关键词: 磁共振成像(MRI), 黑血, 变延迟进动定制激发(DANTE)序列, 梯度放大器(GPA)

Abstract: Delays alternating with nutation for tailored excitation (DANTE) is often used as the preparation sequence in black blood imaging. After applying trains of small angle DANTE excitation pulse along with a gradient, the protons in blood flow and static tissues reach different steady states and thus have differente signal intensity. The static tissues shows dark strips, whose width is related to the product of the gradient amplitude and the duration of the DANTE sequence block. The larger the product is, the narrower the stripes are. A better suppression of flowing spins also require larger gradient amplitude×DANTE sequence block duration product and longer preparation time of the entire DANTE sequence module. As such, a high-performance gradient system is often required for this method. However, gradient amplifier (GPA) has limitations in reality. To solve this problem, we proposed here an optimized gradient for DANTE sequence in both the readout direction and slice rotation. The results demonstrated that a better black blood effect could be obtained by using the optimized method.

Key words: magnetic resonance imaging (MRI), black blood, delays alternating with nutation for tailored excitation (DANTE) sequence, gradient amplifier (GPA)