Akselrod-Ballin Ayelet, Galun Meirav, Gomori Moshe John, Basri Ronen, Brandt Achi
Dept. of Computer Science and Applied Math, Weizmann Institute of Science, Rehovot, Israel.
Med Image Comput Comput Assist Interv. 2006;9(Pt 2):209-16. doi: 10.1007/11866763_26.
This study presents a novel automatic approach for the identification of anatomical brain structures in magnetic resonance images (MRI). The method combines a fast multiscale multi-channel three dimensional (3D) segmentation algorithm providing a rich feature vocabulary together with a support vector machine (SVM) based classifier. The segmentation produces a full hierarchy of segments, expressed by an irregular pyramid with only linear time complexity. The pyramid provides a rich, adaptive representation of the image, enabling detection of various anatomical structures at different scales. A key aspect of the approach is the thorough set of multiscale measures employed throughout the segmentation process which are also provided at its end for clinical analysis. These features include in particular the prior probability knowledge of anatomic structures due to the use of an MRI probabilistic atlas. An SVM classifier is trained based on this set of features to identify the brain structures. We validated the approach using a gold standard real brain MRI data set. Comparison of the results with existing algorithms displays the promise of our approach.
本研究提出了一种用于在磁共振成像(MRI)中识别脑部解剖结构的新型自动方法。该方法将一种快速多尺度多通道三维(3D)分割算法与基于支持向量机(SVM)的分类器相结合,前者可提供丰富的特征词汇表。分割产生了一个完整的分割层次结构,由一个仅具有线性时间复杂度的不规则金字塔表示。该金字塔为图像提供了丰富的自适应表示,能够在不同尺度上检测各种解剖结构。该方法的一个关键方面是在整个分割过程中采用的一整套多尺度测量方法,这些测量方法在分割结束时也会提供用于临床分析。这些特征尤其包括由于使用MRI概率图谱而获得的解剖结构的先验概率知识。基于这组特征训练一个SVM分类器来识别脑部结构。我们使用一个金标准真实脑部MRI数据集对该方法进行了验证。将结果与现有算法进行比较显示了我们方法的前景。