Santori E M, Toga A W
Department of Neurology, UCLA School of Medicine 90024.
J Neurosci Methods. 1993 Nov;50(2):187-96. doi: 10.1016/0165-0270(93)90007-e.
Superpositioning of multiple 3-dimensional digital volumes is essential to extending neuroimaging capabilities from single-subject analysis to group evaluation. In this study, 6 rat heads were cryoplaned and digital images of the specimen blockface were organized into data volumes. The midline plane of each brain guided coronal and horizontal rotations and medial-lateral positioning. Four different methods of determining sagittal rotation, dorsoventral position, and anteroposterior position were tested. The first technique uses lambda and bregma as fiducial points; the second method employs bony sutures in the base of the skull; and the third strategy fits both sets of alignments points. The fourth method differs from the previous landmark-based approaches by employing cross-correlation of image densities. A composite of midsagittal cutplanes through the volumes aligned by the first method revealed significant misalignment. Use of ventral fiducials resulted in improved correlation statistics for orthogonal cutplanes through the volumes and significantly reduced positional variability of anteroposterior landmarks. Combining dorsal and ventral fiducials produced a slight improvement in midsagittal image correlation but had mixed effects on landmark variability. Following the fourth method of registration, correlation statistics and the alignment of reference points were similar to those obtained with the 4-point approach.
将多个三维数字体积进行叠加对于将神经成像能力从单主体分析扩展到组评估至关重要。在本研究中，对6个大鼠头部进行了冷冻切片，并将标本块面的数字图像整理成数据体积。每个大脑的中线平面引导冠状面和水平面旋转以及内外侧定位。测试了四种确定矢状面旋转、背腹位置和前后位置的不同方法。第一种技术使用枕骨大孔和前囟作为基准点；第二种方法采用颅底的骨缝；第三种策略拟合两组对齐点。第四种方法与之前基于地标的方法不同，它采用图像密度的互相关。通过第一种方法对齐的体积的正中矢状切面合成显示出明显的未对齐。使用腹侧基准点可改善通过体积的正交切面的相关统计，并显著降低前后地标位置的变异性。结合背侧和腹侧基准点可使正中矢状面图像相关性略有改善，但对地标变异性有混合影响。按照第四种配准方法，相关统计和参考点的对齐与四点法获得的结果相似。
