title: 3-D CT and MRI co-registration in the assessment of cochlear implantation.
abstract: BACKGROUND
  The aim of this study was to evaluate the feasibility of co-registering preoperative MRI and postoperative CT and to assess the position of the electrode within the cochlea.
  
  
  METHODS
  In a series of 14 patients, high-resolution MRI datasets of the cochlea obtained before implantation and multirow CT datasets obtained after implantation were co-registered using a stereoscopic display and volume-rendering platform (Dextroscope, Volume Interactions/Bracco, Singapore). Image co-registration was performed with a semi-automatic method (multipoint plus freehand fusion).
  
  
  RESULTS
  In 2 patients the electrode was correctly inserted in the middle turn of the cochlea and the assigned rank was 4 (corresponding to the initial tract of the middle turn). In 8 patients the rank was 3, meaning that the electrode tip reached the upper portion of the basal turn. In 4 patients the rank was 2, meaning that the electrode tip reached the middle portion of the basal turn; in two of these patients, electrode kinking was observed.
  
  
  CONCLUSIONS
  Co-registration of preoperative MRI and postoperative CT is feasible and represents a unique method to assess electrode position within the membranous labyrinth.
authors.affiliation: Division of Diagnostic and Interventional Radiology of the Department of Oncology, Transplants, and Advanced Technologies in Medicine, University of Pisa, Pisa, Italy. neri@med.unipi.it
authors.forename: Emanuele
authors.initials: E
authors.lastname: Neri
authors.forename: Stefano
authors.initials: S
authors.lastname: Berrettini
authors.forename: Luca
authors.initials: L
authors.lastname: Salvatori
authors.forename: Francesca
authors.initials: F
authors.lastname: Forli
authors.forename: Stefano Sellari
authors.initials: SS
authors.lastname: Franceschini
authors.forename: Carlo
authors.initials: C
authors.lastname: Bartolozzi
mesh_terms: D000293:Adolescent; D000328:Adult; D003051:Cochlea / Q000000981:diagnostic imaging* / Q000473:pathology*; D019929:Cochlear Implantation; D006801:Humans; D008279:Magnetic Resonance Imaging; D011184:Postoperative Period; D014057:Tomography, X-Ray Computed