title: In vivo images of the epidural space with two- and three-dimensional optical coherence tomography in a porcine model.
abstract: BACKGROUND
  No reports exist concerning in vivo optical coherence tomography visualization of the epidural space and the blood patch process in the epidural space. In this study, we produced real-time two-dimensional and reconstructed three-dimensional images of the epidural space by using optical coherence tomography in a porcine model. We also aimed to produce three-dimensional optical coherence tomography images of the dura puncture and blood patch process.
  
  
  METHODS
  Two-dimensional and three-dimensional optical coherence tomography images were obtained using a swept source optical coherence tomography (SSOCT) system. Four laboratory pigs were intubated and ventilated after the induction of general anesthesia. An 18-gauge Tuohy needle was used as a tunnel for the optical coherence tomography probe to the epidural space. Two-dimensional and three-dimensional reconstruction optical coherence tomography images of the epidural space were acquired in four stages.
  
  
  RESULTS
  In stage 1, real-time two-dimensional and reconstructed three-dimensional optical coherence tomography of the lumbar and thoracic epidural space were successfully acquired. In stage 2, the epidural catheter in the epidural space was successfully traced in the 3D optical coherence tomography images. In stage 3, water injection and lumbar puncture were successfully monitored in all study animals. In stage 4, 10 mL of fresh blood was injected into the epidural space and two-dimensional and three-dimensional optical coherence tomography images were successfully acquired.
  
  
  CONCLUSIONS
  These animal experiments suggest the potential capability of using an optical coherence tomography-based imaging needle in the directed two-dimensional and three-dimensional visualization of the epidural space. More investigations involving humans are required before optical coherence tomography can be recommended for routine use. However, three-dimensional optical coherence tomography may provide a novel, minimally invasive, and safe way to observe the spinal epidural space, epidural catheter, lumbar puncture hole, and blood patch.
authors.affiliation: Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan.|Biophotonics and Molecular Imaging Research Center, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wen-Chuan
authors.initials: WC
authors.lastname: Kuo
authors.affiliation: Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Meng-Chun
authors.initials: MC
authors.lastname: Kao
authors.affiliation: Department of Anesthesiology, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Mei-Yung
authors.initials: MY
authors.lastname: Tsou
authors.affiliation: Department of Anesthesiology, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chien-Kun
authors.identifier: http://orcid.org/0000-0002-3156-8139
authors.initials: CK
authors.lastname: Ting
mesh_terms: D000818:Animals; D004824:Epidural Space / Q000000981:diagnostic imaging*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D013552:Swine; D041623:Tomography, Optical Coherence / Q000295:instrumentation / Q000379:methods*