Exhibit Hall | Forum 6
Purpose: To develop an automated vessel wall segmentation method on T1-weighted intracranial vessel wall magnetic resonance images, with a focus on modeling the inclusion relation between the inner and outer boundaries of the vessel wall.
Methods: We propose a novel method that estimates the inner and outer vessel wall boundaries simultaneously, using a network with a single output channel resembling the level-set function height, different from the multi-channel output as in conventional multi-class and multi-label segmentation. The network is driven by a unique tiered loss that accounts for data fidelity of the lumen and vessel wall classes and regularization in the smoothness of class transition and segmentation boundaries.
Results: The proposed method achieved Dice similarity coefficients (DSC) in 2D of 0.925 ± 0.048, 0.786 ± 0.084, Hausdorff distance (HD) of 0.286 ± 0.436 mm, 0.345 ± 0.419 mm and mean surface distance (MSD) of 0.083 ± 0.037 mm and 0.103 ± 0.032 mm for the lumen and vessel wall, respectively, on a test set with 360 image slices; compared favorably to a benchmark model using multi-label setting that achieved DSC 0.924 ± 0.047, 0.794 ± 0.082, HD 0.298 ± 0.477 mm, 0.394 ± 0.431 mm, and MSD 0.087 ± 0.056 mm, 0.119 ± 0.059 mm. Most importantly, our vessel wall segmentation method achieved significant improvement in morphological integrity and feasibility compared to benchmark multi-label and polar-coordinated segmentation methods.
Conclusion: The proposed method provides a systematic approach to model the inclusion morphology and incorporate it into an optimization infrastructure. It generalizes to other applications where inclusion exists among a (sub)set of classes to be segmented. Improved feasibility in result morphology promises better support for clinical quantification and decision.
Funding Support, Disclosures, and Conflict of Interest: This work is supported in part by NIH/NHLBI R01 HL147355.