Assessing the Accuracy of Calculations of the Functional Changes in CMRO2 From Blood Oxygenation Data

Alberto L. Vazquez¹, Mitsuhiro Fukuda¹, Seong-Gi Kim¹

The accuracy of blood oxygenation data (i.e. BOLD fMRI) to calculate the changes in CMRO2 was examined. A systematic error is introduced in CMRO2 calculations when a fully oxygenated arterial input is assumed; however, this error did not affect the temporal estimates of CMRO2. The changes in tissue oxygen tension and blood oxygenation were in near equilibrium over a time-scale of 1 to 2 s, indicating that steady-state models are reasonable. CBV measurements are important for BOLD fMRI calibration in order to obtain reliable CMRO2 estimates.