Teenager underwent pulmonic valvulotomy for pulmonic stenosis. MR study was requested to evaluate the pulmonary circulation and pulmonic valve.

Figure 1: Gadolinium-enhanced 3D MR angiography of the pulmonary arteries shows residual enlargement of the main pulmonary artery and especially the left pulmonary artery.

Figure 2: Cine gradient echo imaging through the pulmonic valve demonstrates three leaflets widely separated throughout the cardiac cycle (same appearance in systole and diastole). Quantification of the degree of pulmonic insufficiency was then performed using phase-contrast cine gradient echo imaging.

Figure 3-A: Phase contrast cine gradient echo imaging during systole shows cephalad flow through both the ascending aorta and pulmonary artery.

Figure 3-B: Phase contrast cine gradient echo imaging during diastole shows cephalad flow through both the ascending aorta and pulmonary artery.

Figure 4: Phase contrast cine gradient echo imaging results after processing using commercially available software. Data are processed by drawing a large region of interest around the entire pulmonic valve area in Figure 2-3. The volume flow rates through the pulmonic valve over the cardiac cycle are plotted. Forward flow (above the baseline) equals 120 ml/heartbeat while reverse flow (below baseline) equals 50 ml/heartbeat for a regurgitant fraction of 0.42.

Pulmonic insufficiency (with quantification of regurgitant volume).

MR imaging can provide useful physiologic measurements in congenital and adult heart disease. Using segmented k-space or echo planar imaging methods for cine phase contrast imaging, flow quantification can be performed with acquisition times of 20 seconds or less.