Quantification of BOLD fMRI Parameters to Infer Cerebrovascular Reactivity of the Middle Cerebral Artery

Autor(es)

Mazzetto-Betti, Kelley C. ^[1] ; Leoni, Renata F. ^{[1, 2]} ; Pontes-Neto, Octavio M. ^[1] ; Sturzbecher, Marcio J. ^{[1, 3]} ; Santos, Antonio C. ^[1] ; Leite, Joao P. ^[1] ; Silva, Afonso C. ^[2] ; de Araujo, Draulio B. ^{[4, 1, 3, 5]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Neurosci & Behav Sci, FMRP, BR-14049 Ribeirao Preto - Brazil

^[2] NINDS, Cerebral Microcirculat Unit, Lab Funct & Mol Imaging, NIH, Bethesda, MD 20892 - USA

^[3] Univ Sao Paulo, Dept Phys, FFCLRP, BR-14049 Ribeirao Preto - Brazil

^[4] Univ Fed Rio Grande do Norte, Inst Brain, BR-59072970 Natal, RN - Brazil

^[5] Univ Fed Rio Grande do Norte, Onofre Lopes Univ Hosp, BR-59072970 Natal, RN - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Magnetic Resonance Imaging; v. 38, n. 5, p. 1203-1209, NOV 2013.
• Citações Web of Science: 0

Resumo

PurposeTo quantify the amplitude and temporal aspects of the blood oxygenation level-dependent (BOLD) response to an auditory stimulus during normocapnia and hypercapnia in healthy subjects in order to establish which BOLD parameters are best suited to infer the cerebrovascular reactivity (CVR) in the middle cerebral artery (MCA) territory. Materials and MethodsTwenty healthy volunteers (mean age: 23.6 3.7 years, 11 women) were subjected to a functional paradigm composed of five epochs of auditory stimulus (3 sec) intercalated by six intervals of rest (21 sec). Two levels of hypercapnia were achieved by a combination of air and CO2 while the end-tidal CO2 (ETCO2) was continually measured. An autoregressive method was applied to analyze four parameters of the BOLD signal: onset-time, time-to-peak, full-width-at-half-maximum (FWHM), and amplitude. ResultsBOLD onset time (P < 0.001) and full-width at half-maximum (FWHM) (P < 0.05) increased linearly, while BOLD amplitude decreased (P < 0.001) linearly with increasing levels of hypercapnia. Test-retest for reproducibility in five subjects revealed excellent concordance for onset time and amplitude. ConclusionThe robust linear dependence of BOLD onset time, FWHM, and amplitude to hypercapnia suggest future application of this protocol in clinical studies aimed at evaluating CVR of the MCA territory. J. Magn. Reson. Imaging 2013;38:1203-1209. (c) 2012 Wiley Periodicals, Inc. (AU)

• Processo FAPESP: 09/08691-7 - Estudo da vasorreatividade cerebral em pacientes com estenose carotidea atraves de ressonância magnética funcional.
• Beneficiário: Kelley Cristine Mazzetto Betti
• Modalidade de apoio: Bolsas no Brasil - Doutorado