Comparison between Three-Dimensional Navigator-Gated Whole-Heart MRI and Two-Dimensional Cine MRI in Quantifying Ventricular Volumes.

OBJECTIVE

To test whether the method utilizing three-dimensional (3D) whole-heart MRI has an additional benefit over that utilizing conventional two-dimensional (2D) cine MRI in quantifying ventricular volumes.

MATERIALS AND METHODS

In 110 patients with congenital heart disease, a navigator-gated, 3D whole-heart MRI during end-systole (ES) and end-diastole (ED), 2D short-axis cine MRI, and phase contrast MRI of the great arteries were acquired. Ventricular volumes were measured by using a 3D threshold-based segmentation for 3D whole-heart MRI and by using a simplified contouring for 2D cine MRI. The cardiac trigger delays of 3D whole-heart MRI were compared with those of a 2D cine MRI. The stroke volumes calculated from the ventricular volumes were compared with the arterial flow volumes, measured by phase contrast MRI.

RESULTS

The ES and ED trigger delays of whole-heart MRI were significantly less than cine MRI for both the left ventricle (-16.8 ± 35.9 ms for ES, -59.0 ± 90.4 ms for ED; < 0.001) and the right ventricle (-58.8 ± 30.6 ms for ES, -104.9 ± 92.7 ms for ED; < 0.001). Compared with the arterial flow volumes, 2D cine MRI significantly overestimated the left ventricular stroke volumes (8.7 ± 8.9 mL, < 0.001) and the 3D whole-heart MRI significantly underestimated the right ventricular stroke volumes (-22.7 ± 22.9 mL, < 0.001).

CONCLUSION

Three-dimensional whole-heart MRI is often subject to early timing of the ED phase, potentially leading to the underestimation of the right ventricular stroke volumes.