity of acute pulmonary embolism (PE) as estimated by the clot burden, obstruction index (OI) as well as right ventricular dysfunction (RVD) can be evaluated using multidetector CT (MDCT) pulmonary angiography.Objective: To investigate the correlation between the MDCT OI, RVD and clinical status in patients with acute PE.Methods: Seventy patients proved to have PE using 64-slice MDCT underwent full medical history and clinical examination. The clot burden in the pulmonary vascular tree was quantified using the established and validated Qanadli score and the OI which is a scoring system based on the site of obstruction and the degree of pulmonary arteries occlusion was calculated. RVD was evaluated using MDCT and was considered present if the RV/LV diameter using the four-chamber view of the heart > 1 and pulmonary artery diameter > 2.9mm. The best cut-off for the OI to detect the presence of RVD was constructed using ROC curve.Results: The mean OI was 35% ± 16%. It was significantly higher in patients with dyspnea, tachypnea and hypotension. The mean OI was also significantly higher in patients with RVD (P <0.001). A positive correlation was found between the OI and both the CT pulmonary artery diameter (r=0.661, P<0.001) and the RV/LV diameter ratio (r=0.628, P<0.001). A CT OI >43% identified more than 90% of patients with RVD (area under the curve on ROC analysis: 0.825; p <0.001).Conclusion: The mean OI correlated linearly with RVD and an OI >43% proved to be an independent predictor of worse clinical status and RVD in patients with acute PE. ER -