title: Detection of plaque structure and composition using OCT combined with two-photon luminescence (TPL) imaging.
abstract: OBJECTIVE
  Atherosclerosis and plaque rupture leads to myocardial infarction and stroke. A novel hybrid optical coherence tomography (OCT) and two-photon luminescence (TPL) fiber-based imaging system was developed to characterize tissue constituents in the context of plaque morphology.
  
  
  METHODS
  Ex vivo coronary arteries (34 regions of interest) from three human hearts with atherosclerotic plaques were examined by OCT-TPL imaging. Histological sections (4 μm in thickness) were stained with Oil Red O for lipid, Von Kossa for calcium, and Verhoeff-Masson Tri-Elastic for collagen/elastin fibers and compared with imaging results.
  
  
  RESULTS
  Biochemical components in plaques including lipid, oxidized-LDL, and calcium, as well as a non-tissue component (metal) are distinguished by multi-channel TPL images with statistical significance (P < 0.001). TPL imaging provides complementary optical contrast to OCT (two-photon absorption/emission vs scattering). Merged OCT-TPL images demonstrate the distribution of lipid deposits in registration with detailed plaque surface profile.
  
  
  CONCLUSIONS
  Results suggest that multi-channel TPL imaging can effectively identify lipid sub-types and different plaque components. Furthermore, fiber-based hybrid OCT-TPL imaging simultaneously detects plaque structure and composition, improving the efficacy of vulnerable plaque detection and characterization.
authors.affiliation: Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas.
authors.forename: Tianyi
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas.
authors.forename: Austin
authors.initials: A
authors.lastname: McElroy
authors.affiliation: Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas.|South Texas Veterans Health Care System, San Antonio, Texas.
authors.forename: David
authors.initials: D
authors.lastname: Halaney
authors.affiliation: Texas Heart Institute, Houston, Texas.
authors.forename: Deborah
authors.initials: D
authors.lastname: Vela
authors.affiliation: Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas.
authors.forename: Edmund
authors.initials: E
authors.lastname: Fung
authors.affiliation: Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas.
authors.forename: Shafat
authors.initials: S
authors.lastname: Hossain
authors.affiliation: Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Phipps
authors.affiliation: Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas.
authors.forename: Bingqing
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas.
authors.forename: Biwei
authors.initials: B
authors.lastname: Yin
authors.affiliation: Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas.|South Texas Veterans Health Care System, San Antonio, Texas.
authors.forename: Marc D
authors.initials: MD
authors.lastname: Feldman
authors.affiliation: Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Milner
mesh_terms: D000368:Aged; D003331:Coronary Vessels / Q000473:pathology*; D006801:Humans; D066298:In Vitro Techniques; D008163:Luminescent Measurements / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: atherosclerotic plaque; calcium; collagen/elastin fiber; hybrid imaging; lipid; optical coherence tomography; oxidized-LDL; photonic crystal fiber; two-photon luminescence imaging