Magnetic Resonance Imaging of Atrial Septal Defects

An atrial septal defect (ASD) is a hole in the heart that can lead to heart failure. Depending on the size and severity of the ASD, They can be treated during a heart catheterization with a special device that can permanently seal the ASD, but knowing the exact size and severity of the ASD is crucial. Newer MRI techniques may provide a better way at diagnosing the size and severity of an ASD. We compared MRI to other standard clinical ways for evaluating an ASD.

Background: Atrial septal defect (ASD) flow can be measured indirectly by velocity-encoded cardiovascular magnetic resonance (veCMR) of the pulmonary artery and aorta (Qp/Qs). Imaging the secundum ASD en face could potentially enable direct flow measurement and, additionally, provide valuable information regarding ASD size, shape, location, and proximity to other structures.

Methods: Patients referred for possible transcatheter ASD closure underwent a comprehensive standard evaluation including transesophageal and/or intracardiac echocardiography (ICE), and invasive oximetry. CMR was performed in parallel and included direct en face veCMR after an optimal double-oblique imaging plane was determined accounting for ASD flow direction and cardiac-cycle interatrial septal motion.

We hypothesized that En face veCMR using an optimized imaging plane can accurately determine ASD flow, size, and morphology, and that it would provide information incremental to comprehensive standard evaluation.

Inclusion Criteria:

• Suspected Atrial Septal Defect (ASD) undergoing evaluation for possible transcatheter closure

Exclusion Criteria:

• Contraindications to magnetic resonance imaging
• known sinus venosus or primum defects