Images in Cardiovascular Medicine
Four-Dimensional Flow Magnetic Resonance Imaging in the Evaluation of Intracardiac Oxygenation in an Infant With a Single Ventricle
2022 年 86 巻 1 号 p. 166-
詳細
2022 年 86 巻 1 号 p. 166-
A female infant with a double-outlet single ventricle was experiencing severe hypoxemia. At 8 months, catheterization showed a pulmonary-to-systemic flow (Qp/Qs) ratio of 1.6 and arterial oxygen saturation of 85%, 69% in the pulmonary artery and ascending aorta, respectively (Figure A). Echocardiography showed a 9.2-mm atrial septal defect (ASD) and bidirectional flow. Angiography of the superior vena cava demonstrated that venous blood was flowing into the anterior ascending aorta (Figure B). Due to the high Qp/Qs and wide ASD, the cause of cyanosis remained unclear. Four-dimensional flow magnetic resonance imaging (4D flow MRI) showed that the blood from each atrium was not mixing sufficiently in the single ventricle (Figure C). Additionally, the blood from the right atrium was flowing in a circular motion around the ASD, and the oxygenated blood in the left atrium was not sufficiently flowing into the right atrium (Figure D–F, Supplementary Movies 1–3). Based on these findings, the Glenn procedure was performed and her percutaneous oxygen saturation increased to 90%.
(A) Schema and arterial oxygen saturation at each site. (B) Venous angiogram. (C–F) Stream line of the heart (C), the right and left atria (D,E), in the ASD stream line (F). (E,F) Stream line at ① atrial relaxation phase, ② atrial filling phase, ③ atrial ejection phase, and ④ atrial contraction phase. Ao, aorta; ASD, atrial septal defect; LA, left atrium; PA, pulmonary artery; RA, right atrium; RV, right ventricle.
4D flow MRI can visualize the vortex rings of blood flow,1 and has been utilized in intracardiac shunts in congenital heart disease.2 In the present case, streams evaluated in 4D flow revealed insufficient mixing of oxygenated and deoxygenated blood, despite the presence of a large ASD. These findings were useful for the treatment strategy.
The authors declare they have no conflicts of interest.
Kagoshima University Ethics Committee, 190055.
Supplementary Movie 1. Stream line in the ASD (1).
Supplementary Movie 2. Stream line in the ASD (2).
Supplementary Movie 3. Stream line of the heart.
Please find supplementary file(s);
http://dx.doi.org/10.1253/circj.CJ-21-0551
