title: Measures for the evaluation of bias field removal procedures in MRI and the design of wavelets for suppression of RF inhomogeneities.
abstract: RF inhomogeneities are illumination artifacts in MR images which manifest as a multiplicative bias field. To measure the quality of an MR image with respect to RF inhomogeneities, existing multi-valued criteria are in use. Here we propose a useful conversion of these multi-valued criteria into a single measure of quality which simplifies image quality evaluation and comparison. Next, to remove such a bias field, a novel wavelet based approach is employed, that extends a previous 1D wavelet design methodology to a 2D setting. This method is found to perform well on images with strong small details. The results for brain MR images are subject to improvement, however our results hint to a future scenario for improved image quality.
authors.affiliation: Department of Mathematics, Maastricht University, Maastricht, The Netherlands. joel.karel@math.unimaas.nl
authors.forename: J M H
authors.initials: JM
authors.lastname: Karel
authors.forename: K
authors.initials: K
authors.lastname: Fischer
authors.forename: R L
authors.initials: RL
authors.lastname: Westra
authors.forename: R L M
authors.initials: RL
authors.lastname: Peeters
mesh_terms: D000465:Algorithms; D001921:Brain / Q000473:pathology*; D003198:Computer Simulation; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D015233:Models, Statistical; D019047:Phantoms, Imaging; D011786:Quality Control; D011846:Radio Waves; D013382:Subtraction Technique