Aldefeld Bernd, Börnert Peter, Keupp Jochen
Philips Research Laboratories, Hamburg, Germany.
Magn Reson Med. 2006 May;55(5):1210-6. doi: 10.1002/mrm.20876.
A method is presented for 3D MRI in an extended field of view (FOV) based on continuous motion of the patient table and an efficient acquisition scheme. A gradient-echo MR pulse sequence is applied with lateral (left-right (L/R)) frequency-encoding direction and slab selection along the direction of motion. Compensation for the table motion is achieved by a combination of slab tracking and data alignment in hybrid space. The method allows fast k-space coverage to be achieved, especially when a short sampling FOV is chosen along the direction of table motion, as is desirable for good image quality. The method can be incorporated into different acquisitions schemes, including segmented k-space scanning, which allows for contrast variation with the use of magnetization preparation. Head-to-toe images of volunteers were obtained with good quality using 3D spoiled gradient-echo sequences. As an example of magnetization-prepared imaging, fat/water separated images were acquired using chemical shift selective (CHESS) presaturation pulses.
本文提出了一种基于患者检查床连续运动和高效采集方案的扩展视野(FOV)三维磁共振成像(MRI)方法。采用梯度回波MR脉冲序列,频率编码方向为横向(左右(L/R)),并沿运动方向进行层面选择。通过层面跟踪和混合空间中的数据对齐相结合来补偿检查床运动。该方法能够实现快速的k空间覆盖,特别是当沿检查床运动方向选择较短的采样视野时,这对于获得良好的图像质量是很理想的。该方法可纳入不同的采集方案,包括分段k空间扫描,这允许通过使用磁化准备来改变对比度。使用三维扰相梯度回波序列获得了志愿者从头到脚的高质量图像。作为磁化准备成像的一个例子,使用化学位移选择性(CHESS)预饱和脉冲采集了脂肪/水分离图像。