Probabilistic intra-retinal layer segmentation in 3-D OCT images using global shape regularization

With the introduction of spectral-domain optical coherence tomography (OCT), resulting in a significant increase in acquisition speed, the fast and accurate segmentation of 3-D OCT scans has become evermore important. This paper presents a novel probabilistic approach, that models the appearance of retinal layers as well as the global shape variations of layer boundaries. Given an OCT scan, the full   posterior distribution over segmentations is approximately inferred using a variational method enabling efficient probabilistic inference in terms of computationally tractable model components: Segmenting a full 3-D volume takes around a minute. Accurate segmentations demonstrate the benefit of using global shape regularization: We segmented 35 fovea-centered 3-D volumes with an average unsigned error of 2.46±0.22μm as well as 80 normal and 66 glaucomatous 2-D circular scans with errors of 2.92±0.5μm and 4.09±0.98μm respectively. Furthermore, we utilized the inferred posterior distribution to rate the quality of the segmentation, point out potentially erroneous regions and discriminate normal from pathological scans. No pre- or postprocessing was required and we used the same set of parameters for all data sets, underlining the robustness and out-of-the-box nature of our approach.

Figure optionsDownload high-quality image (169 K)Download as PowerPoint slideHighlights
• First approach for the segmentation of retinal cell layers that incorporates global shape information.
• Outperforms all previous approaches that rely on local or no shape information.
• Inferring a distribution over segmentations allows pathology detection and the assessment of the segmentation quality.
• Inherent sparsity in the model enables segmentation of a 3-D volume in less than a minute.