Optimization of CO2 arteriography based on flow regime maps of co-current gas-liquid pulsatile flow

摘要

Abstract: The intravascular use of CO$-2$/ as a contrast medium for diagnosis of vaso-occlusive disease has the potential of improved safety and reduced cost compared to conventional contrast solutions. Optimal imaging using any gaseous contrast medium is strongly dependent on the fluid mechanics of pulsatile gas-liquid flow. Gas-liquid flow regimes can be designated by the visually identifiable patterns of annular flow, stratified flow, intermittent flow, and dispersed bubble flow. This paper presents an analytically developed flow regime map for gas-liquid pulsatile flow and preliminary experimental results testing the flow regime map predictions. Preliminary experimental results confirm analytical predictions: (1) Use of CO$-2$/ for intervascular vaso- occlusive imaging under typical conditions may result in a periodic intermittent flow; (2) Periodic intermittent flow is encountered at lower liquid and gas flow rates than is steady- state intermittent flow; (3) Reliable prediction of the flow regime in coordination with precise CO2 delivery can be used to prescribe a flow regime optimal for intravascular vaso- occlusive imaging. !0