Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Improving the sub-cortical gm segmentation using evolutionary hierarchical region merging
Download
index.pdf
Date
2011
Author
Çiftçioğlu, Mustafa Ulaş
Metadata
Show full item record
Item Usage Stats
240
views
93
downloads
Cite This
Segmentation of sub-cortical Gray Matter (GM) structures in magnetic resonance brain images is crucial in clinic and research for many purposes such as early diagnosis of neurological diseases, guidance of surgical operations and longitudinal volumetric studies. Unfortunately, the algorithms that segment the brain into 3 tissues usually suffer from poor performance in the sub-cortical region. In order to increase the detection of sub-cortical GM structures, an evolutionary hierarchical region merging approach, abbreviated as EHRM, is proposed in this study. Through EHRM, an intensity based region merging is utilized while merging is allowed to proceed among disconnected regions. Texture information is also incorporated into the scheme to prevent the region merging between tissues with similar intensity but different texture properties. The proposed algorithm is tested on real and simulated datasets. The performance is compared with a popular segmentation algorithm, which is also intensity driven: the FAST algorithm [1] in the widely used FSL suite. EHRM is shown to make a significant improvement the detection of sub-cortical GM structures. Average improvements of 10%, 36% and 22% are achieved for caudate, putamen and thalamus respectively. The accuracy of volumetric estimations also increased for GM and WM. Performance of EHRM is robust in presence of bias field. In addition, EHRM operates in O(N) complexity. Furthermore, the algorithm proposed here is simple, because it does not incorporate spatial priors such as an atlas image or intensity priors. With these features, EHRM may become a favorable alternative to the existing brain segmentation tools.
Subject Keywords
Medical Informatics.
,
Magnetic resonance imaging.
,
Diagnostic imaging.
URI
http://etd.lib.metu.edu.tr/upload/12613413/index.pdf
https://hdl.handle.net/11511/20609
Collections
Graduate School of Informatics, Thesis
Suggestions
OpenMETU
Core
Statistical disease detection with resting state functional magnetic resonance imaging
Öztürk, Ebru; İlk Dağ, Özlem; Department of Statistics (2017)
Most of the functional magnetic resonance imaging (fMRI) data are based on a particular task. The fMRI data are obtained while the subject performs a task. Yet, it's obvious that the brain is active even when the subject is not performing a task. Resting state fMRI (R-fMRI) is a comparatively new and popular technique for assessing regional interactions when a subject is not performing a task. This study focuses on classifying subjects as healthy or diseased with the diagnosis of schizophrenia by analyzing ...
Coil sensitivity map calculation using biot-savart law at 3 tesla and parallel imaging in MRI
Esin, Yunus Emre; Alpaslan, Ferda Nur; Department of Computer Engineering (2017)
Coil spatial sensitivity map is considered as one of the most valuable data used in parallel magnetic resonance imaging (MRI) reconstruction. In this study, a novel sensitivity map extraction method is introduced for phased-array coils. Proposed technique uses Biot-Savart law with coil shape information and low-resolution phase image data to form sensitivity maps. The performance of this method has been tested in the parallel image reconstruction task using sensitivity encoding technique. In MRI, coil sensi...
Functional magnetic resonance imaging (fMRI) simulator
Arslankoz, Kamil; Gökçay, Didem; Department of Medical Informatics (2015)
Functional magnetic resonance imaging (fMRI) utilizes the change in the oxygenation of blood to predict active areas in the brain. fMRI consists of multiple low resolution whole brain images, for which, the contrast difference in corresponding voxels among all images are studied. In this study, an fMRI simulator has been developed which generates customized 4D fMRI data that can be used as a ground truth for comparing/benchmarking different fMRI analysis methods. This simulator can be also used for educatio...
CEREBRA: a 3-D visualization and processing tool for brain network extracted from fMRI data
Nasır, Barış; Yarman Vural, Fatoş Tunay; Department of Computer Engineering (2017)
In this thesis, we introduce a new tool, CEREBRA, for visualizing 3D network of human brain, extracted from the functional magnetic resonance imaging (fMRI) data. The tool aims to visualize the selected voxels as the nodes of the network and the edge weights are estimated by modeling the relationships among the voxel time series as a set of linear regression equations. This way, researchers can analyze the active brain regions/voxels and observe the interactions among them by analyzing the edge weights and ...
Convolutional neural network based brain MRI segmentation
Baydar, Bora; Akar, Gözde; Department of Electrical and Electronics Engineering (2018)
Visualization of the inner parts of human body is crucial in modern medicine and magnetic resonance imaging(MRI) is one of the widely used medical imaging methods. Manual analysis of MRIs, however, wastes the valuable time of experts. Development of an automatic segmentation method for brain MRIs can save time spent by the experts and can avoid human error factor. In this thesis, convolutional neural network (CNN) based methods are applied on brain MRI segmentation problem. The basic architectures used are ...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
M. U. Çiftçioğlu, “Improving the sub-cortical gm segmentation using evolutionary hierarchical region merging,” M.S. - Master of Science, Middle East Technical University, 2011.