Five-dimensional MRI incorporating simultaneous resolution of cardiac and respiratory phases for volumetric imaging.

摘要: Methods for measuring deformation and motion of the human heart in-vivo are crucial in assessment cardiac function. Applications ranging from basic physiological research, through early detection disease to follow-up studies, all rely on quality measurements dynamics. This thesis presents new improved magnetic resonance imaging methods acquisition, image reconstruction visualization deformation.As moves changes shape during synchronization dynamics is necessary. Here, a method resolve not only cycle but also respiratory presented. Combined with volumetric imaging, this produces five-dimensional data set two cyclic temporal dimensions. type reveals unique information, such as interventricular coupling different phases cycle.The acquisition can be sensitized motion, magnitude magnetization signal proportional local velocity or displacement. allows quantification which especially suitable functional study deformation. In work, an evaluation influence several factors signal-to-noise ratio presented displacement encoded imaging. Additionally, extension acquire multiple slices single breath hold presented.Magnetic usually associated long scan times, many exist shorten time while maintaining acceptable quality. One class involves acquiring sparse subset k-space. A special then necessary order obtain artifact-free image. family these techniques tailored dynamic k-t BLAST approach, incorporates data-driven prior knowledge suppress aliasing artifacts that otherwise occur sampling. original dimensions applied acquired full coverage cardio-respiratory cycles. Using technique, termed k-t2 BLAST, simultaneous reduction spatial resolution demonstrated. Further, loss fidelity when using approach investigated, proposed application function analysis.Visualization part chain. Scalar data, regular anatomical images, straightforward display. Myocardial strain strain-rate, however, tensor quantities do lend themselves direct visualization. The problem visualizing field approached work by combining displays degrees freedom overview scalar representation complete field. obtained iterated adaptive filtering noise field, creating continuous geometrical myocardial strain-rate field.The results provide opportunities function, areas chain;