使用三回波读出的稳态自由进动(SSFP)和梯度回波(GRE)相位对比成像。
SSFP and GRE phase contrast imaging using a three-echo readout.
作者信息
Nielsen Jon-Fredrik, Nayak Krishna S
机构信息
Magnetic Resonance Engineering Laboratory, Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089-2564, USA.
出版信息
Magn Reson Med. 2007 Dec;58(6):1288-93. doi: 10.1002/mrm.21276.
A technique for rapid in-plane phase-contrast imaging with high signal-to-noise ratio (SNR) is described. Velocity-encoding is achieved by oscillating the readout gradient, such that each 2DFT phase-encode is acquired three times following a single RF slice-selective excitation. Three images are reconstructed, from which both flow velocity and local resonance offset are calculated. This technique is compatible with both gradient-recalled echo (GRE) and balanced steady-state free precession (SSFP) imaging using a single steady-state. The proposed technique enables 1D velocity mapping with 40% higher temporal resolution and 80% higher SNR, compared to conventional PC-MRI using bipolar velocity-encoding gradient pulses.
本文描述了一种用于快速平面内相位对比成像的技术,该技术具有高信噪比(SNR)。通过振荡读出梯度来实现速度编码,使得在单次射频切片选择性激发后,每个二维傅里叶变换(2DFT)相位编码被采集三次。重建三幅图像,从中计算出流速和局部共振偏移。该技术与使用单一稳态的梯度回波(GRE)和平衡稳态自由进动(SSFP)成像均兼容。与使用双极速度编码梯度脉冲的传统相位对比磁共振成像(PC-MRI)相比,所提出的技术能够实现具有高40%的时间分辨率和高80%的信噪比的一维速度映射。