Abstract
BACKGROUND: This study aimed to explore the diagnostic accuracy of cardiac magnetic resonance tissue tracking (CMR-TT) technology in the quantitative evaluation of left myocardial infarction for differentiating between acute and chronic myocardial infarction. METHODS: A total of 104 human subjects were enrolled in this prospective study. Among them, 64 healthy subjects and 40 patients with left ventricular myocardial infarction and 7 days and 6 months' follow-up CMR studies, including steady-state free precession (SSFP) sequence and late gadolinium enhancement MR imaging, were enrolled. The strain parameters of the infarcted myocardium, its corresponding remote segments, and global right ventricular strain were analyzed using tissue tracking technology, and CMR-TT 3D strain parameters in radial, circumferential, and longitudinal directions were obtained. Receiver operating characteristic (ROC) analysis was used to determine the diagnostic accuracy of the CMR-TT strain parameters for discriminating between acute and chronic myocardial infarction. RESULTS: Peak radial strain (RS) of infarcted myocardium increased from 12.99±7.28 to 18.57±6.66 at 6 months (P<0.001), whereas peak circumferential strain (CS) increased from -8.82±4.71 to -12.78±3.55 (P<0.001). CS yielded the best areas under the ROC curve (AUC) of 0.751 in showing differentiation between acute and chronic myocardial infarction of all the strain parameters obtained. The highest significant differences between acute myocardial infarction and normal myocardium, both in the left and right ventricles, were also found in the RS (P<0.001) and CS (P<0.001). CONCLUSIONS: RS and CS obtained by CMR-TT have high sensitivity and specificity in the differential diagnosis of acute versus chronic myocardial infarction, and their use is thus worth popularizing in clinical application.