Myocardial Viability: Comparison of Free-Breathing Navigator-echo-gated Three-Dimensional Inversion-Recovery Gradient-Echo MR and Standard Multiple Breath-Hold Two-Dimensional Inversion-Recovery Gradient-Echo MR

Abstract

Purpose: To compare a free-breathing, navigator-echo-gated, three-dimensional, inversion-recovery, gradientecho, MR pulse sequence (3D-MRI) with standard, multiple breath-hold, two-dimensional, inversion-recovery, gradient-echo MR (2D-MRI) for the evaluation of delayed hyperenhancement of nonviable myocardium in patients with chronic ischemic heart disease. Materials and Methods: Ten patients with chronic ischemic heart disease were enrolled in this study. MRI was performed on a 1.5-T system. 3D-MRI was obtained in the short axis plane at 10 minutes after the administration of Gd-DTPA (0.2 mmol/kg, 4 cc/sec). Prospective gating of the acquisition based on the navigator echo was applied. 2D-MRI was performed immediately after finishing 3D-MRI. The area of total and hyperenhanced myocardium measured on both image sets was compared with paired Student t-test and Bland-Altman method. By using a 60-segment model, the transmural extent and segmental width of the hyperenhanced area were recorded by 3-scale grading method. The agreement between the two sequences was evaluated with kappa statistics. We also evaluated the agreement of hyperenhancement among the three portions (apical, middle and basal portion) of the left ventricle with kappa statistics. Results: The two sequences showed good agreement for the measured area of total and hyperenhanced myocardium on paired t-test (p=0.11 and p=0.34, respectively). No systematic bias was shown on Bland-Altman analysis. Good agreement was found for the segmental width (ĸ=0.674) and transmural extent (ĸ=0.615) of hyperenhancement on the segmented analysis. However, the agreement of the transmural extent of hyperenhancement in the apical segments was relatively poor compared with that in the middle or basal portions. Conclusion: This study showed good agreement between 3D-MRI and 2D-MRI in evaluation of non-viable myocardium. Therefore, 3D-MRI may be useful in the assessment of myocardial viability in patients with dyspnea and children because it allows free-breathing during the examination.