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Abstract #3260

An a Contrario Approach for the Detection of Activated Brain Areas in FMRI

Camille Maumet1, Pierre Maurel1, Jean-Christophe Ferr1, 2, Christian Barillot1

1Visages Project-team / U746, University of Rennes 1, INSERM, CNRS, Inria, RENNES, Brittany, France; 2Department of Neuroradiology, CHU Rennes, Rennes, Brittany, France

In this paper we propose an a contrario approach for the detection of activated brain areas in BOLD functional MRI data. The method focuses on subject-specific activations. Comparisons with the standard massively univariate general linear model are provided using Receiver-Operating-Characteristics curves for two different ground truths. The data used for validation include 12 subjects, scanned 3 times for a hand-motor paradigm. Overall, the proposed a contrario approach displayed better spatially defined activation with a more interesting trade-off between sensitivity and specificity by comparison to the standard massively univariate GLM.

Keywords

ability abnormalities account activated activation activations active activity adapted assuming atlas audience avoided basal better binomial block bold brain built challenging characteristics clearly compensation computer counted criterion cross curve curves define defined delineated delineations detect detection detections discovery displayed displays distribution doctors expected false final formulation front functional general getting global grid grids ground hand healthy improvement inactive independence individual initial issue jean justifies kernel lack linear local makes manually massively medical moreover motor neat neighborhood null open operating outperformed overall paper paradigm parametric parametrized part percentage performances perfusion positive potential priori probabilities probability processing project propose proposed questionable radiologist ranging receiver recently related representative residuals sample scientists sensitivity sessions shape shapes significantly smoothed smoothing spatial spatially specificity sphere spheres starting statistical step still studied studies subject subjects suggested supplementary surrounding taking target targeted targets task team term thresholded thresholding trade truth truths underwent univariate validation visages white whole widespread wise