Quantification of BOLD fMRI Parameters to Infer Cerebrovascular Reactivity of the Middle Cerebral Artery
| Autor: | Mazzetto-Betti, Kelley C., Leoni, Renata F., Pontes-Neto, Octavio M., Sturzbecher, Marcio J., Santos, Antonio C., Leite, Joao P., Silva, Afonso C., Araújo, Dráulio Barros de |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Adult
Male middle cerebral artery Brain Mapping Middle Cerebral Artery fMRI Reproducibility of Results hypercapnia Magnetic Resonance Imaging Sensitivity and Specificity Article cerebrovascular reactivity Hypercapnia Oxygen Consumption auditory stimulus Cerebrovascular Circulation Image Interpretation Computer-Assisted Humans Female Blood Flow Velocity BOLD |
| Zdroj: | Repositório Institucional da UFRN Universidade Federal do Rio Grande do Norte (UFRN) instacron:UFRN |
| Popis: | Purpose: To 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 Methods: Twenty healthy volunteers (mean age: 23.6 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-halfmaximum (FWHM), and amplitude. Results: BOLD 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. Conclusion: The 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|