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

• Main Authors: Pier-Luc Tardif, Marie-Jeanne Bertrand, Maxime Abran, Alexandre Castonguay, Joël Lefebvre, Barbara E. Stähli, Nolwenn Merlet, Teodora Mihalache-Avram, Pascale Geoffroy, Mélanie Mecteau, David Busseuil, Feng Ni, Abedelnasser Abulrob, Éric Rhéaume, Philippe L’Allier, Jean-Claude Tardif, Frédéric Lesage
• Format: Article
• Language: English
• Published: MDPI AG 2016-12-01
• Series: International Journal of Molecular Sciences
• Subjects: intravascular ultrasound (IVUS); near-infrared fluorescence (NIRF); atherosclerosis; ex vivo three-dimensional (3D) histology; optical coherence tomography (OCT); confocal fluorescence microscopy
• Online Access: http://www.mdpi.com/1422-0067/17/12/2110

Atherosclerotic cardiovascular diseases are characterized by the formation of a plaque in the arterial wall. Intravascular ultrasound (IVUS) provides high-resolution images allowing delineation of atherosclerotic plaques. When combined with near infrared fluorescence (NIRF), the plaque can also be studied at a molecular level with a large variety of biomarkers. In this work, we present a system enabling automated volumetric histology imaging of excised aortas that can spatially correlate results with combined IVUS/NIRF imaging of lipid-rich atheroma in cholesterol-fed rabbits. Pullbacks in the rabbit aortas were performed with a dual modality IVUS/NIRF catheter developed by our group. Ex vivo three-dimensional (3D) histology was performed combining optical coherence tomography (OCT) and confocal fluorescence microscopy, providing high-resolution anatomical and molecular information, respectively, to validate in vivo findings. The microscope was combined with a serial slicer allowing for the imaging of the whole vessel automatically. Colocalization of in vivo and ex vivo results is demonstrated. Slices can then be recovered to be tested in conventional histology.