[Gadolinium-diethylenetriamine pentaacetic acid enhanced magnetic resonance imaging of dilated cardiomyopathy: clinical significance of abnormally high signal intensity of left ventricular myocardium].

This study investigated the clinical significance of abnormally high signal intensity in the left ventricular myocardium on gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance (MR) imaging in patients with dilated cardiomyopathy. Gd-DTPA enhanced MR imaging, Tl-201 myocardial single photon emission computed tomography (SPECT), Tc-99m radionuclide angiocardiography, M-mode echocardiography, electrocardiography and chest radiography were performed in 18 patients with dilated cardiomyopathy. The left ventricle was divided into five areas, the anteroseptal, anterolateral, inferoseptal, posterolateral and apical areas. Five patients (group A) had 0-2 and 13 patients (group B) had 3-5 high signal intensity areas. High signal intensity areas were demonstrated in 19 of 90 areas (21%) before Gd-DTPA enhancement and 50 of 90 areas (56%) after enhancement. Fifteen of 34 areas (44%) with abnormal Tl-201 uptake showed high signal intensity before Gd-DTPA enhancement and 31 (91%) showed high signal intensity after enhancement. Fifteen areas without abnormal Tl-201 uptake also showed high signal intensity after enhancement. Left ventricular ejection fraction (LVEF) and percent fractional shortening (%FS) in group B were lower than those in group A. LVEF(r = 0.78) and %FS (r = 0.82) were significantly correlated with the number of high signal intensity areas. Systolic left ventricular dimension was larger in group B than that in group A, and a significant correlation (r = 0.62) between systolic left ventricular dimension and the number of high signal intensity areas was found. There was no significant difference in right ventricular ejection fraction, left ventricular peak filling rate, diastolic left ventricular dimension, left ventricular thickness, cardiothoracic ratio or SV1+RV5 or 6 between group A and B. There was no correlation of peak filling rate, diastolic left ventricular dimension, cardiothoracic ratio or SV1+RV5 or 6 with the number of high signal intensity areas. These results suggest that abnormal high signal intensity on Gd-DTPA enhanced MR imaging may reflect myocardial degeneration, necrosis or fibrosis, and the high signal intensity predicts the severity of left ventricular dysfunction in dilated cardiomyopathy.