title: Transcranial contrast diminution imaging of the human brain: a pilot study in healthy volunteers.
abstract: Analysis of contrast diminution kinetics after bubble destruction is a new aspect in harmonic imaging. The purpose of this study was to investigate this approach to human cerebral perfusion. A total of 12 healthy volunteers were investigated transtemporally (Philips SONOS 5500, S4-probe, 1.8 to 3.6 MHz, 10 cm) at two ultrasound (US) contrast agent (UCA) infusion rates (0.5 and 1.0 mL/min of Optison). After achieving a steady-state, a set of 12 US pulses (6.67 Hz, MI 1.6) was applied. Time-intensity plots of three regions-of-interest (ROIs) (thalamus, white matter and cortex) were analyzed, using an exponential curve fit (I((t)) = I(0)e(-betat) + B). A total of 20 of 20 successful investigations showed a signal decrease after pulsed US application. In all cases, it was possible to generate exponential time-intensity curves. Half-life (T(1/2) = ln2/beta) and baseline intensity (B) showed a significant dependence on infusion rate (p = 0.01). At 1.0 mL/min, T(1/2) also depended on investigation depth (p = 0.01). It is possible to assess contrast diminution kinetics in human cerebral microcirculation. This new approach may provide additional information on cerebral perfusion within a short investigation time.
authors.affiliation: Department of Neurology, University Hospital Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Meyer
authors.forename: Günter
authors.initials: G
authors.lastname: Seidel
mesh_terms: D000328:Adult; D000418:Albumins / Q000493:pharmacokinetics; D002560:Cerebrovascular Circulation; D003287:Contrast Media / Q000493:pharmacokinetics; D004334:Drug Administration Schedule; D005260:Female; D005466:Fluorocarbons / Q000493:pharmacokinetics; D006207:Half-Life; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008833:Microcirculation; D008863:Microspheres; D008875:Middle Aged; D010865:Pilot Projects; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*
chemical_list: D000418:Albumins; D003287:Contrast Media; C099458:FS 069; D005466:Fluorocarbons