Bias between MNI and Talairach coordinates analyzed using the ICBM-152 brain template

• Published in: Human brain mapping Vol. 28; no. 11; pp. 1194 - 1205
• Main Authors: Lancaster, Jack L., Tordesillas-Gutiérrez, Diana, Martinez, Michael, Salinas, Felipe, Evans, Alan, Zilles, Karl, Mazziotta, John C., Fox, Peter T.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.11.2007; Wiley-Liss
• Subjects: Algorithms; Bias; Biological and medical sciences; Brain - anatomy & histology; Brain - pathology; Brain Mapping - methods; Electrodiagnosis. Electric activity recording; Fourier Analysis; Humans; ICBM-152 template; Image Processing, Computer-Assisted - methods; Imaging, Three-Dimensional; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Imaging - methods; Medical sciences; MNI coordinates; MNI-305 template; Models, Anatomic; Nervous system; Nervous system (semeiology, syndromes); Nervous system as a whole; Neurology; Pattern Recognition, Automated; Radiodiagnosis. Nmr imagery. Nmr spectrometry; reference frame bias; Reference Values; Software; spatial normalization; Stereotaxic Techniques; Talairach coordinates; Talairach coordinates; spatial normalization; Nervous system diseases; ICBM-152 template; Radiodiagnosis; MNI coordinates; MNI-305 template; Bias; Central nervous system; reference frame bias; Encephalon
• ISSN: 1065-9471; 1097-0193; 1097-0193
• DOI: 10.1002/hbm.20345

MNI coordinates determined using SPM2 and FSL/FLIRT with the ICBM‐152 template were compared to Talairach coordinates determined using a landmark‐based Talairach registration method (TAL). Analysis revealed a clear‐cut bias in reference frames (origin, orientation) and scaling (brain size). Accordingly, ICBM‐152 fitted brains were consistently larger, oriented more nose down, and translated slightly down relative to TAL fitted brains. Whole brain analysis of MNI/Talairach coordinate disparity revealed an ellipsoidal pattern with disparity ranging from zero at a point deep within the left hemisphere to greater than 1‐cm for some anterior brain areas. MNI/Talairach coordinate disparity was generally less for brains fitted using FSL. The mni2tal transform generally reduced MNI/Talairach coordinate disparity for inferior brain areas but increased disparity for anterior, posterior, and superior areas. Coordinate disparity patterns differed for brain templates (MNI‐305, ICBM‐152) using the same fitting method (FSL/FLIRT) and for different fitting methods (SPM2, FSL/FLIRT) using the same template (ICBM‐152). An MNI‐to‐Talairach (MTT) transform to correct for bias between MNI and Talairach coordinates was formulated using a best‐fit analysis in one hundred high‐resolution 3‐D MR brain images. MTT transforms optimized for SPM2 and FSL were shown to reduced group mean MNI/Talairach coordinate disparity from a 5‐13 mm to 1‐2 mm for both deep and superficial brain sites. MTT transforms provide a validated means to convert MNI coordinates to Talairach compatible coordinates for studies using either SPM2 or FSL/FLIRT with the ICBM‐152 template. Hum Brain Mapp 2007. © 2007 Wiley‐Liss, Inc.