Acetazolamide vasoreactivity evaluated by transcranial harmonic perfusion imaging: relationship with transcranial Doppler sonography and dynamic CT.
To establish the reliability and clinical significance of transcranial ultrasonic harmonic perfusion imaging (HPI), we evaluated HPI's relationships with transcranial Doppler (TCD) and with dynamic CT (DCT), during acetazolamide (ACZ) vasoreactivity tests.


METHODS
The subjects were 12 neurological patients. Time-averaged maximum velocity (TAVMX) in the middle (MCA) and posterior cerebral arteries was measured by TCD. Time-intensity (-density) curves of HPI (DCT) after bolus intravenous contrast injections were created in 3 regions of interest (ROI) on the axial plane involving the temporal lobe, basal ganglia, and thalamus on both sides. Assessments of vasoreactivity were based on comparisons conducted before and after ACZ administration in terms of: a) relative changes (%delta) of the TCD TAVMX, b) HPI contrast area enlargement, c) %delta of calculated cerebral blood volume and flow of the HPI and DCT.


RESULTS
1) TCD vasoreactivity decrease in the left MCA tended to correlate with lower frequency of HPI contrast area enlargement on the left side. 2) HPI and DCT vasoreactivity tended to be disturbed in the same side ROIs.


CONCLUSIONS
Transcranial HPI achieves repeatable non-invasive bedside evaluation of cerebrovascular reserve capacity through qualitative and quantitative measurements of brain tissue perfusion, and will have clinical value in pathophysiological follow-up and therapeutic effectiveness determination of neurointensive care patients.
Shiogai
T
T
Department of Clinical Neurosciences, Kyoto Takeda Hospital, Nishinanajo, Kyoto, Japan. shiogait@pop11.odn.ne.jp
Koshimura
M
M
Murata
Y
Y
Nomura
H
H
Doi
A
A
Makino
M
M
Mizuno
T
T
Nakajima
K
K
Furuhata
H
H
D000086:Acetazolamide / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002536:Cerebral Arteries / Q000000981:diagnostic imaging*; D003287:Contrast Media; D006801:Humans; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D018615:Ultrasonography, Doppler, Color; D018616:Ultrasonography, Doppler, Duplex; D017585:Ultrasonography, Doppler, Transcranial; D014666:Vasomotor System / Q000000981:diagnostic imaging* / Q000187:drug effects*
D003287:Contrast Media; D000086:Acetazolamide