Normal and pathological connectivity in the brain under resting-state: magnetic resonance as a tool for the functional and structural study

• Grant number: 11/05934-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2011
• End date: October 31, 2014
• Field of knowledge: Health Sciences - Medicine - Medical Radiology
• Principal Investigator: Antonio Carlos dos Santos
• Grantee: Carlo Rondinoni
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Resting state studies by fMRI are carried out in order to identify the brain networks responsible for the basal functioning of the brain networks, known as default mode networks (DMN). Although considered to be in rest, subjects are unavoidably under a massive charge of environmental acoustic noise produced by the MRI equipment. Our aim was to verify if the massive auditory information input can mask the "real" DMNs. The functional volumes were acquired when 6 subjects (2 women) had their eyes opened under default EPI sequences or during soft-tone sequences (slew-rate reduction), as allowed by a Philips Achieva 3T MRI scanner. The sound pressure level difference between the default and soft sequences reached 12 dB. Experimental sessions consisted of two runs of 7 minutes each under different levels of noise. The sequence of conditions was counter-balanced between subjects. The functional volumes were preprocessed (3d motion correction, high-pass filtering) and submitted to Independent Component Analysis (ICA) with BrainVoyager software. The influence of the higher noise was evaluated by counting the BOLD components under each noise condition and comparing the functional volumes by the number of voxels in each component. The results show that a lower level of noise may uncover more components as identified blindly by the Independent Components Analysis. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

C. RONDINONI; E. AMARO JR; F. CENDES; A.C.DOS SANTOS; C.E.G. SALMON. Effect of scanner acoustic background noise on strict resting-state fMRI. Brazilian Journal of Medical and Biological Research, v. 46, n. 4, p. 359-367, 2013-04-12. (05/56447-7, 11/05934-6)

RONDINONI, CARLO; ROLO, JAICER; GARRIDO SALMON, CARLOS ERNESTO; DOS SANTOS, ANTONIO CARLOS; IEEE. Multimodal Neuroimaging in Alzheimer's Disease: Contributions of multi-voxel pattern analysis to the analysis of DTI and resting-state MRI. 2014 INTERNATIONAL WORKSHOP ON PATTERN RECOGNITION IN NEUROIMAGING, v. N/A, p. 4-pg., 2014-01-01. (11/05934-6)