[Left ventricular trabeculae evaluated with MRI in dilated cardiomyopathy and old myocardial infarction]

The morphological examination of the left ventricular trabeculae was performed using MRI (0.5T) in 14 normal volunteers, 12 patients with dilated cardiomyopathy (DCM), and 9 patients with old myocardial infarction (OMI). Left ventricular trabeculae were observed at the free walls of the left ventricle in all subjects, but not at the septal wall. Left ventricular trabeculae were larger in DCM than in the normals. The trabeculae were scarce in OMI and inner sides of the infarcted myocardium were very smooth. The development of the left ventricular trabeculae was graded as diminished, ordinary, and marked. Ordinary trabeculae were seen in 86% of the normals, whereas; marked trabeculae in 75% of DCM, and diminished trabeculae in 78% of OMI. In patients with DCM, the mean area of the left ventricle with marked trabeculae was greater than that with ordinary trabeculae. The more dilated left ventricle, the thinner the anterior wall was and the lower the ejection fraction was in DCM and OMI, though there were no significant differences in values of these 3 items between DCM and OMI. The MRI findings on the development of the trabeculae were confirmed in patients with DCM at autopsy. Thus, the MRI findings were very useful in the differential diagnosis between DCM and OMI.