Pulmonary artery anatomy in congenital heart disease with decreased pulmonary blood flow by magnetic resonance imaging

Abstract

We performed magnetic resonance imaging (MRI) in 65 patients (ages 8 days to 17 years old) with congenital heart disease accompanied by pulmonary atresia or stenosis, who had not undergone radical or functional repair of the heart to assess the usefulness of MRI in evaluating the pulmonary artery (PA) tree and calculating the diameter of the pulmonary arteries. Imaging was performed with a superconducting magnet operating at 0.5 tesla with spin-echo sequence. MRI clearly visualized the pulmonary artery anatomy and the spatial relation between PA and great vessels in all 65 patients. In 11 of 12 patients with branch PA stenosis, MRI clearly demonstrated the sites of pulmonary stenosis. The diameter of the PAs and Nakata's PA index, as measured by MRI, were significantly correlated with those measured by PA angiography (y = 0.88X + 0.5, r = 0.97 for the right PA, y = 0.91X + 0.1, r = 0.96 for the left PA, and y = 0.74X + 33, r = 0.93 for the PA index). MRI technique in this study had low intra- and interobserver variations. In conclusion, MRI was a useful modality for noninvasive assessment of the PA in congenital heart disease with decreased pulmonary blood flow.