Guttman Michael A, Raval Amish N, Lederman Robert J, McVeigh Elliot R
Laboratory of Cardiac Energetics, National Institutes of Health, National Heart, Lung and Blood Institute, Bethesda, Maryland 20892-1061, USA.
J Magn Reson Imaging. 2008 Aug;28(2):538-42. doi: 10.1002/jmri.21409.
To develop an imaging and visualization technique for real-time magnetic resonance angiography (rtMRA) fully integrated with a real-time interactive imaging environment on a clinical MR scanner.
Intraarterial injections of contrast agent and imaging processing techniques were employed for rapid catheter-directed assessment of vessel patency and regional tissue perfusion. Operators can image multiple thin slices to maximize anatomic detail or use thick slice or projection imaging to maximize vessel coverage. Techniques in both pulse sequence and image processing were employed to ensure background suppression. Accumulation of maximum pixel values allows persistent display of bolus signal as it passes through the vessels and into tissues. Automatic brightness adjustment was used to ensure visibility at all stages of bolus passage.
Experimental intraarterial rtMRA of coronary, renal, and carotid arteries show that vessel trajectories and perfusion territories are well visualized in swine. Switching between standard real-time imaging and rtMRA imaging after contrast injection was easy to perform during a procedure without stopping the scanner.
The proposed technique facilitates visualization of intraarterial contrast injections using real-time MRI. Although designed for rapid deployment during rtMRI-guided interventional procedures, the technique may also be useful to supplement the study of vessel anatomy, flow, or perfusion.
开发一种成像与可视化技术，用于在临床磁共振扫描仪上实现与实时交互式成像环境完全集成的实时磁共振血管造影（rtMRA）。
采用动脉内注射造影剂和成像处理技术，对血管通畅性和局部组织灌注进行快速导管引导评估。操作人员可以对多个薄层进行成像，以最大化解剖细节，或者使用厚层或投影成像来最大化血管覆盖范围。采用脉冲序列和图像处理技术来确保背景抑制。最大像素值的累积允许在团注信号穿过血管并进入组织时持续显示。使用自动亮度调整以确保在团注通过的所有阶段都能清晰可见。
对猪的冠状动脉、肾动脉和颈动脉进行的实验性动脉内rtMRA显示，在猪体内血管走行和灌注区域清晰可见。在注射造影剂后，在不停止扫描仪的情况下，很容易在标准实时成像和rtMRA成像之间进行切换。
所提出的技术有助于使用实时MRI可视化动脉内造影剂注射。尽管该技术设计用于在rtMRI引导的介入手术中快速部署，但该技术也可能有助于补充血管解剖、血流或灌注的研究。
