Original Article

A Comparative Study of the Effect of Weighted or Binary Functional Brain Networks in fMRI Data Analysis

Abstract

Purpose: Graph theory is a widely used and reliable tool to quantify brain connectivity. Brain functional connectivity is modeled as graph edges employing correlation coefficients. The correlation coefficients can be used as the weight that shows the power of connectivity between two nodes or can be binarized to show the existence of a connection regardless of its strength. To binarize the brain graph two approaches, namely fixed threshold and fixed density are often used.
Materials and Methods: This paper aims to investigate the difference between weighted or binarized graphs in brain functional connectivity analysis. To achieve this goal, the brain connectivity matrices are generated employing the functional Magnetic Resonance Imaging (fMRI) data of Alzheimer's Disease (AD). After preprocessing the data, weighted and binarized connectivity matrices are constructed using a fixed threshold and fixed density techniques. Graph global features are extracted and a non-parametric statistical test is performed to analyze the performance of the methods.
Results: Results show that all three methods are powerful in distinguishing the healthy group from AD subjects. The P-Values of the weighted graph is close to the fixed threshold method.
Conclusion: Also, it is worthwhile mentioning that the fixed threshold method is robust in changing the threshold while the fixed density method is very sensitive. On the other hand, graph global measures such as clustering coefficient and transitivity, regardless of the method, show significant differences between the control and AD groups. Furthermore, the P-Values of modularity measure are very varied according to the method and the selected threshold.

1- M. Rubinov and O. Sporns, "Complex network measures of brain connectivity: uses and interpretations," Neuroimage, vol. 52, no. 3, pp. 1059-1069, 2010.
2- C. Testa et al., "A comparison between the accuracy of voxel-based morphometry and hippocampal volumetry in Alzheimer's disease," Journal of Magnetic Resonance Imaging: An Official Journal of the International Society for Magnetic Resonance in Medicine, vol. 19, no. 3, pp. 274-282, 2004.
3- J. D. Power, "Resting-State fMRI: Preclinical Foundations," in fMRI: Springer, pp. 47-63, 2020.
4- D.-E. Meskaldji, S. Morgenthaler, and D. Van De Ville, "New measures of brain functional connectivity by temporal analysis of extreme events," in 2015 IEEE 12th International Symposium on Biomedical Imaging (ISBI), IEEE, pp. 26-29, 2015.
5- M. P. Van Den Heuvel and H. E. H. Pol, "Exploring the brain network: a review on resting-state fMRI functional connectivity," European neuropsychopharmacology, vol. 20, no. 8, pp. 519-534, 2010.
6- L.-l. Gao and T. Wu, "The study of brain functional connectivity in Parkinson’s disease," Translational neurodegeneration, vol. 5, no. 1, p. 18, 2016.
7- J. V. Hull, L. B. Dokovna, Z. J. Jacokes, C. M. Torgerson, A. Irimia, and J. D. Van Horn, "Resting-state functional connectivity in autism spectrum disorders: A review," Frontiers in psychiatry, vol. 7, p. 205, 2017.
8- K. Rubia et al., "Functional connectivity changes associated with fMRI neurofeedback of right inferior frontal cortex in adolescents with ADHD," NeuroImage, vol. 188, pp. 43-58, 2019.
9- L. Zhao et al., "Altered interhemispheric functional connectivity in remitted bipolar disorder: A Resting State fMRI Study," Scientific Reports, vol. 7, no. 1, pp. 1-8, 2017.
10- A. s. Association, "2019 Alzheimer's disease facts and figures," Alzheimer's & Dementia, vol. 15, no. 3, pp. 321-387, 2019.
11- Z. Zhang et al., "Functional degeneration in dorsal and ventral attention systems in amnestic mild cognitive impairment and Alzheimer’s disease: an fMRI study," Neuroscience letters, vol. 585, pp. 160-165, 2015.
12- X. Liu et al., "Altered functional connectivity of insular subregions in Alzheimer’s disease," Frontiers in aging neuroscience, vol. 10, p. 107, 2018.
13- J. King et al., "Increased functional connectivity after listening to favored music in adults with Alzheimer dementia," The journal of prevention of Alzheimer's disease, vol. 6, no. 1, pp. 56-62, 2019.
14- F. de Vos et al., "A comprehensive analysis of resting state fMRI measures to classify individual patients with Alzheimer's disease," Neuroimage, vol. 167, pp. 62-72, 2018.
15- J. Zhao, X. Ding, Y. Du, X. Wang, and G. Men, "Functional connectivity between white matter and gray matter based on fMRI for Alzheimer's disease classification," Brain and behavior, vol. 9, no. 10, p. e01407, 2019.
16- E. Fatemizadeh and A. M. Nasrabadi, "Multiclass classification of patients during different stages of Alzheimer’s disease using fMRI time-series," Biomedical Physics & Engineering Express, 2020.
17- E. L. Dennis and P. M. Thompson, "Functional brain connectivity using fMRI in aging and Alzheimer’s disease," Neuropsychology review, vol. 24, no. 1, pp. 49-62, 2014.
18- C.-Y. Wee et al., "Identification of MCI individuals using structural and functional connectivity networks," Neuroimage, vol. 59, no. 3, pp. 2045-2056, 2012.
19- S. Gupta, Y. H. Chan, J. C. Rajapakse, and A. s. D. N. Initiative, "Decoding brain functional connectivity implicated in AD and MCI," in International Conference on Medical Image Computing and Computer-Assisted Intervention, Springer, pp. 781-789, 2019.
20- Y. Li et al., "Fusion of ULS Group Constrained High-and Low-Order Sparse Functional Connectivity Networks for MCI Classification," Neuroinformatics, vol. 18, no. 1, pp. 1-24, 2020.
21- S. Yan et al., "Multiparametric imaging hippocampal neurodegeneration and functional connectivity with simultaneous PET/MRI in Alzheimer’s disease," European Journal of Nuclear Medicine and Molecular Imaging, pp. 1-13, 2020.
22- J. Benesty, J. Chen, Y. Huang, and I. Cohen, "Pearson correlation coefficient," in Noise reduction in speech processing: Springer, pp. 1-4, 2009.
23- B. R. Logan and D. B. Rowe, "An evaluation of thresholding techniques in fMRI analysis," NeuroImage, vol. 22, no. 1, pp. 95-108, 2004.
24- C. Bordier, C. Nicolini, and A. Bifone, "Graph analysis and modularity of brain functional connectivity networks: searching for the optimal threshold," Frontiers in neuroscience, vol. 11, p. 441, 2017.
25- S. G. Mueller et al., "The Alzheimer's disease neuroimaging initiative," Neuroimaging Clinics, vol. 15, no. 4, pp. 869-877, 2005.
26- C. R. Jack Jr et al., "The Alzheimer's disease neuroimaging initiative (ADNI): MRI methods," Journal of Magnetic Resonance Imaging: An Official Journal of the International Society for Magnetic Resonance in Medicine, vol. 27, no. 4, pp. 685-691, 2008.
27- C. Yan and Y. Zang, "DPARSF: a MATLAB toolbox for" pipeline" data analysis of resting-state fMRI," Frontiers in systems neuroscience, vol. 4, p. 13, 2010.
28- N. Tzourio-Mazoyer et al., "Automated Anatomical Labeling of Activations in SPM Using a Macroscopic Anatomical Parcellation of the MNI MRI Single-Subject Brain," NeuroImage, vol. 15, no. 1, pp. 273-289, 2002/01/01/ 2002, doi: https://doi.org/10.1006/nimg.2001.0978.
29- R. Polanía, W. Paulus, A. Antal, and M. A. Nitsche, "Introducing graph theory to track for neuroplastic alterations in the resting human brain: a transcranial direct current stimulation study," Neuroimage, vol. 54, no. 3, pp. 2287-2296, 2011.
30- A. D. Cohen, D. Tomasi, E. Shokri-Kojori, A. S. Nencka, and Y. Wang, "Functional connectivity density mapping: comparing multiband and conventional EPI protocols," Brain Imaging and Behavior, vol. 12, no. 3, pp. 848-859, 2018.
31- F. Váša, E. T. Bullmore, and A. X. Patel, "Probabilistic thresholding of functional connectomes: Application to schizophrenia," Neuroimage, vol. 172, pp. 326-340, 2018.
32- M. Jalili, "Graph theoretical analysis of Alzheimer's disease: Discrimination of AD patients from healthy subjects," Information Sciences, vol. 384, pp. 145-156, 2017.
33- M. John, T. Ikuta, and J. Ferbinteanu, "Graph analysis of structural brain networks in Alzheimer’s disease: beyond small world properties," Brain Structure and Function, vol. 222, no. 2, pp. 923-942, 2017.
34- J. C. Coninck, F. A. Ferrari, A. S. Reis, K. C. Iarosz, A. M. Batista, and R. L. Viana, "Network properties of healthy and Alzheimer's brains," arXiv preprint arXiv:1905.11249, 2019.
35- M. Mijalkov, E. Kakaei, J. B. Pereira, E. Westman, G. Volpe, and A. s. D. N. Initiative, "BRAPH: A graph theory software for the analysis of brain connectivity," PloS one, vol. 12, no. 8, p. e0178798, 2017.
36- T. E. Nichols and A. P. Holmes, "Nonparametric permutation tests for functional neuroimaging: a primer with examples," Human brain mapping, vol. 15, no. 1, pp. 1-25, 2002.
37- M. R. Brier et al., "Functional connectivity and graph theory in preclinical Alzheimer's disease," Neurobiology of aging, vol. 35, no. 4, pp. 757-768, 2014.
38- A. Khazaee, A. Ebrahimzadeh, and A. Babajani-Feremi, "Identifying patients with Alzheimer’s disease using resting-state fMRI and graph theory," Clinical Neurophysiology, vol. 126, no. 11, pp. 2132-2141, 2015.
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IssueVol 7 No 3 (2020) QRcode
SectionOriginal Article(s)
DOI https://doi.org/10.18502/fbt.v7i3.4618
Keywords
Functional Connectivity Correlation Binary Graph Weighted Graph Functional Magnetic Resonance Imaging Alzheimer’s Disease

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How to Cite
1.
Ahmadi H, Fatemizadeh E, Motie Nasrabadi A. A Comparative Study of the Effect of Weighted or Binary Functional Brain Networks in fMRI Data Analysis. Frontiers Biomed Technol. 2020;7(3):160-169.