Investigating the impact of supervoxel segmentation for unsupervised abnormal brain asymmetry detection

Author(s)

Martins, Samuel B. ^{[1, 2, 3]} ; Telea, Alexandru C. ^[4] ; Falcao, Alexandre X. ^[1]

Affiliation

^[1] Univ Estadual Campinas, Lab Image Data Sci LIDS, Inst Comp, Campinas, SP - Brazil

^[2] Univ Groningen, Bernoulli Inst, Groningen - Netherlands

^[3] Fed Inst Sao Paulo, Campinas - Brazil

^[4] Univ Utrecht, Dept Informat & Comp Sci, Utrecht - Netherlands

• Document type: Journal article
• Source: Computerized Medical Imaging and Graphics; v. 85, OCT 2020.
• Web of Science Citations: 0

Abstract

Several brain disorders are associated with abnormal brain asymmetries (asymmetric anomalies). Several computer-based methods aim to detect such anomalies automatically. Recent advances in this area use automatic unsupervised techniques that extract pairs of symmetric supervoxels in the hemispheres, model normal brain asymmetries for each pair from healthy subjects, and treat outliers as anomalies. Yet, there is no deep understanding of the impact of the supervoxel segmentation quality for abnormal asymmetry detection, especially for small anomalies, nor of the added value of using a specialized model for each supervoxel pair instead of a single global appearance model. We aim to answer these questions by a detailed evaluation of different scenarios for supervoxel segmentation and classification for detecting abnormal brain asymmetries. Experimental results on 3D MR-Tl brain images of stroke patients confirm the importance of high-quality supervoxels fit anomalies and the use of a specific classifier for each supervoxel. Next, we present a refinement of the detection method that reduces the number of false-positive supervoxels, thereby making the detection method easier to use for visual inspection and analysis of the found anomalies. (AU)

• FAPESP's process: 14/12236-1 - AnImaLS: Annotation of Images in Large Scale: what can machines and specialists learn from interaction?
• Grantee: Alexandre Xavier Falcão
• Support Opportunities: Research Projects - Thematic Grants