Rapid MR imaging of blood flow with a phase-sensitive, limited-flip-angle, gradient recalled pulse sequence: preliminary experience.
Rapid MR imaging of blood flow with a phase-sensitive, limited-flip-angle, gradient recalled pulse sequence: preliminary experience.
复制标题
使用相敏、有限翻转角、梯度回忆脉冲序列对血流进行快速 MR 成像：初步经验。
DOI：
10.1148/radiology.176.1.2353099
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发表时间：
1990
期刊：
影响因子：
19.7
通讯作者：
Riederer,SJ
中科院分区：
文献类型：
--
作者：
Spritzer,CE;Pelc,NJ;Lee,JN;Evans,AJ;Sostman,HD;Riederer,SJ
为了快速评估血流，对一个有限翻转角、梯度回忆的脉冲序列进行了修改，在连续重复的相同相位编码步骤中获得两个视图。一个视图是通过第一矩流补偿获得的，而第二个视图是通过沿一个方向的可选流编码（非零第一矩）获得的。沿着编码方向流动的血液在两个视图之间获得相位差，导致信号依赖于流动的方向和速度。静止组织不发生相变。因此，两个视图之间的相移产生的图像在空间上呈现了流的方向和速度。使用24毫秒的重复时间，256 X 128矩阵和两次激励，每个位置的数据采集在13秒内完成（在每个位置生成幅度图像和流量图像）。流影生成的图像证实了该方法的准确性。23名受试者的初步临床证据表明，该方法可用于评估门静脉高压，区分动脉和静脉血流，区分慢血流和血栓，并确认血栓的存在。这种方法似乎是一种快速、简便的评估大血管血流的方法。
To assess blood flow rapidly, a limited-flip-angle, gradient recalled pulse sequence was modified to acquire two views at the same phase-encoding step in successive repetitions. One view is obtained with first-moment flow compensation, while the second view is obtained with selectable flow encoding (non-zero first moment) along one direction. Blood flowing along the encoded direction acquires a phase difference between the two views, resulting in signal dependent on both direction and speed of flow. Stationary tissues undergo no phase change. Therefore, the phase shift between the two views produces an image that spatially renders flow direction and velocity. With a 24-msec repetition time, a 256 X 128 matrix, and two excitations, data acquisition is completed in 13 seconds per location (both a magnitude image and a flow image are produced at each location). Images generated with flow phantoms confirmed the accuracy of this method. Preliminary clinical evidence in 23 human subjects suggests that this method is useful in evaluating portal hypertension, distinguishing arterial from venous flow, distinguishing between slow flow and clot, and confirming the presence of clot. This method appears to be a fast, easy way to assess blood flow in large vessels.