Assessment of central pulmonary arteries in patients with obstructive lesions of the right ventricle: comparison of MR imaging and cineangiography.

Abstract

MR imaging and cineangiography were compared in the evaluation of central pulmonary arteries in patients with obstructive lesions of the right ventricular outflow tract. Prospectively, we obtained multiplanar spin-echo cardiac-gated MR images and cineangiograms in 29 patients who had obstructive lesions of the right ventricular outflow tract (31 examinations). Blinded first observers evaluated the presence, size, confluence, and stenoses of the pulmonary artery and the presence of aortopulmonic collaterals. Blinded second observers evaluated the presence and size of the pulmonary artery. Each imaging technique revealed pulmonary arteries that were not shown by the other technique. We measured pulmonary arteries as being smaller on MR images; however, we found good correlation between the two techniques (r value for right pulmonary arteries = .82, r value for left pulmonary arteries = .88). MR imaging revealed five of six stenoses in the left pulmonary artery, but our observers falsely identified five right pulmonary arteries as stenotic from MR images. Interobserver variability and intraobserver variability in estimating size of the pulmonary artery on MR images and cineangiograms were similar and were less than variability when paired estimations in the same patient with both imaging techniques were compared. MR imaging and cineangiography should be viewed as complementary techniques.