Wilkinson Steven J, Rogers Keith D, Hall Chris J, Round Adam R
Department of Materials and Medical Sciences, Cranfield University, Shrivenham, Swindon, Wiltshire SN6 8LA, UK.
Phys Med Biol. 2007 May 7;52(9):2409-23. doi: 10.1088/0031-9155/52/9/006. Epub 2007 Apr 10.
In this paper we report on the extension of the technique of mapping small angle x-ray scatter (SAXS) across a soft material specimen several millimetres square. In the conventional SAXS mapping technique a pencil beam of x-rays is raster scanned over the specimen with the scatter pattern recorded from each point in the raster. In our technique a wide, parallel beam is used, speeding up the data collection time considerably. An image processing algorithm is used to separate the scatter pattern features from individual points along the line of the beam. To test the efficacy of the technique a phantom was constructed using gelatin and rat tail tendon collagen. Collagen fibres in the phantom were arranged in quarters horizontally, diagonally and vertically leaving one quarter with just gelatin. The phantom was used to collect both raster scanned sets of SAXS patterns spaced at 0.25 mm horizontally and vertically and also a wide beam data set. The width of the beam in this case was approximately 7 mm. Using the third-order diffraction of rat tail tendon intensity data were gathered from each SAXS pattern and used to construct a map. Data from the raster scan image and that from the wide beam are compared. Finally using a phantom made from dehydrated rat tail tendon and paraffin wax a tomographic slice constructed using data from SAXS patterns is shown.
在本文中，我们报告了将小角X射线散射（SAXS）映射技术扩展到对几平方毫米的软材料样本进行检测的情况。在传统的SAXS映射技术中，X射线铅笔束在样本上进行光栅扫描，并记录光栅中每个点的散射图案。在我们的技术中，使用了宽平行光束，大大加快了数据收集时间。使用一种图像处理算法来从沿光束线的各个点分离散射图案特征。为了测试该技术的有效性，使用明胶和大鼠尾腱胶原蛋白构建了一个模型。模型中的胶原纤维水平、对角和垂直排列成四分之一，其中四分之一仅含明胶。该模型用于收集水平和垂直间距为0.25毫米的光栅扫描SAXS图案集，以及一个宽光束数据集。在这种情况下，光束宽度约为7毫米。利用大鼠尾腱的三阶衍射，从每个SAXS图案收集强度数据并用于构建图谱。比较了光栅扫描图像的数据和宽光束的数据。最后，展示了使用脱水大鼠尾腱和石蜡制成的模型，以及使用SAXS图案数据构建的断层切片。
