Measuring and comparing brain cortical surface area and other areal quantities

Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
NeuroImage (Impact Factor: 6.36). 03/2012; 61(4):1428-43. DOI: 10.1016/j.neuroimage.2012.03.026
Source: PubMed


Structural analysis of MRI data on the cortical surface usually focuses on cortical thickness. Cortical surface area, when considered, has been measured only over gross regions or approached indirectly via comparisons with a standard brain. Here we demonstrate that direct measurement and comparison of the surface area of the cerebral cortex at a fine scale is possible using mass conservative interpolation methods. We present a framework for analyses of the cortical surface area, as well as for any other measurement distributed across the cortex that is areal by nature. The method consists of the construction of a mesh representation of the cortex, registration to a common coordinate system and, crucially, interpolation using a pycnophylactic method. Statistical analysis of surface area is done with power-transformed data to address lognormality, and inference is done with permutation methods. We introduce the concept of facewise analysis, discuss its interpretation and potential applications.

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    • "Statistical analyses are now often conducted both using standard univariate methods and multi-voxel pattern analysis (MVPA) (Haynes and Rees, 2006; Kriegeskorte et al., 2006; Norman et al., 2006). Brain structure is often analyzed using voxel-(Ashburner, 2009) and surface-based (Winkler et al., 2012) morphometry, and gyrification indices (Schaer et al., 2008). Registration between individuals can use relatively low-dimensional warping to a template, or higher dimensional registration (Ashburner, 2007, 2009). "
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    Frontiers in Neuroinformatics 01/2015; 8:90. DOI:10.3389/fninf.2014.00090 · 3.26 Impact Factor
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    • "Not all variables in our study met all these requirements. In addition, measurements related to biological morphology, such as lengths, areas, volumes and weights, are well known to follow non-normal distributions (Winkler et al., 2012). "
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    ABSTRACT: Introduction: Recent evidence points to overlapping decreases in cortical thickness and gyrification in the frontal lobe of patients with adult-onset schizophrenia and bipolar disorder with psychotic symptoms, but it is not clear if these findings generalize to patients with a disease onset during adolescence and what may be the mechanisms underlying a decrease in gyrification. Method: This study analyzed cortical morphology using surface-based morphometry in 92 subjects (age range 11-18 years, 52 healthy controls and 40 adolescents with early-onset first-episode psychosis diagnosed with schizophrenia (n=20) or bipolar disorder with psychotic symptoms (n=20) based on a two year clinical follow up). Average lobar cortical thickness, surface area, gyrification index (GI) and sulcal width were compared between groups, and the relationship between the GI and sulcal width was assessed in the patient group. Results: Both patients groups showed decreased cortical thickness and increased sulcal width in the frontal cortex when compared to healthy controls. The schizophrenia subgroup also had increased sulcal width in all other lobes. In the frontal cortex of the combined patient group sulcal width was negatively correlated (r=-0.58, p<0.001) with the GI. Conclusions: In adolescents with schizophrenia and bipolar disorder with psychotic symptoms there is cortical thinning, decreased GI and increased sulcal width of the frontal cortex present at the time of the first psychotic episode. Decreased frontal GI is associated with the widening of the frontal sulci which may reduce sulcal surface area. These results suggest that abnormal growth (or more pronounced shrinkage during adolescence) of the frontal cortex represents a shared endophenotype for psychosis.
    Schizophrenia Research 07/2014; 158(1-3). DOI:10.1016/j.schres.2014.06.040 · 3.92 Impact Factor
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    • "Potentially, the association between V1 surface area and P100 amplitude might result from non-specific relationships between cortical surface area and EEG-amplitudes. To investigate regional specificity, we performed a whole brain analysis of local surface areal expansion/contraction, which represents an estimate of relative surface area at each vertex across the cerebral cortex (Winkler et al. 2012), while covarying for age, sex and eTIV. This analysis revealed that P100 amplitude was significantly and selectively associated with local surface areal expansion/contraction in regions within the bilateral V1 masks (n = 39; p \ 0.05, fully corrected for multiple comparisons across the cortex; Fig. 2). "
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    ABSTRACT: The extensive and increasing use of structural neuroimaging in the neurosciences rests on the assumption of an intimate relationship between structure and function in the human brain. However, few studies have examined the relationship between advanced magnetic resonance imaging (MRI) indices of cerebral structure and conventional measures of cerebral functioning in humans. Here we examined whether MRI-based morphometric measures of early visual cortex-estimated using a probabilistic anatomical mask of primary visual cortex (V1)-can predict the amplitude of the visual evoked potential (VEP), i.e., an electroencephalogram signal that primarily reflects postsynaptic potentials in early visual cortical areas. We found that left, right, and total V1 surface area positively predicted the VEP amplitude. In addition, we showed, using whole brain analysis of local surface areal expansion/contraction, that the association between VEP amplitude and surface area was highly specific for regions within bilateral V1. Together, these findings indicate a strong, selective relationship between MRI-based structural measures and functional properties of the human cerebral cortex.
    Brain Structure and Function 01/2014; 220(2). DOI:10.1007/s00429-013-0703-7 · 5.62 Impact Factor
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