Jochimsen Thies H, Norris David G
Max-Planck-Institute of Cognitive Neuroscience, Stephanstr. 1a, D 04103, Leipzig, Germany.
MAGMA. 2002 Mar;14(1):50-5. doi: 10.1007/BF02668187.
The feasibility of imaging a curved slice with a single-shot technique so that the reconstructed image shows an un-warping of the slice is examined. This could be of practical importance when the anatomical structures of interest can be more efficiently covered with curved slices than with a series of flat planes. One possible example of such a structure is the cortex of the human brain. Functional imaging would especially benefit from this technique because several planar images can be replaced by a few curved slice images. A method is introduced that is based on multidimensional pulses to excite the desired curved slice profile. A GRASE imaging sequence is then applied that is tailored to the k-space representation of the curved slice. This makes it possible to capture the in-plane information of the slice with a single-shot technique. The method presented is limited to slices that are straight along one axis and can be approximated by a polygon. Reconstruction is performed using a simple numeric Fourier integration along the curved slice. This leads to an image that shows the desired un-warped representation of the slice. Experimental results obtained with this method from healthy volunteers are presented and demonstrate the feasibility of the proposed technique.
研究了使用单次激发技术对弯曲切片进行成像,以使重建图像显示切片无扭曲的可行性。当感兴趣的解剖结构用弯曲切片比用一系列平面能更有效地覆盖时,这可能具有实际重要性。这种结构的一个可能例子是人类大脑的皮质。功能成像将特别受益于该技术,因为几个平面图像可以由几个弯曲切片图像代替。介绍了一种基于多维脉冲来激发所需弯曲切片轮廓的方法。然后应用一种针对弯曲切片的k空间表示量身定制的GRASE成像序列。这使得用单次激发技术捕获切片的平面内信息成为可能。所提出的方法限于沿一个轴是直的且可用多边形近似的切片。使用沿弯曲切片的简单数值傅里叶积分进行重建。这会得到一幅显示切片所需无扭曲表示的图像。展示了用该方法从健康志愿者获得的实验结果,并证明了所提技术的可行性。