Comparison of Egg and Banana Sign, Carina Crossover Sign in Prediction of Pulmonary Embolism: A Cross-sectional Study

Abstract

Introduction: Acute pulmonary embolism is a life-threatening condition that can lead to sudden death. Pulmonary Artery Hypertension (PAH) can be found in the setting of acute pulmonary embolism. The Egg and Banana sign and Carina Crossover (CCO) sign are seen in PAH, which are present on Computed Tomographic scans (CT scans). Aim: To determine the accuracy of CT scans, the Egg and Banana sign, and CCO sign seen in PAH in the evaluation of pulmonary embolism. Materials and Methods: This retrospective, cross-sectional study was conducted from May 2019 to May 2021 in the Department of Radiodiagnosis at Father Muller Medical College Hospital in Mangalore, Karnataka, India. The CT scans of 102 consecutive patients who underwent CT Pulmonary Angiography (CTPA) for suspected pulmonary embolism were evaluated for the presence of the CCO sign and Egg and Banana sign. The CCO sign was considered positive when the right pulmonary artery (PA) was seen crossing anterior to the carina at its bifurcation. The Egg and Banana sign was considered present when the PA was found lateral to the aortic arch, with the PA described as the Egg and the arch as the Banana. The results were statistically analysed using Statistical Package for Social Sciences version 3.0. Results: Pulmonary embolism was seen in 26 out of 102 cases, with a mean age of 60.2±16.27 years. Pulmonary embolism was absent in 76 cases with a mean age of 55.8±17.11. An equal gender distribution was seen in 26 cases of pulmonary embolism. The Egg and Banana sign was found in 8 out of 26 patients with pulmonary embolism and had a specificity of 78.9%, negative predictive value of 76.92%, and diagnostic accuracy of 66%. The CCO sign was seen in 14 out of 26 cases of pulmonary embolism and had a higher specificity of 81.58% and diagnostic accuracy of 74.51%. The CCO sign had a statistically significant value in detecting pulmonary embolism. Conclusion: According to the study, the CCO sign had a higher accuracy in detecting pulmonary embolism compared to the Egg and Banana sign. The accuracy was further improved when combined with other signs of pulmonary embolism.