Evaluation of the cortical structure in high resolution CT images of lumbar vertebrae by analysing low bone mineral density clusters and cortical profiles.
Evaluation of the cortical structure in high resolution CT images of lumbar vertebrae by analysing low bone mineral density clusters and cortical profiles.
复制标题
通过分析低骨矿物质密度簇和皮质轮廓来评估腰椎高分辨率 CT 图像中的皮质结构。
DOI：
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发表时间：
1997
影响因子：
2.6
通讯作者：
H. Peitgen
中科院分区：
文献类型：
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作者：
M. Haidekker;R. Andresen;C. Evertsz;D. Banzer;H. Peitgen
骨小梁的结构分类对骨质疏松症的诊断具有重要的临床意义。皮质骨密度（BMD）的评估和皮质结构的分析是必要的，因为皮质也受到骨质疏松症的影响。我们描述了一种自动分类的方法，从其结构上的高分辨率（HR）CT图像的皮质。该方法基于皮质中具有低BMD的区域的分布。提出了两种不同的方法，一种是使用皮质嵴的灰度分布，另一种是评估低BMD的连接区域（簇）的分布。即位于某一阈值以下的区域。在22个腰椎的HRCT图像中，在该阈值线的不同位置处确定皮质强度轮廓与水平线的交叉点的数量。在某个位置，有一个局部最大值的交叉点的数量是38%以上的病例。最大值显示与皮质BMD的中度相关性，rni = -0.72（p < 0.0001）。相对于阈值T确定像素值低于某一阈值的连接区域（簇）的数目nc。得到的函数nc（T）示出了稍微低于相应图像的平均灰度值的相对最大值。该曲线取决于骨质疏松的程度：最大值的高度（即最大聚类数ncmax）可以区分不同程度的骨质疏松，ncmax与皮质BMD的相关性为ncmax = -0.84（p < 0.0001）。
The structural classification of trabecular bone is of considerable clinical importance for the diagnosis of osteoporosis. Assessment of the cortical bone mineral density (BMD) and analysis of cortical structure is necessary because the cortex is also affected by osteoporosis. We describe a method for the automatic classification of the cortex from its structure on high resolution (HR) CT images. The method is based on the distribution of areas with low BMD in the cortex. Two different approaches are presented; one uses the grey scale profile of the cortical ridge, and the other one evaluates the distribution of connected regions (clusters) of low BMD. i.e. areas that lie below a certain threshold value. In HRCT images from 22 lumbar vertebrae, the number of intersections of the cortical intensity profile with a horizontal line was determined at various positions of this threshold line. At a certain position, there was a local maximum in the number of intersections which was 38% higher in the osteoporotic cases. The maximum shows a moderate correlation with the cortical BMD of rni = -0.72 (p < 0.0001). The number nc of connected regions (clusters) with pixel values below a certain threshold value was determined in relation to the threshold value T. The resulting function nc(T) shows a relative maximum slightly below the average grey scale value of the respective image. The curve depends on the degree of osteoporosis: the height of the maximum (i.e. the maximal number of clusters ncmax) allows distinction to be made between different degrees of osteoporosis, and ncmax shows a correlation with the cortical BMD of rnc = -0.84 (p < 0.0001).