Paper
15 March 2006 Generalized expectation-maximization segmentation of brain MR images
Arnaud A. Devalkeneer, Pierre A. Robe, Jacques G. Verly, Christophe L. M. Phillips
Author Affiliations +
Abstract
Manual segmentation of medical images is unpractical because it is time consuming, not reproducible, and prone to human error. It is also very difficult to take into account the 3D nature of the images. Thus, semi- or fully-automatic methods are of great interest. Current segmentation algorithms based on an Expectation- Maximization (EM) procedure present some limitations. The algorithm by Ashburner et al., 2005, does not allow multichannel inputs, e.g. two MR images of different contrast, and does not use spatial constraints between adjacent voxels, e.g. Markov random field (MRF) constraints. The solution of Van Leemput et al., 1999, employs a simplified model (mixture coefficients are not estimated and only one Gaussian is used by tissue class, with three for the image background). We have thus implemented an algorithm that combines the features of these two approaches: multichannel inputs, intensity bias correction, multi-Gaussian histogram model, and Markov random field (MRF) constraints. Our proposed method classifies tissues in three iterative main stages by way of a Generalized-EM (GEM) algorithm: (1) estimation of the Gaussian parameters modeling the histogram of the images, (2) correction of image intensity non-uniformity, and (3) modification of prior classification knowledge by MRF techniques. The goal of the GEM algorithm is to maximize the log-likelihood across the classes and voxels. Our segmentation algorithm was validated on synthetic data (with the Dice metric criterion) and real data (by a neurosurgeon) and compared to the original algorithms by Ashburner et al. and Van Leemput et al. Our combined approach leads to more robust and accurate segmentation.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Arnaud A. Devalkeneer, Pierre A. Robe, Jacques G. Verly, and Christophe L. M. Phillips "Generalized expectation-maximization segmentation of brain MR images", Proc. SPIE 6144, Medical Imaging 2006: Image Processing, 61443I (15 March 2006); https://doi.org/10.1117/12.649523
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Cited by 4 scholarly publications.
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KEYWORDS
Image segmentation

Expectation maximization algorithms

Scanning probe microscopy

Tissues

Magnetic resonance imaging

Brain

Image processing algorithms and systems

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