Portman M A
Department of Pediatrics, College of Human Medicine, Michigan State University, East Lansing 48824-1317.
Semin Ultrasound CT MR. 1992 Aug;13(4):274-90.
At the current state of the art, cardiothoracic MR angiography offers the clinician information that is supplemental to that provided by other noninvasive imaging techniques. Indeed, in some areas MR angiography will likely surpass currently used methods as the technique of choice. Specifically, measurement of cardiac output, pulmonary blood flow, and lung perfusion can be performed relatively accurately and simply during a brief MR examination. Both standard spin-echo and angiographic evaluation of the thoracic aorta provide qualitative images with superior resolution. Additionally, development of pulmonary artery angiography is progressing rapidly and may soon be clinically useful. Phase incoherence caused by complex flow and resulting in a signal void is useful for location and qualitative assessment of abnormal flow jets induced by stenoses. However, this phenomenon represents the major limitation to quantitative assessment of flow abnormalities. Methods to increase signal to noise and/or reduce phase incoherence must be developed before MR angiography can be used effectively to assess abnormal flow conditions.
在当前的技术水平下，心胸磁共振血管造影为临床医生提供的信息是对其他非侵入性成像技术所提供信息的补充。事实上，在某些领域，磁共振血管造影很可能会超越目前使用的方法，成为首选技术。具体而言，在一次简短的磁共振检查过程中，可以相对准确且简单地测量心输出量、肺血流量和肺灌注。标准自旋回波和胸主动脉血管造影评估均可提供具有卓越分辨率的定性图像。此外，肺动脉血管造影的发展正在迅速推进，可能很快就会在临床上发挥作用。由复杂血流导致的相位不一致并产生信号缺失，这对于狭窄引起的异常血流喷射的定位和定性评估很有用。然而，这种现象是血流异常定量评估的主要限制。在磁共振血管造影能够有效用于评估异常血流状况之前，必须开发出增加信噪比和/或减少相位不一致的方法。
