title: Proof of principle: Transformation approach alters caudate nucleus volume and structure-function associations.
abstract: Brain magnetic resonance image (MRI) registration alters structure orientation, size, and/or shape. To determine whether linear registration methods (image transformation to 6, 9, and 12° of freedom) alter structural volume and cognitive associations, we examined transformation alterations to the caudate nucleus within individuals diagnosed with Parkinson's disease (PD) and demographically matched non-PD peers. Volumes from native and six were expected be significantly different from 9 and 12° of freedom methods. Caudate nucleus volumes were expected to be associated with measures of processing speed and mental flexibility, but the strength of the association based on transformation approach was unknown. MRI brain scans from individuals with Parkinson's disease (n = 40) and age-matched controls (n = 40) were transformed using 6, 9, and 12° of freedom to an average brain template. Correlations controlling for total intracranial volume assessed expected structural-behavioral associations. Volumetric: Raw 9 and 12° transformed volumes were significantly larger than native and 6° volumes. Only 9 and 12° volumes revealed group differences with PD less than controls. Intracranial volume considerations were essential for native and 6° between group comparisons. Structural-Behavioral: The 9 and 12° caudate nucleus volume transformations revealed the expected brain-behavioral associations. Linear registration techniques alter volumetric and cognitive-structure associations. The study highlights the need to communicate transformation approach and group intracranial volume considerations.
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, 1225 Center Drive, Gainesville, FL, 32611, USA.
authors.forename: Nadine A
authors.initials: NA
authors.lastname: Schwab
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, 1225 Center Drive, Gainesville, FL, 32611, USA.
authors.forename: Jared J
authors.initials: JJ
authors.lastname: Tanner
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, 1225 Center Drive, Gainesville, FL, 32611, USA.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Nguyen
authors.affiliation: Department of Radiology, North Florida/South Georgia Veteran Administration, University of Florida, 1601 SW Archer Rd., Gainesville, FL, 32608, USA.
authors.forename: Ilona M
authors.initials: IM
authors.lastname: Schmalfuss
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, 1225 Center Drive, Gainesville, FL, 32611, USA.|Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, 3450 Hull Rd., Gainesville, FL, 32607, USA.
authors.forename: Dawn
authors.initials: D
authors.lastname: Bowers
authors.affiliation: Department of Neurology, Center for Movement Disorders and Neurorestoration, University of Florida, 3450 Hull Rd., Gainesville, FL, 32607, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Okun
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, 1225 Center Drive, Gainesville, FL, 32611, USA. cep23@phhp.ufl.edu.|Clinical and Health Psychology, University of Florida, 101 S. Newell Drive, PO Box 100165, Gainesville, FL, 32610, USA. cep23@phhp.ufl.edu.
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Price
mesh_terms: D000368:Aged; D002421:Caudate Nucleus / Q000473:pathology*; D003071:Cognition; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009929:Organ Size; D010300:Parkinson Disease / Q000473:pathology* / Q000523:psychology*
keywords: Caudate nucleus; Degrees of freedom; Intracranial volume; Linear image registration; Parkinson’s disease; Template