COMPARISON OF XENON-ENHANCED CT WITH ULTRAFAST CT FOR MEASUREMENT OF REGIONAL CEREBRAL BLOOD-FLOW

PURPOSE: To compare an ultrafast CT method for estimating regional cer ebral blood flow with a more commonly used xenon-enhanced CT method. M ETHODS: Xenon CT and ultrafast CT were used to estimate regional cereb ral blood flow (rCBF) in 12 healthy beagle dogs. Measurements were obt ained for left and right hemisphere, cortical gray matter, basal gangl ia, and deep white matter. The ability of each method to show differen ces in blood flow between regions of high flow (gray matter) and low f low (white matter) was evaluated, both for large (>0.75 cm3) and small (<0.5 CM3) regions of interest. In addition, side-to-side differences in rCBF were evaluated to determine the minimum difference that would suggest a significant alteration in blood flow. RESULTS: There was le ss interanimal variance in absolute rCBF measurements obtained using x enon CT; ultrafast CT appeared to accentuate rCBF differences between high flow and low flow regions. There were strong side-to-side correla tions in rCBF when measured by ultrafast CT, which suggests that this technique may be particularly useful in detecting focal alterations in rCBF restricted to one hemisphere of the brain. CONCLUSIONS: Ultrafas t CT measures of rCBF compare favorably with those obtained using xeno n CT.