2015 · JOURNAL OF MAGNETIC RESONANCE IMAGING

Test-Retest Reliability of Cerebral Blood Flow and Blood Oxygenation Level-Dependent Responses to Hypercapnia and Hyperoxia Using Dual-Echo Pseudo-Continuous Arterial Spin Labeling and Step Changes in the Fractional Composition of Inspired Gases

Tancredi, Felipe B., Lajoie, Isabelle, Hoge, Richard D.

Journal
JOURNAL OF MAGNETIC RESONANCE IMAGING
Année
2015
Volume
42
Numéro
4
Pages
1144-1157
Mois
OCT
DOI
10.1002/jmri.24878

Abstract

Purpose: To assess the reproducibility of blood oxygenation level-dependent / cerebral blood flow (BOLD/CBF) responses to hypercapnia/hyperoxia using dual-echo pseudo-continuous arterial spin labeling (pCASL) and step changes in inspired doses. Materials and Methods: Eight subjects were scanned twice, within 24 hours, using the same respiratory manipulation and imaging protocol. Imaging comprised a 5-minute anatomical acquisition, allowing segmentation of the gray matter (GM) tissue for further analysis, and an 18-minute pCASL functional scan. Hypercapnia/hyperoxia were induced by increasing the fraction of inspired CO2 to 5% and inspired O-2 to 60%, alternately. Reproducibility of BOLD and CBF pCASL measures was assessed by computing the inter-session coefficient of variation (CV) of the respective signals in GM. Results: BOLD and CBF measures in GM were robust and consistent, yielding CV values below 10% for BOLD hypercapnic/hyperoxic responses (which averaged 1.9 +/- 0.1% and 1.14 +/- 0.02%) and below 20% for the CBF hypercapnic response (which averaged 35 +/- 2 mL/min/100g). The CV for resting CBF was 3.5%. Conclusion: It is possible to attain reproducible measures of the simultaneous BOLD and CBF responses to blood gases, within a reasonable scan time and with whole brain coverage, using a simple respiratory manipulation and dual-echo pCASL.

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