Evaluation of acute pulmonary embolism by sixty-four slice multidetector CT angiography: Correlation between obstruction index, right ventricular dysfunction and clinical presentation

Abstract

Introduction: MDCT pulmonary angiography is the method of choice for the detection of pulmonary embolism (PE). The severity of PE as estimated by the obstruction index (OI) and right ventricular dysfunction (RVD) can be evaluated with MDCT. Objective: To investigate the correlation between the OI, RVD and clinical presentation in patients with acute PE. Methods: Among 70 patients with suspected PE, 35 patients proved to have PE with MDCT. The CT OI and the RV/LV diameter (RVD-ratio) using the four-chamber view of the heart were calculated for PE patients. The cut-off for the OI to detect RVD was constructed using ROC curve. Results: Dyspnea and RVD (RVD-ratio >1) were significantly more common in patients with central pulmonary emboli. The mean OI (35% ± 19%) was significantly higher in patients with dyspnea, tachycardia and obesity. A positive correlation was found between the OI and both the CT pulmonary artery diameter (r = 0.66, p < 0.001) and the RVD-ratio (r = 0.628, p < 0.001). The mean OI was significantly higher in patients with RVD (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 PA diameter and RVD-ratio. OI > 43% proved to be an independent predictor of RVD.

Correlation of the Wells and Simplified Revised Geneva Scores with CT Pulmonary Artery Obstruction Index in Pulmonary Embolism

“…The results of the current investigation are consistent with those of the study conducted by Attia et al, which reported that the PAOI is correlated with dyspnea and tachycardia; however, they did not show any relationship with hemoptysis and chest pain, which are common in peripheral pulmonary embolisms (21). According to our results, Wells score can be used to evaluate the severity of PE similar to CT index.…”

Diagnostic implications of computed tomography pulmonary angiography in patients with pulmonary embolism

“…[ 26 ] There are several scoring systems reported to evaluate the pulmonary vascular tree and assessment of clot burden score. [ 16 ] The present study quantified clot burden scoring according to QS as it is more objective, easy to calculate, distinguish between partial and complete obstruction, and has less interobserver variability. [ 13 19 ] Serial imaging studies could be used to assess the degree of vascular obstruction which helps a clinician determine real-time risk stratification and monitoring of treatment in an objective way.…”

“…Similar to our findings, Attia et al . [ 16 ] reported a significant association between obesity and higher mean obstructive index in patients with acute PE. In our study, patients with right heart dilatation (RV/LV ratio >1.2) were more likely to have larger clot volume as compared to those without RV dilatation.…”

“…Our findings coincide with earlier studies which also observed a good correlation between RV dysfunction parameters (RV/LV ratio and PA diameter) and the severity of obstruction. [ 16 22 ]…”

“…[ 13 14 ] There are few clinical studies from the Middle East to evaluate the role of CTPA for diagnosis and prognosis of PE. [ 14 15 16 ] The aim of this study is to assess the diagnostic implications of different CT parameters, and to correlate the clot burden, cardiovascular measurements, and clinical presentation of patients with acute PE.…”