Fast phase contrast cardiac magnetic resonance imaging: Improved assessment and analysis of left ventricular wall motion

Purpose. To evaluate the use of CINE phase contrast magnetic resonance imaging (MRI) to assess and characterize left ventricular wall motion by two- or three -directional velocity vector fields that reflect the temporal evolution of myocardial velocities over the whole cardiac cycle. Material and Methods: A fast imaging protocol is presented that permits the assessment of the pixel-wise full in-plane velocity information of the beating heart within a single breath-hold measurement. Temporal resolution of the acquired images is improved by the use of high-speed gradients and application of view sharing to black blood k-space segmented gradient echo imaging. A novel tool for data analysis is presented based on correlating locally different myocardial motion patterns to averaged left ventricular velocities reflecting nonpathological myocardial function. Results: Measurement protocol and postprocessing options were evaluated in a study with 16 normal volunteers. Simulations showed that correlation analysis can be used to differentiate regions with altered velocity waveforms from global radial velocities. Results of patient examinations are presented on an exemplary basis and demonstrate that correlation analysis provides an effective method for identification and classification of myocardial dynamics. Conclusion: Within the framework of our volunteer and patient examinations, fast phase contrast cardiac MRI has proven to be a reliable method to assess and analyze myocardial performance on the basis of two-directional velocity vector fields.