title: Feasibility study of magnetic resonance imaging-guided intranasal flexible microendoscopy.
abstract: Interventional magnetic resonance imaging (MRI) offers potential advantages over conventional interventional modalities such as X-ray fluoroscopy, ultrasonography, and computed tomography (CT). In particular, it does not use ionizing radiation, can provide high-quality images, and allows acquisition of oblique sections. We have carried out a feasibility study on the use of interventional MRI to track a flexible microendoscope in the paranasal sinuses. In this cadaver study, high-speed MRI was used to track a passive marker attached to the end of the endoscope. Automatic image registration algorithms were used to transfer the coordinates of the endoscope tip into the preoperative MRI and CT images, enabling us to display the position of the endoscope in reformatted orthogonal views or in a rendered view of the preoperative images. The endoscope video images were digitized and could be displayed alongside an approximately aligned, rendered preoperative image. Intraoperative display was provided in the scanner room by means of an liquid crystal display (LCD) projector. We estimate the accuracy of the endoscope tracking to be approximately 2 mm.
authors.affiliation: Division of Radiological Sciences, UMDS, Guy's Hospital, London, United Kingdom. d.hill@umds.ac.uk
authors.forename: D L
authors.initials: DL
authors.lastname: Hill
authors.forename: L A
authors.initials: LA
authors.lastname: Langsaeter
authors.forename: P N
authors.initials: PN
authors.lastname: Poynter-Smith
authors.forename: C L
authors.initials: CL
authors.lastname: Emery
authors.forename: P E
authors.initials: PE
authors.lastname: Summers
authors.forename: S F
authors.initials: SF
authors.lastname: Keevil
authors.forename: J P
authors.initials: JP
authors.lastname: Pracy
authors.forename: R
authors.initials: R
authors.lastname: Walsh
authors.forename: D J
authors.initials: DJ
authors.lastname: Hawkes
authors.forename: M J
authors.initials: MJ
authors.lastname: Gleeson
mesh_terms: D000465:Algorithms; D002102:Cadaver; D003287:Contrast Media; D003626:Data Display; D019723:Endoscopes; D004867:Equipment Design; D005240:Feasibility Studies; D005471:Fluoroscopy; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007430:Intraoperative Care; D008029:Lighting; D008279:Magnetic Resonance Imaging; D008846:Micromanipulation / Q000295:instrumentation*; D008904:Miniaturization; D010256:Paranasal Sinuses / Q000033:anatomy & histology* / Q000601:surgery; D018583:Pliability; D015641:Radiography, Interventional; D015642:Radiology, Interventional; D013813:Therapy, Computer-Assisted; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography; D014741:Video Recording
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA