Acetazolamide vasoreactivity evaluated by transcranial power harmonic imaging and Doppler sonography.

Background: Cerebral vasoreactivity (CVR) in the major cerebral arteries evaluated by transcranial Doppler sonography has shown some correlation with CVR in the brain tissue measured by other neuroradiological modalities. To clarify vasoreactive differences in the brain tissue and the major cerebral arteries, we have evaluated the relationship of acetazolamide (ACZ) CVR between transcranial ultrasonic power harmonic imaging (PHI) and color Doppler sonography (CDS), in cases ofparenchymal pathology with and without occlusive vascular lesions.

Materials And Methods: The subjects were 31 stroke patients with intraparenchymal pathologies, 15 with (occlusive group) and 16 without (non-occlusive group) occlusive carotid and/or middle cerebral artery lesions. CVR based on values before/after ACZ (angle-collected CDS velocity in the middle and posterior cerebral arteries, PHI contrast area size, peak intensity, time to peak intensity), and correlation of CVR between PHI and CDS were compared between the side with and without lesions in both groups.

Findings: (a) PHI CVR tended to be more disturbed than CDS CVR. CVR side differences were not significant. (b) CVR correlations between PHI and CDS were always lower in the pathological sides.

Conclusions: CVR in brain tissue evaluated by PHI is susceptible to disturbance in comparison with CDS, due to both parenchymal and vascular occlusive pathologies.