Cerebral blood flow on xenon CT: correlation with the blood flow detected at the common carotid artery on ultrasonography.

To correlate cerebral blood flow (CBF) on xenon CT with the flow at common carotid artery (CCA) detected by color doppler ultrasonography, 82 patients (29 men, 53 women; 20-90 yrs) were examined. They included normal volunteers (n = 33), patients with cerebral infarction (n = 8), multiple lacunar infarcts (n = 12), dementia (n = 14), and parkinson disease (n = 15). Flow at the CCA was graded as extremely low (< 0.3 l/min), low (0.3-0.4), and normal (> 0.4). CBF was measured in the following distribution: anterior, middle, posterior cerebral arteries (ACA, MCA, PCA); white matter border zones (BZ); basal ganglia (BA), thalamus in two slices. CBF may be reduced in the BZ, cortical and deep gray matter with extremely low flow at CCA. We suggest that color doppler ultrasonography may aid in triage of patients for further CBF evaluation. As some overlap in CBF exists between normal and diseased groups with respect to low flow at CCA, color doppler ultrasonography must be evaluated in combination with xenon CT to reflect cerebral blood flow.