Analysis of first-pass and delayed contrast-enhancement patterns of dysfunctional myocardium on MR imaging: Use in the prediction of myocardial viability

OBJECTIVE. The purpose of the study was to analyze first-pass and delayed c ontrast-enhancement patterns of dysfunctional myocardial regions on MR imag ing after injection of gadopentetate dimeglumine to predict myocardial viab ility in patients with coronary artery disease. SUBJECTS AND METHODS. Twelve patients with wall motion abnormalities and re lated coronary artery disease revealed by conventional coronary angiography underwent MR imaging at 1.5-T before and 3 months after revascularization therapy. Short-axis images were acquired using a cine gradient-echo sequenc e. Each slice was divided into eight segments. Overall, 73 segments with im paired contractility were imaged during the first-pass and 14 +/- 2 min aft er injection of 0.05-mmol/kg gadopentetate dimeglumine at a flow of 3 ml/se c using a T1-weighted turbo fast low-angle shot sequence. Improved systolic wall thickening 3 months after revascularization served as the criterion o f viability. RESULTS. At study entry, 26 dysfunctional segments showed delayed hyperenha ncement compared with the adjacent functional segments within the same slic e, and 47 did not reveal hyperenhancement, After revascularization, 25 (96% ) of the 26 hyperenhanced segments did not recover function, whereas 39 (83 %) of the 47 segments without hyperenhancement showed mechanical improvemen t, Segment-related sensitivity and specificity for the correlation of lack of delayed hyperenhancement with myocardial viability were 39 (98%) of 40 a nd 25 (76%) of 33, respectively. Hypoenhancement during first-pass did not serve as a reliable criterion of viability. CONCLUSION. Evidence of delayed hyperenhancement of dysfunctional myocardiu m may be used to predict lack of mechanical improvement or nonviability, wh ereas the lack of hyperenhancement can be correlated with improvement of re gional contractility or viability after revascularization.