Objective: Our aim was to assess the feasibility and image quality of dynamic cine-mode imaging of the mitral valve using retrospectively ECG-gated 16-MDCT.
Subjects and methods: Contrast-enhanced MDCT was performed in 37 patients who have a normal mitral valve, as shown on transesophageal echocardiography. Twenty CT data sets covering the valve apparatus were reconstructed every 5% step of the R-R interval. Multiplanar reconstructions were performed in the parallel short axis and perpendicular long axis of the left ventricle. Two independent blinded reviewers evaluated the image quality for dynamic cine-mode visualization of the valve components in systole and diastole and during the transitional phases in between.
Results: Interobserver agreement for image quality ratings of valve components in all cardiac cycle phases ranged from good to excellent. Image quality for the visualization of valve leaflets, apposition zone, commissures, and mitral annulus (ranging from adequate to excellent) was significantly superior on perpendicular plane images than on parallel plane images for all cardiac phases (p < 0.05). Tendinous cords were visualized on both perpendicular and parallel planes with bad to adequate quality, whereas visualization of the papillary muscles was adequate to excellent on both imaging planes. Visualization of each valve component was superior in systole and diastole in both imaging planes as compared with the transitional phases (p <0.001).
Conclusion: Noninvasive cine-mode imaging of the mitral valve using retrospectively ECG-gated MDCT is feasible and allows accurate visualization of the moving valve. Perpendicular long-axis reconstructions yield images of superior quality when compared with the short-axis reconstructions and enable a determination of its functional morphology.