A decision-theoretic generalization of on-line learning and an application to boosting
Journal of Computer and System Sciences - Special issue: 26th annual ACM symposium on the theory of computing & STOC'94, May 23–25, 1994, and second annual Europe an conference on computational learning theory (EuroCOLT'95), March 13–15, 1995
Automatic Subcortical Segmentation Using a Contextual Model
MICCAI '08 Proceedings of the 11th international conference on Medical Image Computing and Computer-Assisted Intervention - Part I
Auto-Context and Its Application to High-Level Vision Tasks and 3D Brain Image Segmentation
IEEE Transactions on Pattern Analysis and Machine Intelligence
| Hi-index | 0.00 |
In investigation of neurological diseases, accurate measurement of hippocampus is very important for differentiating inter-subject difference and subtle longitudinal change. Although many automatic segmentation methods have been developed, their performance can be limited by the poor image contrast of hippocampus in the MR images, acquired from either 1.5T or 3.0T scanner. Recently, the emergence of 7.0T scanner sheds new light on the study of hippocampus by providing much higher contrast and resolution. But the automatic segmentation algorithm for 7.0T images still lags behind the development of high-resolution imaging techniques. In this paper, we present a learning-based algorithm for segmenting hippocampi from 7.0T images, by using multi-atlases technique and auto-context models. Specifically, for each atlas (along with other aligned atlases), Auto-Context Model (ACM) is performed to iteratively construct a sequence of classifiers by integrating both image appearance and context features in the local patch. Since there exist plenty of texture information in 7.0T images, more advanced texture features are also extracted and incorporated into the ACM during the training stage. With the use of multiple atlases, multiple sequences of ACM-based classifiers will be trained, respectively in each atlas' space. Thus, in the application stage, a new image will be segmented by first applying the sequence of the learned classifiers of each atlas to it, and then fusing multiple segmentation results from multiple atlases (or multiple sequences of classifiers) by a label-fusion technique. Experimental results on the six 7.0T images with voxel size of 0.35 × 0.35 × 0.35mm3 show much better results obtained by our method than by the method using only the conventional auto-context model.