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  • 33425820

    Final published version, 1.41 MB, PDF document

DOI

Optical coherence tomography (OCT) yields high-resolution, three-dimensional images of the retina. A better understanding of retinal nerve fiber bundle (RNFB) trajectories in combination with visual field data may be used for future diagnosis and monitoring of glaucoma. However, manual tracing of these bundles is a tedious task. In this work, we present an automatic technique to estimate the orientation of RNFBs from volumetric OCT scans. Our method consists of several steps, starting from automatic segmentation of the RNFL. Then, a stack of en face images around the posterior nerve fiber layer interface was extracted. The image showing the best visibility of RNFB trajectories was selected for further processing. After denoising the selected en face image, a semblance structure-oriented filter was applied to probe the strength of local linear structure in a discrete set of orientations creating an orientation space. Gaussian filtering along the orientation axis in this space is used to find the dominant orientation. Next, a confidence map was created to supplement the estimated orientation. This confidence map was used as pixel weight in normalized convolution to regularize the semblance filter response after which a new orientation estimate can be obtained. Finally, after several iterations an orientation field corresponding to the strongest local orientation was obtained. The RNFB orientations of six macular scans from three subjects were estimated. For all scans, visual inspection shows a good agreement between the estimated orientation fields and the RNFB trajectories in the en face images. Additionally, a good correlation between the orientation fields of two scans of the same subject was observed. Our method was also applied to a larger field of view around the macula. Manual tracing of the RNFB trajectories shows a good agreement with the automatically obtained streamlines obtained by fiber tracking.

Original languageEnglish
Title of host publicationMedical Imaging 2017
Subtitle of host publicationImage Processing
EditorsMartin A. Styner, Elsa D. Angelini
Place of PublicationBellingham, WA
PublisherSPIE
Pages1-7
Number of pages7
ISBN (Electronic)9781510607118
DOIs
Publication statusPublished - 2017
EventMedical Imaging 2017: Image Processing - Orlando, United States
Duration: 12 Feb 201714 Feb 2017

Publication series

NameProceedings of SPIE
Volume10133
ISSN (Electronic)0277-786X

Conference

ConferenceMedical Imaging 2017: Image Processing
CountryUnited States
CityOrlando
Period12/02/1714/02/17

    Research areas

  • Normalized convolution, OCT, Retinal nerve fiber bundle, Semblance, Steerable filter

ID: 33425820