Direct En Face Imaging of Secundum Atrial Septal Defects by Velocity-Encoded Cardiovascular Magnetic Resonance in Patients Evaluated for Possible Transcatheter Closure

Abstract

Background-Atrial septal defect (ASD) flow can be measured indirectly by velocity-encoded cardiovascular magnetic resonance (veCMR) of the pulmonary artery and aorta. Imaging the secundum ASD en face could potentially enable direct flow measurement and provide valuable information about ASD size, shape, location, and proximity to other structures. Methods and Results-Forty-four patients referred for possible transcatheter ASD closure underwent a comprehensive standard evaluation, including transesophageal and/or intracardiac echocardiography and invasive oximetry. CMR was performed in parallel and included direct en face veCMR after an optimal double-oblique imaging plane was determined that accounted for ASD flow direction and cardiac-cycle interatrial septal motion. ASD flow measured by direct en face veCMR correlated better with invasive oximetry than indirect (pulmonary artery and aorta) veCMR (rϭ0.80 versus rϭ0.66). Additionally, 95% limits of agreement were narrower (Ϯ3.9 versus Ϯ5.1 L/min). En face veCMR determined that defects usually were eccentrically shaped (major/minor axis length Ͼ1.5) rather than circular, with 16% having extreme eccentricity (major/minor Ͼ2.0). Overall, ASD size by both veCMR and intracardiac echocardiography correlated with final device size; however, in small to medium defects (Ͻ3 cm 2 ) and extremely eccentric defects, veCMR correlated better with final device size than did intracardiac echocardiography. Importantly, CMR identified additional information in 9 patients (20%) that altered clinical management. Specifically, en face veCMR detected additional defects (nϭ3), large ASD with insufficient rim tissue (nϭ2), and sinus venosus defect with anomalous pulmonary vein (nϭ1). Cine and/or morphological imaging detected interrupted inferior vena cava (nϭ2) and sinus of Valsalva aneurysm (nϭ1). Conclusions-En

Time‐resolved spin‐labeled balanced steady‐state free precession cineangiography for visualizing intracardiac shunt: technical considerations and clinical feasibility

“…Through‐plane ASD flow, in the en face view, was successfully visualized as described previously (8–10). Figure 8 shows the en face view of a large ASD with white cross hairs defining its size and cross‐sectional shape.…”

“…SLC has potential application in the preprocedure assessment of ASD for closure device sizing and for excluding improper candidates. A previous study has shown that en face PC is superior to intracardiac echocardiography for device sizing and that CMR identifies those with anatomy unsuitable for percutaneous closure (10). Because PC has the disadvantage that a high velocity encoding setting may suppress the edges of a low velocity jet leading to underestimation of orifice size, SLC may theoretically provide a better estimation of ASD size as it is not susceptible to this potential error.…”

Assessment of atrial septal defects in adults comparing cardiovascular magnetic resonance with transoesophageal echocardiography

“…Velocity encoded contrast cine imaging was not performed in this study, however, this is another CMR technique that can provide information about the size and shape of the atrial septal defect [16,18] as well as provide accurate assessment of shunt magnitude from measuring flow in the systemic and pulmonary circulations [20,21]. However, this technique has not been used for the assessment of margins due to its limited spatial resolution.…”

2014 Korean Guidelines for Appropriate Utilization of Cardiovascular Magnetic Resonance Imaging: A Joint Report of the Korean Society of Cardiology and the Korean Society of Radiology

“…Evaluation of pulmonary veins prior to radiofrequency ablation for atrial fibrillation/left atrial and pulmonary venous anatomy including dimensions of veins for mapping purposes (Level of evidence: B, Appropriateness criteria: A) 246) reported that CMR provided information incremental to comprehensive standard evaluation that altered clinical management in 20% of patients. Recently, the catheter-based percutaneous aortic valve replacement has been introduced and the number of this procedure being performed has increased markedly.…”