3-D segmentation and volume estimation of radiologic images by a novel, feature driven, region growing technique

Simple item page
dc.contributor.advisorde Figueiredo, Rui J. P.en_US
dc.creatorAgris, Jacob Martinen_US
dc.date.accessioned2009-06-04T00:30:59Zen_US
dc.date.available2009-06-04T00:30:59Zen_US
dc.date.issued1992en_US
dc.description.abstractMagnetic Resonance (MR) imaging is a 3-D, multi-slice, radiological technique that acquires multiple intensities corresponding to each voxel. The transverse relaxation time, T$\sb1$, and the axial relaxation time, T$\sb2$, are two commonly obtained intensities that tend to be orthogonal. Automated segmentation of 3-D regions is very difficult because some borders may be delineated only in T$\sb1$ images, while others are delineated only in T$\sb2$ images. Classical segmentation techniques based on either global histogram segmentation or local edge detection often fail due to the non-unique and random nature of MR intensities. A 3-D, neighborhood based, segmentation method was developed based on both spatial and intensity criteria. The spatial criterion requires that only voxels connected by an edge or face to a voxel known to be in the region be considered for inclusion. Therefore, the region "grows" outward from an initial voxel. An intensity criterion that tries to balance local and global properties must also be satisfied. It determines the vector distance between the intensity of the voxel in question and a characteristic intensity for the neighboring voxels known to be in the region. Voxel intensities within a 95% confidence interval of the characteristic intensity are considered part of the region. The kernel size used to determine the characteristic intensity determines the balance between global and local properties. The segmentation terminates when no additional voxels satisfy both spatial and error criteria. Some regions, such as the brain compartments, are highly convoluted, resulting in a large number of border voxels containing a mixture of adjoining tissues. A sub-voxel estimate of the fractional composition is necessary for accurate quantification. A least-squares estimator was derived for the fractional composition of each voxel. Additionally, a maximum likelihood estimator was derived to globally estimate the fraction for all mixture voxels. This estimator is a minimum variance estimator in contrast to the least-squares estimator. The estimation methods in conjunction with the 3-D, neighborhood based, segmentation method resulted in an automated, highly accurate, quantification technique shown to be successful even for the brain compartments. Widespread applicability of these methods was further demonstrated by segmentation of kidneys in CT images.en_US
dc.format.extent194 p.en_US
dc.format.mimetypeapplication/pdfen_US
dc.identifier.callnoThesis E.E. 1992 Agrisen_US
dc.identifier.citationAgris, Jacob Martin. "3-D segmentation and volume estimation of radiologic images by a novel, feature driven, region growing technique." (1992) Diss., Rice University. <a href="https://hdl.handle.net/1911/16544">https://hdl.handle.net/1911/16544</a>.en_US
dc.identifier.urihttps://hdl.handle.net/1911/16544en_US
dc.language.isoengen_US
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.en_US
dc.subjectElectronicsen_US
dc.subjectElectrical engineeringen_US
dc.subjectBiomedical engineeringen_US
dc.subjectRadiologyen_US
dc.title3-D segmentation and volume estimation of radiologic images by a novel, feature driven, region growing techniqueen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentElectrical Engineeringen_US
thesis.degree.disciplineEngineeringen_US
thesis.degree.grantorRice Universityen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophyen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
9234395.PDF
Size:
6.33 MB
Format:
Adobe Portable Document Format
Download
Collections
Rice University Theses and Dissertations
ECE Theses and Dissertations