Steinmetz H, Huang Y, Seitz R J, Knorr U, Schlaug G, Herzog H, Hackländer T, Freund H J
Department of Neurology, Heinrich-Heine-University Düsseldorf, Germany.
J Cereb Blood Flow Metab. 1992 Nov;12(6):919-26. doi: 10.1038/jcbfm.1992.128.
We have developed, validated, and employed a technique of retrospective spatial alignment and integrated display of positron emission tomographic (PET) and high-resolution magnetic resonance (MR) brain images. The method was designed to improve the anatomical evaluation of functional images obtained from single subjects. In the first computational step, alignment of PET and MR data sets is achieved by iteratively matching in three orthogonal views the outermost scalp contours derived from front-to-back projections of each data set. This procedure avoids true three-dimensional modeling, runs without user interaction, and tolerates missing parts of the head circumference in the image volume, as usually the case with PET. Thereafter, high-resolution MR sections corresponding to the PET slices are reconstructed from the spatially transformed MR data. In a phantom study of this method, PET/MR alignment of the phantom's surface was accurate with average residual misfits of 2.17 to 2.32 mm as determined in three orthogonal planes. In-plane alignment of the phantom's insertion holes was accurate with an average residual misfit of 2.30 mm. In vivo application in six subjects allowed the individual anatomical localization of regional CBF (rCBF) responses obtained during unilateral manual exploration. In each subject, the maxima of the rCBF activations in the hand area were precisely allocated to gray matter in the anterior or posterior wall of the central sulcus. The configuration of the rCBF responses closely followed the gyral structures. The technique provided a better topographical understanding of rCBF changes in subtraction images of PET activation studies. It opens the perspective for studies of structural-functional relationships in individual subjects.
我们已经开发、验证并应用了一种回顾性空间对齐技术，用于正电子发射断层扫描（PET）和高分辨率磁共振（MR）脑图像的整合显示。该方法旨在改善对单个体受试者功能图像的解剖学评估。在第一个计算步骤中，通过在三个正交视图中迭代匹配从每个数据集的前后投影得出的最外侧头皮轮廓，实现PET和MR数据集的对齐。此过程避免了真正的三维建模，无需用户交互即可运行，并且可以容忍图像体积中头围部分的缺失，PET图像通常就是这种情况。此后，从空间变换后的MR数据中重建与PET切片相对应的高分辨率MR切片。在该方法的体模研究中，体模表面的PET/MR对齐准确，在三个正交平面中确定的平均残余失配为2.17至2.32毫米。体模插入孔的平面内对齐准确，平均残余失配为2.30毫米。在六名受试者中的体内应用允许对单侧手动探索期间获得的区域脑血流量（rCBF）反应进行个体解剖定位。在每个受试者中，手部区域rCBF激活的最大值被精确地定位到中央沟前壁或后壁的灰质。rCBF反应的配置紧密跟随脑回结构。该技术为PET激活研究的减法图像中rCBF变化提供了更好的地形学理解。它为个体受试者的结构-功能关系研究开辟了前景。
