Interatrial Shunt Detected in Coronary Computed Tomography Angiography: Differential Features of a Patent Foramen Ovale and an Atrial Septal Defect

Objective: To determine differential findings of patent foramen ovales (PFOs) and atrial septal defects (ASDs) demonstrating interatrial shunting on coronary computed tomography (CT) angiography Methods: We retrospectively analyzed 15 cases of patients demonstrating a contrast jet from the left to the right atrium on CT and interatrial shunting oil echocardiography. According to the echocardiography results, patients were divided into PFO (n = 10) or ASD (n = 5) groups. The contrast jet direction and atrial septum appearance on CT were compared between the 2 groups. Results: The PFO group had a contrast jet flowing toward the inferior vena cava, and the atrial septum appeared channel-like. The ASD group had a contrast jet flowing perpendicular to the atrial septum ill all but one of the patients, and the atrial septum appeared as a membrane with a hole. Conclusions: Atrial septal defects and PFOs can be differentiated using the characteristic direction of the contrast jet from the left to right atrium and the appearance of the atrial septum on coronary CT angiography.