Physiologic AV Valvular Insufficiency in Cine MR Imaging

ABSTRACT

PURPOSE: To give a help in the interpretation of cardiac cine-MR examination, the extent, shape, and timing of appearance of signal void regions near atrioventricular(A-V) valve prospectively evaluated in the healthy population. MATERIALS AND METHODS: Using an axial gradient-echo technique with small flip angle, repetition time(TR) of 36 msec and echo time(TE) of 22 msec, 20 volunteers without known valvular abnormalities undertook cardiac cine-MR imaging including atrioventricualr valve areas. RESULTS: Transient signal void was observed within the atrium near the tricuspid(13/20 = 65%) and mitral valves(9/20 = 45%), respectively, which is so called "physiologic atrioventricular valvular insufficiency". Eight subjects revealed the signal void areas near both tricuspid and mitral valves but, 5 subjects didnot show any evidences of physiologic insufficiency. This physiologic condition does not extend more than lcm proximal to A-V valve plane and is generally observed only during early systole. Its morphology is semilunar or triangular configuration with the base to the valve plane in most cases of normal tricuspid insufficiency and small globular appearance in most cases of normal mitral insufficiency. CONCLUSION: Awareness of normal signal void areas near the A-V valve and their characteristics is critical in the interpretation of cardiac cine MR examinations and maybe helpfal in the study of the normal cardiac physiology.