title: Improving the convergence rate in affine registration of PET and SPECT brain images using histogram equalization.
abstract: A procedure to improve the convergence rate for affine registration methods of medical brain images when the images differ greatly from the template is presented. The methodology is based on a histogram matching of the source images with respect to the reference brain template before proceeding with the affine registration. The preprocessed source brain images are spatially normalized to a template using a general affine model with 12 parameters. A sum of squared differences between the source images and the template is considered as objective function, and a Gauss-Newton optimization algorithm is used to find the minimum of the cost function. Using histogram equalization as a preprocessing step improves the convergence rate in the affine registration algorithm of brain images as we show in this work using SPECT and PET brain images.
authors.affiliation: Department of Signal Theory Networking and Communication, University of Granada, ETSIIT, 18071 Granada, Spain. dsalas@ugr.es
authors.forename: D
authors.initials: D
authors.lastname: Salas-Gonzalez
authors.forename: J M
authors.initials: JM
authors.lastname: Górriz
authors.forename: J
authors.initials: J
authors.lastname: Ramírez
authors.forename: P
authors.initials: P
authors.lastname: Padilla
authors.forename: I A
authors.initials: IA
authors.lastname: Illán
mesh_terms: D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping / Q000706:statistics & numerical data; D019295:Computational Biology; D003545:Cysteine / Q000031:analogs & derivatives; D019788:Fluorodeoxyglucose F18; D006801:Humans; D015233:Models, Statistical; D059906:Neuroimaging / Q000706:statistics & numerical data*; D015609:Organotechnetium Compounds; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data*
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C059659:technetium Tc 99m bicisate; D003545:Cysteine