title: Structural Functional Associations of the Orbit in Thyroid Eye Disease: Kalman Filters to Track Extraocular Rectal Muscles.
abstract: Pathologies of the optic nerve and orbit impact millions of Americans and quantitative assessment of the orbital structures on 3-D imaging would provide objective markers to enhance diagnostic accuracy, improve timely intervention and eventually preserve visual function. Recent studies have shown that the multi-atlas methodology is suitable for identifying orbital structures, but challenges arise in the identification of the individual extraocular rectus muscles that control eye movement. This is increasingly problematic in diseased eyes, where these muscles often appear to fuse at the back of the orbit (at the resolution of clinical computed tomography imaging) due to inflammation or crowding. We propose the use of Kalman filters to track the muscles in three-dimensions to refine multi-atlas segmentation and resolve ambiguity due to imaging resolution, noise, and artifacts. The purpose of our study is to investigate a method of automatically generating orbital metrics from CT imaging and demonstrate the utility of the approach by correlating structural metrics of the eye orbit with clinical data and visual function measures in subjects with thyroid eye disease. The pilot study demonstrates that automatically calculated orbital metrics are strongly correlated with several clinical characteristics. Moreover, the superior, inferior, medial and lateral rectus muscles obtained using Kalman filters are each correlated with different categories of functional deficit. These findings serve as foundation for further investigation in the use of CT imaging in the study, analysis and diagnosis of ocular diseases, specifically thyroid eye disease.
authors.affiliation: Computer Science, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN USA 37235.
authors.forename: Shikha
authors.initials: S
authors.lastname: Chaganti
authors.affiliation: Electrical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN USA 37235.
authors.forename: Katrina
authors.initials: K
authors.lastname: Nelson
authors.affiliation: Vanderbilt Eye Institute, Vanderbilt University School of Medicine, 2311 Pierce Avenue, Nashville, TN USA 37232.
authors.forename: Kevin
authors.initials: K
authors.lastname: Mundy
authors.affiliation: Electrical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN USA 37235.
authors.forename: Yifu
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Electrical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN USA 37235.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Harrigan
authors.affiliation: Electrical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN USA 37235.
authors.forename: Steve
authors.initials: S
authors.lastname: Damon
authors.affiliation: Department of Biomedical Informatics, Vanderbilt University School of Medicine, 2525 West End Avenue Nashville, TN USA 37203.
authors.forename: Daniel
authors.initials: D
authors.lastname: Fabbri
authors.affiliation: Vanderbilt Eye Institute, Vanderbilt University School of Medicine, 2311 Pierce Avenue, Nashville, TN USA 37232.
authors.forename: Louise
authors.initials: L
authors.lastname: Mawn
authors.affiliation: Computer Science, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN USA 37235; Electrical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN USA 37235.
authors.forename: Bennett
authors.initials: B
authors.lastname: Landman
keywords: Computed Tomography; Kalman filters; Multi-Atlas Segmentation; Thyroid Eye Disease