Quantitative high-resolution measurement of cerebrovascular physiology with slip-ring CT.

PURPOSE To implement and validate spiral slip-ring CT for use in cerebrovascular studies.

METHODS Continuous data were acquired from an experimental, first-pass, iodine contrast, bolus study by unidirectional X-ray tube rotation, and images were reconstructed at 100-millisecond intervals. Functional maps of cerebral blood volume (CBV) and cerebral blood flow (CBF) were constructed with voxel-by-voxel gamma variate fitting. Reproducibility studies, different injection volumes and sites, and CO2 challenge were applied to verify the technique.

RESULTS Average absolute cortical gray and white matter and basal ganglia results were reproducible within +/- 0.8 ml/100 g for CBV and +/- 20 ml/100 g per minute for CBF, CBV response to changing arterial CO2 tension was significant only in cortical gray matter and basal ganglia; CBF response was significant in gray and white matter, as well as in the basal ganglia.

CONCLUSION Functional CT and constructed functional maps provide an optimal, high-resolution tool with which to visualize cerebrovascular parameters and their changes.