Marco Piccirelli1, Christiaan Hendrik Bas van Niftrik2, Oliver Bozinov2, Athina Pangalu1, Antonio Valavanis1, Luca Regli2, and Jorn Fierstra2
1Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland, 2Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
Our iterative algorithm evaluates transient
phases of BOLD fMRI signal dynamics during a CO2 pseudo-square wave challenge
and optimizes CO2 arrival time determination to increase sensitivity and
reliability of cerebrovascular reactivity analysis.
On 25 healthy controls and unilateral
internal carotid occlusion patients, all BOLD-derived parameters maps are normalized
in MNI space and combined for reference atlases and assess alterations within single
The transient phase durations, temporal
delay maps and dynamic and static CVR maps were calculated.
We determined the optimal CO2 arrival time
and found that excluding the transient phases resulted in the best fit to the physiological