Magnetic resonance phase-shift velocity mapping in pediatric patients withpulmonary venous obstruction

Objectives This study evaluated the accuracy, advantages and clinical effic acy of magnetic resonance (MR) phase-shift velocity mapping, in delineating the site and the hemodynamic severity of pulmonary venous (PV) obstruction in patients with congenital heart disease (CMD). Background Magnetic resonance phase-shift velocitt mapping of normal pulmon ary veins and of obstructed PV pathways have been previously reported in a mainly adult population. Methods The study population (33 pts) underwent MR phase-shift velocity map ping of their PV pathways. These results were compared with cardiac cathete rization and Doppler echocardiography data. Results The study population (0.4 to 19.5 years) consisted of a study group (PV pathway obstruction, n = 7) and a control group (no PV obstruction, n = 26). No patients had any left-to-right shunt lesions. The MR imaging disp layed precise anatomical detail of the pulmonary veins. Phase velocities in the control group ranged from 20 to 71 cm/s, whereas velocities in the stu dy group ranged from 100 to 250 cm/s (p = 0.002). The MR phase velocities ( 154 +/- 0.53 cm/s) compared favorably with Doppler echocardiography (147 +/ - 0.54 cm/s), (r = 0.76; p = 0.05). The MR velocity mapping was 100% specif ic and 100% sensitive in detecting PV obstruction, although the absolute gr adient measurements among MR phase mapping, echocardiographic Doppler and c atheterization did not show statistically significant correlation. Conclusions In the absence of any associated left-to-right shunt lesions, P V velocities of 100 cm/s and greater indicated significant obstruction. The MR phase-shift velocity mapping, together with MR spin echocardiography an d MR angiography provides comprehensive anatomic and physiologic data that may obviate the need for further invasive studies. (J Am Coll Cardiol 2001; 38:262-7) (C) 2001 by the American College of Cardiology.