Effect of slice orientation on reproducibility of fMRI motor activation at 3 Tesla

Gustard, S.; Fadili, Jalal M.; Williams, Emma; Hall, Laurance D.; Carpenter, T. Adrian; Brett, Matthew; Bullmore, Edward T.

doi:10.1016/s0730-725x(01)00399-x

Cited by 18 publications

(12 citation statements)

References 29 publications

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“…Slice-orientation, as reported by Gustard et al (2001), had a non-significant impact on the reproducibility of the fMRI signal when isotropic voxels and a simple motor paradigm were used. Spatial normalisation was shown to have a significant effect on the reproducibility of visual activation by some (Swallow et al, 2003), but not others (Miki et al, 2000).…”

Section: Introductionmentioning

confidence: 89%

Motion or activity: their role in intra- and inter-subject variation in fMRI

Lund¹,

Nørgaard²,

Rostrup³

et al. 2005

NeuroImage

211

157

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Functional MRI (fMRI) carries the potential for non-invasive measurements of brain activity. Typically what are referred to as activation images are actually thresholded statistical parametric maps. These maps possess large inter-session variability. This is especially problematic when applying fMRI to pre-surgical planning because of a higher requirement for intra-subject precision. The purpose of this study was to investigate the impact of residual movement artefacts on intra-subject and intersubject variability in the observed fMRI activation. Ten subjects were examined using three different word-generation tasks. Two of the subjects were examined 10 times on 10 different days using the same paradigms. We systematically investigated one approach of correcting for residual movement effects: the inclusion of regressors describing movement-related effects in the design matrix of a General Linear Model (GLM). The data were analysed with and without modeling the residual movement artefacts and the impact on inter-session variance was assessed using F-contrasts. Inclusion of motion parameters in the analysis significantly reduced both the intrasubject as well as the inter-subject-variance.

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Section: Introductionmentioning

confidence: 89%

Motion or activity: their role in intra- and inter-subject variation in fMRI

Lund¹,

Nørgaard²,

Rostrup³

et al. 2005

NeuroImage

211

157

View full text Add to dashboard Cite

show abstract

“…data (Gustard et al, 2001). This model overcomes the binormal assumption of the classical parametric methods and can be generalised to any statistical score (Genovese, Noll, & Eddy, 1997); it is directly applicable in our context using either the t or the F SPMs.…”

Section: Structural Image the Image Is In Neurological Convention (Lmentioning

confidence: 97%

“…The algorithm provides us with the mixing proportion (the estimated proportion of activated voxels) and effect size which best fit the data. These were estimated using a maximum likelihood procedure (Gustard et al, 2001).…”

Section: Structural Image the Image Is In Neurological Convention (Lmentioning

confidence: 99%

Do Semantic Categories Activate Distinct Cortical Regions? Evidence for a Distributed Neural Semantic System

Tyler

Bright

Dick

et al. 2003

Cognitive Neuropsychology

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A key issue in cognitive neuroscience concerns the neural representation of conceptual knowledge. Currently, debate focuses around the issue of whether there are neural regions specialised for the processing of specific semantic attributes or categories, or whether concepts are represented in an undifferentiated neural system. Neuropsychological studies of patients with selective semantic deficits and previous neuroimaging studies do not unequivocally support either account. We carried out a PET study to determine whether there is any regional specialisation for the processing of concepts from different semantic categories using picture stimuli and a semantic categorisation task. We found robust activation of a large semantic network extending from left inferior frontal cortex into the inferior temporal lobe and including occipital cortex and the fusiform gyrus. The only category effect that we found was additional activation for animals in the right occipital cortex, which we interpret as being due to the extra visual processing demands required in order to differentiate one animal from another. We also carried out analyses in specific cortical regions that have been claimed to be preferentially activated for various categories, but found no evidence of any differential activation as a function of category. We interpret these data within the framework of cognitive accounts in which conceptual knowledge is represented within a nondifferentiated distributed system.

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“…The optimization of slice orientation in fMRI studies has not received a lot of attention in the literature, although one study has suggested that oblique axial slices yield the best signal detection accuracy for a motor cortex experiment and coronal slices yield the worst (Gustard et al, 2001). The spatial dimensions of the human brain in the Talairach atlas (Talairach and Tournoux, 1988) (omitting the cerebellum) are 105 mm (I/S), 165 mm (A/P), and 123 mm (R/ L).…”

Section: Introductionmentioning

confidence: 99%

High spatial resolution increases the specificity of block-design BOLD fMRI studies of overt vowel production

Soltysik

Hyde

2008

NeuroImage

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Functional MRI (fMRI) studies of tasks involving orofacial motion, such as speech, are prone to problems related to motion-induced magnetic field variations. Orofacial motion perturbs the static magnetic field, leading to signal changes that correlate with the task and corrupt activation maps with false positives or signal loss. These motion-induced signal changes represent a contraindication for the implementation of fMRI to study the neurophysiology of orofacial motion. An fMRI experiment of a structured, non-semantic vowel production task was performed using four different voxel volumes and three different slice orientations in an attempt to find a set of acquisition parameters leading to activation maps with maximum specificity. Results indicate that the use of small voxel volumes (2×2×3 mm 3 ) yielded a significantly higher percentage of true positive activation compared to the use of larger voxel volumes. Slice orientation did not have as great an impact as spatial resolution, although coronal slices appeared superior at high spatial resolutions. Furthermore, it was found that combining the strategy of high spatial resolution with an optimum task duration and postprocessing methods for separating true and false positives greatly improved the specificity of singlesubject, block-design fMRI studies of structured, overt vowel production.

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Effect of slice orientation on reproducibility of fMRI motor activation at 3 Tesla

Cited by 18 publications

References 29 publications

Motion or activity: their role in intra- and inter-subject variation in fMRI

Motion or activity: their role in intra- and inter-subject variation in fMRI

Do Semantic Categories Activate Distinct Cortical Regions? Evidence for a Distributed Neural Semantic System

High spatial resolution increases the specificity of block-design BOLD fMRI studies of overt vowel production

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