Lee H M, Wang Y
Department of Radiology, Cornell University Medical College, New York, New York 10021, USA.
Magn Reson Med. 1998 Jul;40(1):99-104. doi: 10.1002/mrm.1910400114.
A bolus chase three-dimensional (3D) MR digital subtraction angiography (MRDSA) technique was implemented using dynamic k-space filling. This technique permits rapid 3D arterial imaging of the entire lower extremity at multiple stations using a single intravenous injection. Image acquisition at the first (most proximal) station starts from the edge of k-space and ends in the center of k-space (edge-center order). Image acquisition for middle stations starts from the edge of k-space, arrives at the center of k-space at the middle of data acquisition, and ends at the edge of k-space (edge-center-edge order). Image acquisition for the last station starts from the center of k-space and ends at the edge of k-space (center-edge order). This dynamic k-space filling minimizes contrast dose and motion artifacts. Bolus chase 3D MRDSA was performed on four normal volunteers and three patients using a multiple-phase 3D fast gradient-echo sequence, 25-ml gadolinium dose, and a prototype stepping table. Total bolus chase 3D acquisition time was 46 s. Mask subtraction using both complex and magnitude subtraction was performed. Complex subtraction was found to be necessary for proper delineation of arteries below the aortic bifurcation. Diagnostic results were consistently obtained for all subjects.
采用动态k空间填充技术实施团注追踪三维（3D）磁共振数字减影血管造影（MRDSA）。该技术允许通过单次静脉注射在多个部位对整个下肢进行快速3D动脉成像。第一个（最近端）部位的图像采集从k空间边缘开始，在k空间中心结束（边缘-中心顺序）。中间部位的图像采集从k空间边缘开始，在数据采集中期到达k空间中心，并在k空间边缘结束（边缘-中心-边缘顺序）。最后一个部位的图像采集从k空间中心开始，在k空间边缘结束（中心-边缘顺序）。这种动态k空间填充可将对比剂剂量和运动伪影降至最低。对4名正常志愿者和3名患者使用多期3D快速梯度回波序列、25毫升钆剂剂量和一个原型步进台进行团注追踪3D MRDSA。团注追踪3D采集总时间为46秒。使用复数减法和幅度减法进行掩模减法。发现复数减法对于正确描绘主动脉分叉以下的动脉是必要的。所有受试者均获得了一致的诊断结果。
