The Comparison of the Diagnostic Value of Left Atrial Pulmonary Vein Single-Phase and Dual-Phase Enhanced CT Scanning for Left Atrial Appendage Thrombosis and SEC in Patients with Atrial Fibrillation

OBJECTIVE: The accuracy of left atrial pulmonary vein CT enhanced single-phase and dual-phase scanning in the detection of left atrial appendage (LAA) thrombosis and spontaneous echo contrast (SEC) before radio frequency ablation was compared in atrial fibrillation patients, so as to optimize the scanning scheme. METHODS: 78 patients with atrial fibrillation who were admitted to Cangzhou Central Hospital from October 2020 to September 2021 and underwent bilateral enhanced CT scan of left atrial pulmonary vein and transesophageal echocardiography (TEE) examination for planned frequency ablation were selected. TEE results were used as the “gold standard” to compare the diagnostic efficacy of the first phase, second phase, and double-phase comprehensive mode of enhanced left atrial pulmonary vein CT in detecting left atrial thrombosis and SEC. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value were 88.9%, 84.1%, 42.1%, and 98.3%, respectively, in the detection of left atrial thrombosis and SEC by the first phase of CT enhanced scan. The sensitivity, specificity, positive predictive value, and negative predictive value were 22.2%, 98.6%, 66.6%, and 90.7%, respectively, in the detection of left atrial thrombosis and SEC by the second phase of CT enhanced scan. The sensitivity, specificity, positive predictive value, and negative predictive value were 88.9%, 84.1%, 42.1%, and 98.3%, respectively, in the detection of left atrial thrombosis and SEC by the double-phase comprehensive mode of CT enhanced scan. There was no statistically significant difference in the accuracy of CT diagnosis of left atrial appendage thrombosis and SEC between the three modes of the first phase, the second phase, and the double-phase comprehensive CT (P > 0.05). The mean effective radiation dose of double-phase enhanced scan was 7.49 ± 1.02 mSv. CONCLUSION: Single-phase enhanced CT scan of left atrial pulmonary vein can meet clinical requirements and significantly reduce the radiation dose compared with double-phase enhanced CT scan. Therefore, it is recommended as an initial screening examination for patients with atrial fibrillation before radiofrequency ablation.