Image segmentation is considered one of the essential steps in medical image analysis. Cases such as classification of tissue structures for quantitative analysis, reconstruction of anatomical volumes for visualization, and registration of multi-modality images for complementary study often require the segmentation of the brain to accomplish the task. In many clinical applications, parts of this task are performed either manually or interactively. Not only is this proces often tedious and time-consuming, it introduces additional external factors of inter- and intra-rater variability. In this paper, we present a 3D automated algorithm for segmenting the brain from various MR images. This algorithm consists of a sequence of pre-determined steps: First, an intensity window for initial separation of the brain volume from the background and non-brain structures is selected by using probability curves fitting on the intensity histogram. Next, a 3D isotropic volume is interpolated and an optimal threshold value is determined to construct a binary brain mask. The morphological and connectivity processes are then applied on this 3D mask for eliminating the non-brain structures. Finally, a surface extraction kernel is applied to extract the 3D brain surface. Preliminary results from the same subjects with different pulse sequences are compared with the manual segmentation. The automatically segmented brain volumes are compared with the manual results using the correlation coefficient and percentage overlay. Then the automatically detected surfaces are measured with the manual contouring in terms of RMS distance. The introduced automatic segmentation algorithm is effective on different sequences of MR data sets without any parameter tuning. It requires no user interaction so variability introduced by manual tracing or interactive thresholding can be eliminated. Currently, the introduced segmentation algorithm is applied in the automated inter- and intra-modality image registration. It will furthermore be used in different applications such as quantitative analysis of normal and abnormal brain tissues.
Statistical methods in the spatial, wavelet and Fourier domain were applied to two groups of subjects imaged by PET. Furthermore, simulated PET images were created to study the behaviour of these tests under restricted conditions. In particular, a rigorous statistical model in the Fourier domain was used to study general properties of group images, image enhancement and discrimination as it pertains to classification. In the spatial domain, detection of localized differences between groups is presented by applying the recent extension of the theory of Gaussian random fields to medical imaging. Finally, comparisons are made of the Fourier, spatial and wavelet domain methods for detection of localized differences between groups.
This paper consists of two parts. The first part considers the limitations imposed by statistical properties of ultrasound images. Through this analysis the minimum detectable tumor size from an ultrasound Bscan using the current state of the art is determined the second part describes an improvement to a successful tissue-characterization algorithm that adds several image processing steps to compute the tissuecharacterization features. The inclusion of such steps will enable the tissue-characterization algorithm to take advantage of visual cues similar to those that a clinician would use to differentiate various organs and segments of the image. This in turn expands the applicability of the present tissue-characterization algorithm from multivariate to multiorgan and multidisease cases.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.