Validity of the Ratio of Pulmonary Artery Diameter to Aortic Diameter in the Diagnosis of Pulmonary Embolism in the Emergency Department

Abstract

Background: Pulmonary thromboembolism can be easily diagnosed with computed tomography (CT) and pulmonary angiography (CTPA). However, diagnosis is difficult since a contrast agent cannot be used. Several criteria are recommended for the diagnosis of pulmonary embolism (PE) with non-enhanced CT. Objectives: The aim of this study is to investigate the value of the increase in the pulmonary artery diameter (PA-D) and the ratio of the pulmonary artery diameter / ascending aorta diameter (Ao-D) ratio (PA-D/Ao-D) in the diagnosis of PE in the emergency department (ED). Methods: The CTPA of patients diagnosed with PE (n=88) and a control group (n=89) were examined retrospectively. The main PA (MPA), right MPA (RMPA), left MPA (LMPA), and Ao-D were measured. The ratio of PA-D and Ao-D was calculated. Results: Mean age of participants of this study was 67.85±17.03 (Min:18, Max:98) in the PE group and 67.31±20.17 (Min:20, Max:91) in the control group (P=0.272). The PE diagnosis of RMPA, right segmental PA, and right subsegmental PA were found to be more than the left side. Moreover, the mean D-Dimer levels were found to be higher in the PE group (7.31±3.528 mcg/L), compared to the control group (1.52±1.042 mcg/L) (P=0.000). In the PE group, the mean Ao-D (35.14±4.55 mm) was larger, compared to the control group (34.97±5.28 mm); however, it was not statistically significant (P=0,828). In the PE group, the average MPA diameter (MPA-D) (30.45±4.77 mm) was larger than that of the control group (28.35±3.81 mm) and statistically significant (P=0,001). In addition, in the PE group, the average MPA-D/Ao-D ratio (0.87±0.15) was higher in comparison to the control group (0.82±0.13) (P=0,016). Conclusion: The increase in PA-D and PA-D/Ao-D ratio can be used in the diagnosis of PE when contrast agent cannot be given on CT or when thrombus cannot be seen on CT for the diagnosis of PE in the ED.