Tasu J P, Jolivet O, Mousseaux E, Delouche A, Diebold B, Bittoun J
C.I.E.R.M., C.N.R.S.-URA 2212, Université Paris-Sud, Le Kremlin-Bicêtre, France.
Magn Reson Med. 1997 Jul;38(1):110-6. doi: 10.1002/mrm.1910380116.
Acceleration mapping can be conducted by replacing the bipolar gradient pulse of a velocity mapping sequence by a tripolar pulse. However, since the acceleration encoding pulse is longer, the image quality is altered by the requirement of a long echo time. Since Fourier encoding velocity imaging has been shown to be robust, this velocity mapping method was transformed into an acceleration mapping method. Four steps of the tripolar acceleration encoding gradient pulse were applied successively; acceleration was then obtained by Fourier transform after zero-filling. The accuracy of the method was assessed with a phantom giving a pulsatile flow. Acceleration maps of the ascending aorta and pulmonary artery were obtained in 10 healthy volunteers. The acceleration values measured were in the range of known physiologic values. The feasibility of Fourier encoding acceleration imaging was also demonstrated in four patients.
加速度映射可以通过用三极脉冲代替速度映射序列的双极梯度脉冲来进行。然而，由于加速度编码脉冲更长，长回波时间的要求会改变图像质量。由于傅里叶编码速度成像已被证明是可靠的，这种速度映射方法被转化为一种加速度映射方法。连续应用三极加速度编码梯度脉冲的四个步骤；然后在零填充后通过傅里叶变换获得加速度。用一个产生脉动流的体模评估该方法的准确性。在10名健康志愿者中获得了升主动脉和肺动脉的加速度图。测量的加速度值在已知生理值范围内。在4名患者中也证明了傅里叶编码加速度成像的可行性。
