title: Retrospective correction of the heel effect in hand radiographs.
abstract: A method for the retrospective correction of intensity inhomogeneities induced by the heel effect in digital radiographs is presented. The method is based on a mathematical model for the heel effect derived from the acquisition geometry. The model parameters are estimated by fitting the model to the image intensity data in the background or direct exposure area only where the heel effect is directly measurable, while the correction is then applied to the whole image. The method iterates between background segmentation and heel effect correction until convergence. We illustrate the performance of the method on flat field and phantom images and demonstrate its robustness on a database of 137 diagnostic hand radiographs.
authors.affiliation: Katholieke Universiteit Leuven, Faculties of Medicine and Engineering, Medical Image Computing (Radiology - ESAT/PSI), University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium. gert.behiels@uz.kuleuven.ac.be
authors.forename: Gert
authors.initials: G
authors.lastname: Behiels
authors.forename: Frederik
authors.initials: F
authors.lastname: Maes
authors.forename: Dirk
authors.initials: D
authors.lastname: Vandermeulen
authors.forename: Paul
authors.initials: P
authors.lastname: Suetens
mesh_terms: D000465:Algorithms; D016477:Artifacts; D016208:Databases, Factual; D006225:Hand / Q000000981:diagnostic imaging*; D006801:Humans; D008954:Models, Biological; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity