Abstract 4367: Hybrid Ultrasound and Optical Imaging Catheter for Vascular Disease Characterization
Introduction: Intravascular ultrasound (IVUS) can image through blood and assess vessel diameter, plaque size and calcifications, but provides limited information on plaque composition. Optical coherence tomography (OCT) can identify thin fibrous caps, necrotic regions, thrombus and debris with embolic potential, but requires displacement of blood and has limited tissue penetration.
Hypothesis: IVUS and OCT can be implemented on a dual-modality catheter in a configuration that enables precise co-registration for improved identification of plaque composition and morphology.
Methods: We built a 40 MHz IVUS transducer and an OCT probe, mounted in a custom 4F catheter, with IVUS and OCT aligned for co-planar imaging (a). Pullback imaging was done on a fixed segment of a right coronary artery acquired from autopsy.
Results: IVUS showed an eccentric calcified plaque (4 to 7 o’clock) and a large field of view, enabling delineation of the border between the media and adventitia (b, arrowhead). OCT identified regions of varying fibrous cap thickness as well as the heterogeneous composition of the complex plaque with calcification (c). A composite image (d) from co-registered IVUS and OCT is shown to correlate well with Movat histology (e) from serial cross-sections.
Conclusions: This study has demonstrated the feasibility of constructing hybrid IVUS/OCT catheters with precise co-registration. Compared with standalone imaging catheters, hybrid IVUS/OCT has the potential to provide more information on plaque composition and plaque burden. It also provides a convenient method for identifying regions of interest by IVUS before displacing blood to enable OCT imaging.