Validating Intravascular Imaging with Serial Optical Coherence Tomography and Confocal Fluorescence Microscopy

Area of Science:

• Cardiovascular Research
• Biomedical Imaging
• Histopathology

Background:

• Atherosclerotic cardiovascular diseases involve arterial plaque formation.
• Intravascular ultrasound (IVUS) offers high-resolution plaque imaging.
• Near-infrared fluorescence (NIRF) enables molecular-level plaque analysis using biomarkers.

Purpose of the Study:

• To develop and present a system for automated volumetric histology of excised aortas.
• To spatially correlate ex vivo histology with in vivo IVUS/NIRF imaging.
• To validate in vivo findings of lipid-rich atheroma in cholesterol-fed rabbits.

Main Methods:

• A dual-modality IVUS/NIRF catheter was used for in vivo imaging in rabbit aortas.
• Ex vivo 3D histology was performed using optical coherence tomography (OCT) and confocal fluorescence microscopy.
• An automated serial slicer integrated with the microscope enabled whole-vessel imaging.

Main Results:

• The system achieved automated volumetric histology of excised aortas.
• Spatially correlated results between in vivo IVUS/NIRF and ex vivo 3D histology were demonstrated.
• High-resolution anatomical and molecular information was obtained, validating in vivo findings.

Conclusions:

• The presented system enables precise, automated 3D histological mapping of atherosclerotic plaques.
• This approach allows for robust spatial correlation between in vivo imaging and ex vivo validation.
• The methodology facilitates detailed molecular and anatomical characterization of atheroma.