Gated magnetic resonance imaging (MRI) provides excellent anatomic evaluation of the heart, but its capability for assessing cardiac physiology is less clear. Accordingly, regional left ventricular (LV) wall thickening was evaluated by multiphasic transverse images in 37 patients with a variety of myocardial diseases and in 9 normal subjects. Angiography and 2-dimensional echocardiography (2-D echo) were used for comparison. End-diastolic and end-systolic wall thickness, absolute systolic wall thickening and percent systolic wall thickening were determined in 7 regions. Mean systolic wall thickening in normal subjects was not significantly different among the regions. However, there was considerable individual variation in wall thickening, ranging from 18 to 100%. Patients with LV hypertrophy (n = 4), amyloid cardiomyopathy (n = 1), constrictive pericarditis (n = 5), and hypertrophic cardiomyopathy (n = 3) had absolute and percent systolic wall thickening within normal limits. Infarcted segments in patients with ischemic heart disease (n = 17) had reduced absolute and percent systolic wall thickening, often combined with diastolic wall thinning, whereas mean percent systolic wall thickening in adjacent normal myocardial regions was higher than in normal volunteers (p less than 0.001). In patients with coronary artery disease, MRI had a sensitivity and specificity of 93% in detecting regional wall motion abnormalities. Because sagittal images were not acquired, inferior wall motion abnormalities were not assessed by MRI due to parallel wall sectioning in transverse images.(ABSTRACT TRUNCATED AT 250 WORDS)