QUANTITATIVE HIGH-RESOLUTION MEASUREMENT OF CEREBROVASCULAR PHYSIOLOGY WITH SLIP-RING CT

PURPOSE: To implement and validate spiral slip-ring CT for use in cere brovascular studies. METHODS: Continuous data were acquired from an ex perimental, 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 cerebra l blood flow (CBF) were constructed with voxel-by-voxel gamma variate fitting. Reproducibility studies, different injection volumes and site s, and CO2 challenge were applied to verify the technique. RESULTS: Av erage absolute cortical gray and white matter and basal ganglia result s 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 respon se was significant in gray and white matter, as well as in the basal g anglia. CONCLUSION: Functional CT and constructed functional maps prov ide an optimal, high-resolution tool with which to visualize cerebrova scular parameters and their changes.