Intravascular near-infrared fluorescence imaging with intravascular ultrasound guidance

摘要

Intravascular near-infrared fluorescence (NIRF) imaging is a new approach for characterizing the physiological features of atherosclerotic plaque, but random catheter positioning within the vessel results in non-quantitative measurements due to light attenuation through variable distances through blood. We hypothesized that the construction of a combined NIRF-intravascular ultrasound (IVUS) catheter would enable tracking of the catheter position within the blood vessel and permit corrections to NIRF measurements taken at variable distances from the vessel wall. In this study, a combined NIRF-IVUS catheter was designed, co-registered NIRF and IVUS data was acquired in vessel phantoms and ex vivo arteries, depth-dependent attenuation of the fluorescent signal was corrected by an analytical light propagation model. Average root-mean-square error between NIRF estimates of fluorophore concentrations and known concentrations of fluorescent targets in coronary artery phantoms improved from 94.9% to 16.2% following NIRF corrections. We demonstrate that catheter-to-vessel wall distances derived from IVUS imaging can be employed to correct for inaccuracies caused by random NIRF catheter sensing distances.