VELOCITY MAPPING Measurement of Left Ventricular Velocities: Phase Contrast MRI Velocity Mapping Versus Tissue-Doppler-Ultrasound in Healthy Volunteers

The aim of this study was the comparison of phase contrast magnetic resonance imaging (PCMRI) measurements of left ventricular velocities in a physiological in vivo setting with tissue-Doppler-ultrasound (tissue Doppler imaging: TDI) data in healthy volunteers. Images were acquired in short axis view using a flow compensated black blood k-space segmented gradient echo sequence. Velocity encoding was performed by adding a bipolar gradient after each rf-pulse to the otherwise identical pulse sequences. Full in-plane velocity information of the moving heart was obtained in 16 heartbeats within one breath-hold measurement. Twenty-nine healthy volunteers (mean age=25 years) were examined with both imaging modalities. Both PCMRI and TDI demonstrate a biphasic profile of radial velocities over the cardiac cycle. Intraindividual comparison of left ventricular velocity data acquired using PCMRI and TDI show a very good correspondence with r-values of 0.97. The in vivo study in 29 healthy volunteers demonstrates a high validity of time-resolved phase contrast measurements for the analysis of left ventricular myocardial velocities