PURPOSE: To evaluate the effects of gradient nonlinearity correction and intensity nonuniformity correction on longitudinal (two-year) changes in global and regional brain volumes. MATERIALS AND METHODS: A total of 208 subjects (70 females and 138 males, age range = 38.1-83.0 years) were included in this study. Each subject was scanned twice, at an interval of approximately two years (range = 1.5-2.3 years). Three-dimensional fast spoiled-gradient recalled acquisition in the steady state (3D-FSPGR) images corrected for gradient nonlinearity and/or intensity nonuniformity were compared with uncorrected 3D-FSPGR images with use of structural image evaluation using normalization of atrophy 2.6 (SIENA). RESULTS: The mean absolute deviations of percentage brain volume change (PBVC) values in the gradient nonlinearity +/- intensity nonuniformity corrected images were significantly less than that in the uncorrected images, and the difference in the mean absolute deviation of PBVC was the most significant between the uncorrected images and the images corrected for both gradient nonlinearity and intensity nonuniformity. Voxel-wise comparisons showed large significant differences between the uncorrected images and the corrected images. CONCLUSION: Correction for gradient nonlinearity and intensity nonuniformity reduces the variance of measured longitudinal changes in brain volumes and will improve accuracy for detecting subtle brain changes. 2010 Wiley-Liss, Inc.
PURPOSE: To evaluate the effects of gradient nonlinearity correction and intensity nonuniformity correction on longitudinal (two-year) changes in global and regional brain volumes. MATERIALS AND METHODS: A total of 208 subjects (70 females and 138 males, age range = 38.1-83.0 years) were included in this study. Each subject was scanned twice, at an interval of approximately two years (range = 1.5-2.3 years). Three-dimensional fast spoiled-gradient recalled acquisition in the steady state (3D-FSPGR) images corrected for gradient nonlinearity and/or intensity nonuniformity were compared with uncorrected 3D-FSPGR images with use of structural image evaluation using normalization of atrophy 2.6 (SIENA). RESULTS: The mean absolute deviations of percentage brain volume change (PBVC) values in the gradient nonlinearity +/- intensity nonuniformity corrected images were significantly less than that in the uncorrected images, and the difference in the mean absolute deviation of PBVC was the most significant between the uncorrected images and the images corrected for both gradient nonlinearity and intensity nonuniformity. Voxel-wise comparisons showed large significant differences between the uncorrected images and the corrected images. CONCLUSION: Correction for gradient nonlinearity and intensity nonuniformity reduces the variance of measured longitudinal changes in brain volumes and will improve accuracy for detecting subtle brain changes. 2010 Wiley-Liss, Inc.
Authors: François De Guio; Eric Jouvent; Geert Jan Biessels; Sandra E Black; Carol Brayne; Christopher Chen; Charlotte Cordonnier; Frank-Eric De Leeuw; Martin Dichgans; Fergus Doubal; Marco Duering; Carole Dufouil; Emrah Duzel; Franz Fazekas; Vladimir Hachinski; M Arfan Ikram; Jennifer Linn; Paul M Matthews; Bernard Mazoyer; Vincent Mok; Bo Norrving; John T O'Brien; Leonardo Pantoni; Stefan Ropele; Perminder Sachdev; Reinhold Schmidt; Sudha Seshadri; Eric E Smith; Luciano A Sposato; Blossom Stephan; Richard H Swartz; Christophe Tzourio; Mark van Buchem; Aad van der Lugt; Robert van Oostenbrugge; Meike W Vernooij; Anand Viswanathan; David Werring; Frank Wollenweber; Joanna M Wardlaw; Hugues Chabriat Journal: J Cereb Blood Flow Metab Date: 2016-05-11 Impact factor: 6.200
Authors: Andrew D Goodman; Janel K Fedler; Jon Yankey; Elizabeth A Klingner; Dixie J Ecklund; Christopher V Goebel; Robert A Bermel; Marianne Chase; Christopher S Coffey; Eric C Klawiter; Robert T Naismith; Robert J Fox Journal: Ann Clin Transl Neurol Date: 2021-01-18 Impact factor: 4.511
Authors: H Vrenken; M Jenkinson; M A Horsfield; M Battaglini; R A van Schijndel; E Rostrup; J J G Geurts; E Fisher; A Zijdenbos; J Ashburner; D H Miller; M Filippi; F Fazekas; M Rovaris; A Rovira; F Barkhof; N de Stefano Journal: J Neurol Date: 2012-12-21 Impact factor: 4.849