title: Contrast enhanced ultrasound imaging for assessment of spinal cord blood flow in experimental spinal cord injury.
abstract: Reduced spinal cord blood flow (SCBF) (i.e., ischemia) plays a key role in traumatic spinal cord injury (SCI) pathophysiology and is accordingly an important target for neuroprotective therapies. Although several techniques have been described to assess SCBF, they all have significant limitations. To overcome the latter, we propose the use of real-time contrast enhanced ultrasound imaging (CEU). Here we describe the application of this technique in a rat contusion model of SCI. A jugular catheter is first implanted for the repeated injection of contrast agent, a sodium chloride solution of sulphur hexafluoride encapsulated microbubbles. The spine is then stabilized with a custom-made 3D-frame and the spinal cord dura mater is exposed by a laminectomy at ThIX-ThXII. The ultrasound probe is then positioned at the posterior aspect of the dura mater (coated with ultrasound gel). To assess baseline SCBF, a single intravenous injection (400 µl) of contrast agent is applied to record its passage through the intact spinal cord microvasculature. A weight-drop device is subsequently used to generate a reproducible experimental contusion model of SCI. Contrast agent is re-injected 15 min following the injury to assess post-SCI SCBF changes. CEU allows for real time and in-vivo assessment of SCBF changes following SCI. In the uninjured animal, ultrasound imaging showed uneven blood flow along the intact spinal cord. Furthermore, 15 min post-SCI, there was critical ischemia at the level of the epicenter while SCBF remained preserved in the more remote intact areas. In the regions adjacent to the epicenter (both rostral and caudal), SCBF was significantly reduced. This corresponds to the previously described "ischemic penumbra zone". This tool is of major interest for assessing the effects of therapies aimed at limiting ischemia and the resulting tissue necrosis subsequent to SCI.
authors.affiliation: Laboratoire d'étude de la microcirculation, Faculté de Médecine Paris Diderot Paris VII, U942; Department of orthopaedic surgery, Bicetre Universitary Hospital, Public Assistance of Paris Hospital.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Dubory
authors.affiliation: Laboratoire d'étude de la microcirculation, Faculté de Médecine Paris Diderot Paris VII, U942.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Laemmel
authors.affiliation: Institute of Medical Science, Faculty of Medicine, University of Toronto.
authors.forename: Anna
authors.initials: A
authors.lastname: Badner
authors.affiliation: Laboratoire d'étude de la microcirculation, Faculté de Médecine Paris Diderot Paris VII, U942; Department of Intensive care and Anesthesiology, Bicetre Universitary Hospital, Public Assistance of Paris Hospital.
authors.forename: Jacques
authors.initials: J
authors.lastname: Duranteau
authors.affiliation: Laboratoire d'étude de la microcirculation, Faculté de Médecine Paris Diderot Paris VII, U942.
authors.forename: Eric
authors.initials: E
authors.lastname: Vicaut
authors.affiliation: Department of orthopaedic surgery, Bicetre Universitary Hospital, Public Assistance of Paris Hospital.
authors.forename: Charles
authors.initials: C
authors.lastname: Court
authors.affiliation: Laboratoire d'étude de la microcirculation, Faculté de Médecine Paris Diderot Paris VII, U942; Department of orthopaedic surgery, Bicetre Universitary Hospital, Public Assistance of Paris Hospital; soubeyrand.marc@gmail.com.
authors.forename: Marc
authors.initials: M
authors.lastname: Soubeyrand
mesh_terms: D000818:Animals; D003199:Computer Systems; D004195:Disease Models, Animal; D007511:Ischemia / Q000000981:diagnostic imaging; D008297:Male; D051381:Rats; D012039:Regional Blood Flow / Q000502:physiology; D013116:Spinal Cord / Q000098:blood supply* / Q000000981:diagnostic imaging*; D013119:Spinal Cord Injuries / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D014463:Ultrasonography / Q000379:methods