Magnetic resonance imaging of cardiacvascular function

我们的实验室已经应用了一种称为DENSE的高功率MRI技术来详细成像心脏壁和颈动脉壁运动。DENSE是Displacement ENcoding with Stimulated Echo的缩写，是我们实验室的首创。今年，我们成功开发了心脏和血管壁应变和运动映射的扫描协议和数据处理软件，并在正常志愿者和患者中进行了测试。这种发展的一个应用是测量早期和中期心脏壁的顺应性或硬度，这是心脏腔室如何在心脏腔室中快速填充到体积的关键因素。我们还使用这种技术来精确地测量由于振荡的心肌内血压和冠状动脉血流之间的相互作用而引起的心壁组织体积的波动。这些发现发表在《医学磁共振》杂志上，并在会议上发表。 我们的实验室还观察到一个新的现象，在自旋回波磁共振成像的心脏时，血池造影剂注入动物-图像强度的依赖于扫描仪的磁场方向。我们发现了这一现象背后的机制，并在大鼠模型中获得了初步数据，表明这是一种非常有效的方法来绘制跳动心脏中的毛细血管结构，并通过推断肌纤维结构。这可能是体内微血管结构成像的最有效方法。这一发现也发表在《Magnetic Resonance in Medicine》杂志上。

Our lab has applied a high-power MRI technique called DENSE to image heart wall and carotid artery wall motion in detail. DENSE stands for Displacement ENcoding with Stimulated Echo and is pioneered in our lab. We successfully developed this year the scan protocol and data processing software for heart and blood vessel wall strain and motion mapping, and tested them in normal volunteers and patients. One application of this development is to measure the compliance or stiffness of the heart wall in early and mid diastole, which is a key factor in how the heart chambers rapidly fills to volume in diastole. We also used this technique to accurately measure the fluctuation of tissue volume in the heart wall due from the interaction between the oscillating intramyocardial blood pressure and coronary blood flow. These findings are published in the journal Magnetic Resonance in Medicine and presented in conferences. Our lab also observed a new phenomenon in spin-echo MRI of the heart when a blood-pool contrast agent is infused into the animal - a dependence of the image intensity on the direction of the scanner's magnetic field. We found the mechanism behind the phenomenon and with preliminary data in a rat model showed that it is a very effective way to map the capillary structure, and by inference muscle fiber structure, in a beating heart. This is probably the most effective way of imaging microvascular structure in vivo. This finding is also published in the journal Magnetic Resonance in Medicine.