Volkau Ihar, Puspitasari Fiftarina, Nowinski Wieslaw L
Biomedical Imaging Laboratory, Agency for Science, Technology and Research (ASTAR), 30 Biopolis Street, #07-01, Matrix, Singapore 138671.
Int J Biomed Imaging. 2010;2010:674582. doi: 10.1155/2010/674582. Epub 2010 May 17.
We present a mathematical frame to carry out segmentation of cerebrospinal fluid (CSF) of ventricular region in computed tomography (CT) images in the presence of partial volume effect (PVE). First, the image histogram is fitted using the Gaussian mixture model (GMM). Analyzing the GMM, we find global threshold based on parameters of distributions for CSF, and for the combined white and grey matter (WGM). The parameters of distribution of PVE pixels on the boundary of ventricles are estimated by using a convolution operator. These parameters are used to calculate local thresholds for boundary pixels by the analysis of contribution of the neighbor pixels intensities into a PVE pixel. The method works even in the case of an almost unimodal histogram; it can be useful to analyze the parameters of PVE in the ground truth provided by the expert.
我们提出了一个数学框架，用于在存在部分容积效应（PVE）的情况下，对计算机断层扫描（CT）图像中的脑室区域脑脊液（CSF）进行分割。首先，使用高斯混合模型（GMM）拟合图像直方图。通过分析GMM，我们基于CSF以及白质和灰质组合（WGM）的分布参数找到全局阈值。使用卷积算子估计脑室边界上PVE像素的分布参数。通过分析相邻像素强度对PVE像素的贡献，利用这些参数计算边界像素的局部阈值。即使在直方图几乎为单峰的情况下，该方法也能起作用；它有助于分析专家提供的真实数据中PVE的参数。
