Quantitative MR signal behavior in cardiac cine loops as a function of heart rate.

To evaluate the heart cycle-dependent signal intensity changes in the cardiac chambers, the aorta, and the pulmonary artery, five healthy volunteers were studied with gradient-echo magnetic resonance cine loops at different heart rates. Quantitative evaluation of signal intensity on each side of the cardiac valves showed that there were changes in signal intensity due to section-entry and spin-phase phenomena but none due to the increase in heart rate. The authors conclude that there is no heart rate-dependent signal loss in healthy persons that simulates valvular dysfunction, thus suggesting that signal intensity change can be used as an indicator for this disease, independent of heart rate.