School of Biological Sciences, The University of Western Australia, Perth, 6009 Western Australia, Australia
Oceans Institute, The University of Western Australia, Perth, 6009 Western Australia, Australia.
eNeuro. 2020 Aug 20;7(4). doi: 10.1523/ENEURO.0076-20.2020. Print 2020 Jul/Aug.
Contrast-enhanced X-ray imaging provides a non-destructive and flexible approach to optimizing contrast in soft tissues, especially when incorporated with Lugol's solution (aqueous IKI), a technique currently referred to as diffusible iodine-based contrast-enhanced computed tomography (diceCT). This stain exhibits high rates of penetration and results in excellent contrast between and within soft tissues, including the central nervous system. Here, we present a staining method for optimizing contrast in the brain of a cartilaginous fish, the brownbanded bamboo shark, , and a bony fish, the common goldfish, , using diceCT. The aim of this optimization procedure is to provide suitable contrast between neural tissue and background tissue(s) of the head, thereby facilitating digital segmentation and volumetric analysis of the central nervous system. Both species were scanned before staining and were rescanned at time (T) intervals, either every 48 h () or every 24 h (), to assess stain penetration and contrast enhancement. To compare stain intensities, raw X-ray CT data were reconstructed using air and water calibration phantoms that were scanned under identical conditions to the samples. Optimal contrast across the brain was achieved at T = 240 h for and T = 96 h for Higher resolution scans of the whole brain were obtained at the two optimized staining times for all the corresponding specimens. The use of diceCT provides a new and valuable tool for visualizing differences in the anatomic organization of both the central and peripheral nervous systems of fish.
对比增强 X 射线成像提供了一种非破坏性且灵活的方法来优化软组织的对比度，特别是与卢戈氏液（水性 IKI）结合使用时，这种技术目前被称为弥散碘基对比增强计算机断层扫描（diceCT）。这种染色剂具有很高的穿透率，可在软组织（包括中枢神经系统）之间和内部产生极好的对比度。在这里，我们介绍了一种使用 diceCT 优化软骨鱼（棕带竹鲨）和硬骨鱼（普通金鱼）大脑对比度的染色方法。该优化程序的目的是在脑组织和头部背景组织之间提供合适的对比度，从而便于对中枢神经系统进行数字分割和体积分析。在染色之前对两种物种进行了扫描，并在时间 (T) 间隔内以 48 小时 ( ) 或 24 小时 () 的间隔进行重新扫描，以评估染色剂的穿透率和对比度增强。为了比较染色强度，使用空气和水校准体模对原始 X 射线 CT 数据进行了重建，这些体模是在与样品相同的条件下扫描的。对于 和 ，在 T=240 h 和 T=96 h 时可以在整个大脑中实现最佳对比度。在优化的染色时间下，对所有对应标本的整个大脑进行了更高分辨率的扫描。diceCT 的使用为可视化鱼类中枢和外周神经系统的解剖组织差异提供了一种新的有价值的工具。
