NONINVASIVE MYOCARDIAL MOTION ANALYSIS WITH MRI

详细的心肌动力学知识是理解 正常的心脏生理和运动异常密切相关 与许多心脏疾病相关。我们已经学到了很多东西 关于心肌动力学的研究一直通过使用有创的 可以追踪单个心肌节段的技术。当前 非侵入性技术还不能准确地复制这些 数据，部分原因是它们不跟随单个数据段，并且可能 将体块运动与壁厚相混淆。而其他核磁共振方法可以提供 承诺通过使用 磁性心肌标记，它们具有有限的空间和时间 分辨率，无法检查整个心脏周期，需要 考试时间很长。我们建议克服这些限制 通过开发、评估和验证收购和 基于相衬磁共振心肌图的分析方法 速度。这种新方法允许任意位置的区域，如 小到几个立方毫米，回溯到 在整个心脏周期中，以d-D紧随其后。此外， 可以测量区域的瞬时应变、剪切、扭转和扭转。 而不需要复杂的模式识别算法。 该方法将通过使用幻影和 通过与动物和患者的荧光测量进行比较， 在手术时植入了不透射线的标记。 手术后的心肌动力学将在患者和 动物，以及正常和移植的心肌力学 人类的心脏将被评估。一旦得到验证，这项技术应该 让心肌运动的无创研究史无前例 分辨率和范围，并可提供给MRI中心 在世界各地。提出的相位对比磁共振成像技术可以 对正常心肌的认识有重大影响 功能，在患者的心脏病理评估中，以及在 治疗的选择、影响和时机。

Detailed knowledge of myocardial dynamics is central to understanding normal cardiac physiology and motion abnormalities are closely correlated with many cardiac pathologies. Much of what has been learned concerning myocardial dynamics has been though the use of invasive techniques which can track individual myocardial segments. Current noninvasive techniques have not been able to exactly reproduce these data, in part because they do not follow individual segments and may confuse bulk motion with wall thickening. While other MRI methods offer promise to partially address these limitations through the use of magnetic myocardial tagging, they have limited spatial and temporal resolution, are unable to examine the entire cardiac cycle, and require long examination times. We propose to overcome these limitations through the development, evaluation and validation of acquisition and analysis methods based on phase contrast MRI maps of myocardial velocity. This novel approach allows arbitrarily positioned regions, as small as a few cubic mm, to be selected retrospectively anywhere in the heart and followed in d-D throughout the entire cardiac cycle. Further, instantaneous regional strain, shear, torsion and twist can be measured directly without requiring sophisticated pattern recognition algorithms. The method will be thoroughly evaluated through the use of phantoms and by comparison with fluoroscopic measurements in animals and patients who have had radiopaque markers implanted at the time of surgery. Myocardial dynamics after surgery will be studied in patients and animals, and the myocardial mechanics of the normal and transplanted human heart will be evaluated. Once validated, this technique should allow the noninvasive study of myocardial motion with unprecedented resolution and scope, and can be made available to MRI centers throughout the world. The proposed phase contrast MRI techniques could have a significant impact in the understanding of normal myocardial function, in the evaluation of cardiac pathologies in patients, and in the choice, impact and timing of therapy.