Aims: To explore the potentiality of cardiovascular magnetic resonance (CMR) in the quantitative evaluation of mitral valve annulus (MVA) and tricuspid valve annulus (TVA) morphology and dynamics.
Methods and results: CMR was performed in 13 normal subjects and 9 patients with mitral (n = 7) or tricuspid regurgitation (n = 2), acquiring cine-images in 18 radial long-axis planes passing through the middle of MVA or TVA. A novel algorithm was used to obtain dynamic three-dimensional (3D) reconstruction of MVA and TVA. Analysis was feasible in all cases, allowing accurate 3D annular reconstruction and tracking. The 3D area increased from systole [MVA, median = 10.0 cm(2) (first quartile = 8.6, third quartile = 11.4); TVA, 11.2 cm(2) (8.8-13.2)] to diastole [MVA, 10.6 cm(2) (9.4, 11.7); TVA, 11.9 cm(2) (9.2-13.5)], with TVA larger than MVA. While the longest diameter showed similar systolic and diastolic values, the shortest diameter elongated from systole [MVA, 30 mm (29-33); TVA, 33 mm (31-36)] to diastole [MVA, 31 mm (29-32); TVA, 36 mm (33-39)]. Also, TVA became more circular than MVA. TVA showed lower peak systolic excursion in the septal [15.9 mm (13.0-18.5)] and anterior regions [17.9 mm (12.2-20.7)] compared with the posterior [21.9 mm (18.6-24.0)] segment. Values in MVA were smaller than in TVA, slightly higher in anterior [11.2 mm (9.5-13.0)] than in posterior [12.4 mm (10.2-14.6)] segments. Valvular regurgitation was associated with enlarged, flattened, and more circular annuli.
Conclusion: The applied method was feasible and accurate in normal and regurgitant valves, and may potentially have an impact on diagnosis, improvement of surgical techniques and design of annular prostheses.
Keywords: Annular geometry; Cardiovascular magnetic resonance; Mitral valve annulus; Tricuspid valve annulus.