Magnetic resonance imaging compared with angiography in the evaluation of intermediate-term result of coarctation balloon angioplasty.

Between July 1986 and December 1990, 24 consecutive adult patients with native coarctation of the aorta underwent balloon dilatation. Their ages ranged from 15 to 55 (mean 25) years. Dissection of the aorta developed in one patient. The remaining 23 patients were restudied by catheterization and magnetic resonance imaging (MRI) 8 to 60 (mean 21) months after dilatation. Both studies were performed between 1 and 180 (mean 40) days of each other. The diameter of the aorta at the site of previous coarctation was measured on angiogram and MRI by two independent observers. The data were compared by means of linear regression analysis. The gradient across the previous coarctation site ranged from 0 to 20 (mean 7 +/- 7.3) mm Hg. The diameter of the aorta at the site of previous coarctation measured on angiogram was 13.7 +/- 3.7 mm and on MRI it measured 13.5 +/- 3.7 mm, with excellent correlation (r = 0.96, SEE = 0.92, p < 0.001). Two patients had small aneurysms 2 cm in diameter demonstrated by angiography and MRI, and two patients developed restenosis, diagnosed correctly by both cardiac catheterization and MRI. This study demonstrates that MRI provides excellent visualization of the anatomy of the aorta and is a good noninvasive method for follow-up of patients undergoing balloon coarctation angioplasty.