Monitoring of brain tissue perfusion utilizing a transducer holder for transcranial color duplex sonography.

Objective: We have improved a transducer holder for transcranial color duplex sonography (TCDS) monitoring via both the temporal and foraminal windows (TW/FW). The objective is to clarify the clinical usefulness of and identify problems with TCDS monitoring in the evaluation of brain tissue perfusion.

Methods: Brain tissue perfusion was monitored in 11 patients (ages 31-94, mean 66). After an intravenous bolus, power modulation imaging (PMI) in all cases and second harmonic imaging (SHI) in two cases were evaluated at the diencephalic horizontal plain via bilateral (6 cases) and unilateral (5 cases) TWs. After a transducer was installed into the holder, acetazolamide (ACZ) cerebral vasoreactivity utilizing PMI was evaluated in ten cases.

Results: PMI proved superior to SHI in the quantitative evaluation of the bilateral hemispheres via the unilateral TWs. Brain tissue perfusion could be precisely quantified before/after ACZ in the same regions of interest (ROI). All patients could be monitored continuously by one examiner. Fixed-probe shifts during monitoring were easily readjustable. Owing to re-fixation for contra-lateral TW monitoring, it was not possible to evaluate precisely in the same ROIs.

Conclusion: TCDS monitoring succeeds in continuously and quantitatively evaluating precise and reproducible intracranial hemodynamics in the brain tissue.