We investigated the usefulness of magnetic resonance imaging (MRI) with gadolinium-diethylene-triamine-pentaacetic acid (Gd-DTPA) in assessing myocardial damage from valvular aortic stenosis (AS). Cardiac catheterization and echocardiography were performed in 17 patients with AS. T1-weighted spin-echo sequence was used to obtain magnetic resonance images of short-axis planes of the left ventricle before and after intravenous Gd-DTPA injection in all patients using a 1.5 Tesla imager. Patients were divided into 2 groups according to the presence or absence of regional myocardial enhancement in the images. The Gd-DTPA-enhanced magnetic resonance images of 7 patients showed circumferential subendocardial enhancement. All patients with enhancement had a history of heart failure and were in New York Heart Association functional class III or IV, whereas patients without enhancement were in New York Heart Association functional class I or II. Patients with enhancement had a smaller aortic valve area (0.28 +/- 0.09 vs 0.38 +/- 0.07 cm2/m2, p <0.05), a higher transvalvular pressure gradient (109 +/- 40 vs 68 +/- 18 mm Hg, p <0.05), greater elevation of left ventricular end-diastolic pressure (22 +/- 11 vs 12 +/- 2 mm Hg, p <0.05), and greater reduction in left ventricular ejection fraction (40 +/- 9 vs 59 +/- 10%, p <0.05). Subendocardial enhancement by Gd-DTPA-enhanced MRI was thus shown to be closely related to the severity of AS. In conclusion, Gd-DTPA-enhanced MRI is a new noninvasive tool that can provide useful information about myocardial damage in AS.