title: Analysis of macular OCT images using deformable registration.
abstract: Optical coherence tomography (OCT) of the macula has become increasingly important in the investigation of retinal pathology. However, deformable image registration, which is used for aligning subjects for pairwise comparisons, population averaging, and atlas label transfer, has not been well-developed and demonstrated on OCT images. In this paper, we present a deformable image registration approach designed specifically for macular OCT images. The approach begins with an initial translation to align the fovea of each subject, followed by a linear rescaling to align the top and bottom retinal boundaries. Finally, the layers within the retina are aligned by a deformable registration using one-dimensional radial basis functions. The algorithm was validated using manual delineations of retinal layers in OCT images from a cohort consisting of healthy controls and patients diagnosed with multiple sclerosis (MS). We show that the algorithm overcomes the shortcomings of existing generic registration methods, which cannot be readily applied to OCT images. A successful deformable image registration algorithm for macular OCT opens up a variety of population based analysis techniques that are regularly used in other imaging modalities, such as spatial normalization, statistical atlas creation, and voxel based morphometry. Examples of these applications are provided to demonstrate the potential benefits such techniques can have on our understanding of retinal disease. In particular, included is a pilot study of localized volumetric changes between healthy controls and MS patients using the proposed registration algorithm.
authors: Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD, 21218, USA ; Translational Neuroradiology Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA.
authors: Min
authors: M
authors: Chen
authors: Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD, 21218, USA.
authors: Andrew
authors: A
authors: Lang
authors: Wilmer Eye Institute, The Johns Hopkins School of Medicine, Baltimore, MD 21287, USA.
authors: Howard S
authors: HS
authors: Ying
authors: Department of Neurology, The Johns Hopkins School of Medicine, Baltimore, MD 21287, USA.
authors: Peter A
authors: PA
authors: Calabresi
authors: Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD, 21218, USA.
authors: Jerry L
authors: JL
authors: Prince
authors: Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD, 21218, USA.
authors: Aaron
authors: A
authors: Carass
keywords: (100.0100) Image processing; (170.4470) Ophthalmology; (170.4500) Optical coherence tomography