[Morphological and function of normal mitral valve: correlation of CT features and cardiac cycle phase].

OBJECTIVE: To observe the changes of morphology and functions of the mitral valve during the cardiac cycle with a 64-detector row CT. METHODS: The hearts of 40 normal adults were scanned with a 64-detector row CT. Ten time phases in the cardiac cycle were reconstructed. The morphologic features of the mitral valve in different phases were analyzed using the volume rendering technique (VRT). The diameter and area of the mitral annular and the mitral valve, and the open angle of the mitral valve were measured at the cardiac H-long axis and the short-axis. RESULTS: The maximal diameter and area of the mitral annular and the mitral valve appeared in late diastole, with a value of (29.3 +/- 3.5) mm and (962.8 +/- 149.3) mm2, and (36.5 +/- 7.3) mm and (647.0 +/- 162.3) mm2, respectively. The maximal open angles also appeared in late diastole, with a value of (68.3 +/- 5.61) degrees and (55.9 +/- 5.4) degrees, for the anterior and posterior valves respectively. The minimal diameter and area of the mitral annular and open angles of the anterior and posterior valves appeared in mid-systole, with a value of (9.8 +/- 1.7) mm and (76.2 +/- 27.3) mm2, and (11.5 +/- 2.8) degrees and (9.6 +/- 2.8) degrees, respectively. CONCLUSION: The morphologic and functional changes of mitral valve during the cardiac cycle can be detected by the 64-detector row CT.