ECG-Gated Cardiac CT Angiography Using 64-MDCT for Detection of Patent Foramen Ovale

Abstract

The purpose of our study was to show the feasibility of ECG-gated, 64-MDCT cardiac angiography for the detection of patent foramen ovale (PFO). Chart review was performed on 214 consecutive patients referred for clinically indicated 64-MDCT angiography. The study cohort consisted of 20 patients who had previously undergone transesophageal echocardiography (TEE). Blinded consensus review of each CT angiography was performed by two experienced cardiac radiologists and results were compared with TEE, which served as a reference standard. CT criteria for the diagnosis of PFO were distinct left atrial "flap" in the expected location of the septum primum, continuous column of contrast material connecting this flap to the right atrium, and a "jet" of contrast material from the column into the right atrium. Of the 20 patients who underwent both TEE and cardiac CT angiography, six (30%) were found to have a PFO by TEE. Using the presence of a left atrial flap as the only diagnostic criterion, all six cases of PFO were detected using CT (sensitivity = 100%). Of the 14 patients with no PFO seen on TEE, 12 of these were correctly identified using CT (specificity = 86%). Using all three criteria together, the sensitivity decreased to 66% and the specificity increased to 100%. ECG-gated cardiac CT angiography performed with a 64-MDCT scanner can be used to reliably detect PFO.