Shin-Ting Wu, A. C. Valente, L. Watanabe, C. Yasuda, A. Coan, F. Cendes
{"title":"Pre-alignment for Co-registration in Native Space","authors":"Shin-Ting Wu, A. C. Valente, L. Watanabe, C. Yasuda, A. Coan, F. Cendes","doi":"10.1109/SIBGRAPI.2014.40","DOIUrl":null,"url":null,"abstract":"For nonlesional patients, the correct localization of the epileptogenic foci in native space remains a great challenge. Non-invasive functional PET images that provide information about cerebral activities may reveal the origin of seizure activity, but without precise anatomical detail. Co-registration of the functional images with MR images on the basis of maximization of mutual information (MMI) has shown to be very promising in improving presurgical evaluation. Nevertheless, a mutual information (MI) function is non-convex and the convergence of an algorithm to its optimum is guaranteed only if the initial estimate lies in its convex vicinity. We present in this paper a generally applicable method that pre-aligns the DICOM images such that their relative position becomes close to an optimum. The key to our solution is a robust user-guided interactive procedure to extract valid voxels, for both the centroid estimation and the registration. Aiming at comparative analysis, we introduce a numerical condition to quantify registration errors. The results are acceptable when we consider the intrinsic problems of the MMI-based registration algorithm we implemented.","PeriodicalId":146229,"journal":{"name":"2014 27th SIBGRAPI Conference on Graphics, Patterns and Images","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2014-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2014 27th SIBGRAPI Conference on Graphics, Patterns and Images","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/SIBGRAPI.2014.40","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 5
Abstract
For nonlesional patients, the correct localization of the epileptogenic foci in native space remains a great challenge. Non-invasive functional PET images that provide information about cerebral activities may reveal the origin of seizure activity, but without precise anatomical detail. Co-registration of the functional images with MR images on the basis of maximization of mutual information (MMI) has shown to be very promising in improving presurgical evaluation. Nevertheless, a mutual information (MI) function is non-convex and the convergence of an algorithm to its optimum is guaranteed only if the initial estimate lies in its convex vicinity. We present in this paper a generally applicable method that pre-aligns the DICOM images such that their relative position becomes close to an optimum. The key to our solution is a robust user-guided interactive procedure to extract valid voxels, for both the centroid estimation and the registration. Aiming at comparative analysis, we introduce a numerical condition to quantify registration errors. The results are acceptable when we consider the intrinsic problems of the MMI-based registration algorithm we implemented.