Quantitative Volumetric Analysis of the Patent Foramen Ovale Tunnel in Coronary Computed Tomography Angiography: Clinical Implications and Diagnostic Significance.

[OBJECTIVES] (a) To investigate the relationship between tunnel volume (TV) and morphologic parameters of interatrial septum (IAS) in cases with type 3 and type 4 IAS; (b) To investigate the relationship between TV of the IAS and ischemic gliotic foci in brain MRI.

[MATERIALS AND METHODS] We retrospectively reviewed the images of 301 cases who underwent CCTA in our center between 2020 and 2022. TV, tunnel length (TL), opening diameter of the right (ODRAE) and left atrium entrance (ODLAE), interatrial groove (IAG) diameter, and free flap length (FFL) were measured. The presence, number, and distribution of ischemic gliotic foci were examined in patients who had undergone brain MRI in the last 5 years before the CCTA. Pearson χ 2 , the Fisher Exact, Mann-Whitney U , linear regression analysis, Kruskal-Wallis test, and the Spearman correlation tests were used for statistical analysis of the data.

[RESULTS] A shorter FFL was related to the higher IAS type and increased likelihood of jet flow ( P =0.013). The correlation between wide IAG diameter and FFL was statistically significant ( P =0.003, r =0.22). The correlation between TV and ODRAE and ODLAE was also statistically significant (P <0.001, r =0.364, P <0.001, r =0.332, respectively). In type 3 and type 4 IAS, TV was associated with an increased number of ischemic gliotic foci ( P =0.008) and bilateral distribution ( P =0.006) on brain MRI.

[CONCLUSION] Measurement of TL, ODRAE, ODLAE, and tunnel diameter in symptomatic cases with type 3 and type 4 IAS is crucial in determining the appropriate treatment approach. By adding the TV to the defined parameters, we thought that this innovation would contribute to invasive and noninvasive treatment management.