title: Diagnosis of Thin-Capped Fibroatheromas in Intravascular Optical Coherence Tomography Images: Effects of Light Scattering.
abstract: Intravascular optical coherence tomography (IVOCT) images are recorded by detecting light backscattered within coronary arteries. We hypothesize that non-thin-capped fibroatheroma (TCFA) causes may scatter light to create the false appearance of IVOCT TCFA.
  
  
  
  Ten human cadaver hearts were imaged with IVOCT (n=14 coronary arteries). IVOCT and histological TCFA images were coregistered and compared. Of 21 IVOCT TCFAs (fibrous cap <65 μm, lipid arc >1 quadrant), only 8 were true histological TCFA. Foam cell infiltration was responsible for 70% of false IVOCT TCFA and caused both thick-capped fibroatheromas to appear as TCFA, and the appearance of TCFAs when no lipid core was present. Other false IVOCT TCFA causes included smooth muscle cell-rich fibrous tissue (12%) and loose connective tissue (9%). If the lipid arc >1 quadrant (obtuse) criterion was disregarded, 45 IVOCT TCFAs were identified, and sensitivity of IVOCT TCFA detection increased from 63% to 87%, and specificity remained high at 92%.
  
  
  
  We demonstrate that IVOCT can exhibit 87% (95% CI, 75%-93%) sensitivity and 92% specificity (95% CI, 86%-96%) to detect all lipid arcs (both obtuse and acute, <1 quadrant) TCFA, and we also propose new mechanisms involving light scattering that explain why other plaque components can masquerade as TCFA and cause low positive predictive value of IVOCT for TCFA detection (47% for obtuse lipid arcs). Disregarding the lipid arc >1 quadrant requirement enhances the ability of IVOCT to detect TCFA.
authors.affiliation: From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.).
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Phipps
authors.affiliation: From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.).
authors.forename: Taylor
authors.initials: T
authors.lastname: Hoyt
authors.affiliation: From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.).
authors.forename: Deborah
authors.initials: D
authors.lastname: Vela
authors.affiliation: From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.).
authors.forename: Tianyi
authors.initials: T
authors.lastname: Wang
authors.affiliation: From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.).
authors.forename: Joel E
authors.initials: JE
authors.lastname: Michalek
authors.affiliation: From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.).
authors.forename: L Maximilian
authors.initials: LM
authors.lastname: Buja
authors.affiliation: From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.).
authors.forename: Ik-Kyung
authors.initials: IK
authors.lastname: Jang
authors.affiliation: From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.).
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Milner
authors.affiliation: From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.). feldmanm@uthscsa.edu.
authors.forename: Marc D
authors.initials: MD
authors.lastname: Feldman
mesh_terms: D000368:Aged; D001706:Biopsy; D002102:Cadaver; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005355:Fibrosis; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D041623:Tomography, Optical Coherence
keywords: atherosclerosis; lipids; myocytes, smooth muscle; plaque, amyloid; tomography, optical coherence