Magnetic Resonance Angiography of a Pulmonary Artery Stenosis Late After Cardiac Surgery
A19-year-old man with known dextrocardia, situs inversus, and complete surgical correction of a double-outlet right ventricle was seen in the outpatient clinic for follow-up after total correction, including the implantation of a pulmonary homograft. During echocardiography, a dilated right atrium and right ventricle were noted. Increased right ventricular pressure (50 mm Hg; tricuspid regurgitation, 3.5 m/s) could only partially be explained by pulmonary valve stenosis. The pulmonary artery branches could not be visualized echocardiographically. Magnetic resonance angiography was performed using the breath-hold contrast-enhanced 3D gradient echo sequence described by Prince et al.1 The imaging time was 24 seconds and the resolution was 1.0×2.6×1.3 mm. After the acquisition, the datasets were transferred to a dedicated graphic workstation (Indigo2, Silicon Graphics) for 3D evaluation with a volume-rendering technique2 3 using commercially available software (VoxelView, Vital Images). Three-dimensional representation with volume rendering showed the situs inversus very clearly (Figure 1⇓). The pulmonary homograft is located on the right side of the patient, with the ascending aorta on the left and descending aorta to the right of the spine. The branch vessels are reversed, with a left brachiocephalic artery as the first arch branch.
To visualize the pulmonary artery branches, the heart and aorta were subtracted from the source images (Figure 2⇓). Both the pulmonary arteries and veins are filled with contrast. The right pulmonary artery showed an important stenosis at the anastomosis from the pulmonary homograft. Figure 3⇓ is a detailed view of the origin of the right pulmonary artery.
The diagnosis was confirmed during reoperation, which consisted of implanting a new pulmonary homograft and reconstructing the right pulmonary artery.
A movie version of Figure 2⇓ (showing 3D rotation) can be found at www.circulationaha.org
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to the Circulation Editorial Office, St Luke’s Episcopal Hospital/Texas Heart Institute, 6720 Bertner Ave, MC1–267, Houston, TX 77030.
- Copyright © 2000 by American Heart Association