title: Intravascular optical coherence tomography light scattering artifacts: merry-go-rounding, blooming, and ghost struts.
abstract: We sought to elucidate the mechanisms underlying two common intravascular optical coherence tomography (IV-OCT) artifacts that occur when imaging metallic stents: “merry-go-rounding” (MGR), which is an increase in strut arc length (SAL), and “blooming,” which is an increase in the strut reflection thickness (blooming thickness). Due to uncontrollable variables that occur in vivo, we performed an in vitro assessment of MGR and blooming in stented vessel phantoms. Using Xience V and Driver stents, we examined the effects of catheter offset, intimal strut coverage, and residual blood on SAL and blooming thickness in IV-OCT images. Catheter offset and strut coverage both caused minor MGR, while the greatest MGR effect resulted from light scattering by residual blood in the vessel lumen, with 1% hematocrit (Hct) causing a more than fourfold increase in SAL compared with saline (p<0.001 ). Residual blood also resulted in blooming, with blooming thickness more than doubling when imaged in 0.5% Hct compared with saline (p<0.001 ). We demonstrate that a previously undescribed mechanism, light scattering by residual blood in the imaging field, is the predominant cause of MGR. Light scattering also results in blooming, and a newly described artifact, three-dimensional-MGR, which results in “ghost struts” in B-scans.
authors.affiliation: The University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United StatesbSouth Texas Veterans Health Care System, The Department of Veterans Affairs, San A.
authors.forename: J Jacob
authors.initials: JJ
authors.lastname: Mancuso
authors.affiliation: The University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United StatesbSouth Texas Veterans Health Care System, The Department of Veterans Affairs, San A.
authors.forename: David L
authors.initials: DL
authors.lastname: Halaney
authors.affiliation: The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States.
authors.forename: Sahar
authors.initials: S
authors.lastname: Elahi
authors.affiliation: The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States.
authors.forename: Derek
authors.initials: D
authors.lastname: Ho
authors.affiliation: The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States.
authors.forename: Tianyi
authors.initials: T
authors.lastname: Wang
authors.affiliation: The University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States.
authors.forename: Yongjian
authors.initials: Y
authors.lastname: Ouyang
authors.affiliation: Leiden University Medical Center, Division of Image Processing, Department of Radiology, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
authors.forename: Jouke
authors.initials: J
authors.lastname: Dijkstra
authors.affiliation: The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Milner
authors.affiliation: The University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United StatesbSouth Texas Veterans Health Care System, The Department of Veterans Affairs, San A.
authors.forename: Marc D
authors.initials: MD
authors.lastname: Feldman
mesh_terms: D000818:Animals; D016477:Artifacts; D001790:Blood Physiological Phenomena; D057510:Endovascular Procedures / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D007834:Lasers; D008027:Light; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D015607:Stents; D013552:Swine; D041623:Tomography, Optical Coherence / Q000379:methods*