USE OF A DOPPLER GUIDE-WIRE FOR INTRAVASCULAR BLOOD-FLOW MEASUREMENTS- A VALIDATION-STUDY FOR POTENTIAL NEUROLOGIC ENDOVASCULAR APPLICATIONS

PURPOSE: To conduct a validation study of a Doppler guide wire for pot ential neuroendovascular applications. METHODS: A 12-MHz, 0.018-inch D oppler guide wire was evaluated in eight swine under various blood flo w conditions using two types of in vivo cerebrovascular models (physio logic and arteriovenous shunting). Flow conditions were mechanically a nd pharmacologically altered. Doppler average peak velocity was compar ed with volumetric blood flow, and flow profile corrections were calcu lated and analyzed. Qualitative aspects of the Doppler guide wire spec tra were also assessed. RESULTS: Plots of average peak velocity versus volumetric blood flow showed excellent linear relationships (r(2) >0. 94), which were maintained at high flow conditions (average peak veloc ity, 99 to 236 cm/sec; volumetric blood flow, 392 to 889 mL/min). Valu es of flow profile correction varied from 0.43 to 0.94 and showed no c onsistent relationship to changes in volumetric blood flow. CONCLUSION S: The excellent correlation between average peak velocity and volumet ric blood flow over a wide range of blood flow conditions and the addi tional qualitative information of the Doppler guide wire spectra estab lish a foundation for clinical implementation. The unpredictable varia tions of flow profile corrections remain obstacles for calculating vol umetric blood flow based on Doppler guide wire average peak velocity.