title: Image fusion of CT and MRI for the visualization of the auditory and vestibular system.
abstract: The aim of this study was to perform a realistic visualization of the auditory and vestibular system using volume data sets from high-resolution computed tomography (HR-CT) and high-resolution magnetic resonance imaging (HR-MRI). - In 10 patients with conductive and/or sensorineural hearing loss, vertigo and tinnitus, HR-CT and HR-MRI of the petrous bone were performed consecutively. CT was performed with a 16-slice computed tomography scanner using a high spatial resolution. MRI was performed with a 3.0 Tesla scanner using a three-dimensional-constructive interference in steady state (3D-CISS) gradient-echo, and T2-weighted, unenhanced and gadolinium (GD)-enhanced T1-weighted turbo spin-echo sequences. The middle ear structures were interactively segmented and visualized with a color-coded shaded-surface rendering method using the HR-CT volume data sets. The inner ear structures were interactively segmented and visualized with a color-coded shaded-surface rendering method using the high-resolution 3D-CISS MRI volume data sets. Finally, both shaded-surface rendered models were superimposed semi-automatically using a commercial available software program to visualize the auditory and vestibular system. - The representation of the middle and inner ear structures with image fusion of HR-CT and HR-MRI takes advantage of both the high bony contrast of HR-CT and the high soft tissue contrast discrimination and sensitivity to fluids of HR-MRI, as well as the high spatial resolution of both modalities. In comparison to the fused axial CT/MRI, the images of 3D CT/MRI fusion facilitates a clear representation and better spatial orientation. - The middle and inner ear consists of bony structures, soft tissue structures and fluid-filled spaces. For this reason, the image fusion of volume data sets from HR-CT and HR-MRI allowed an optimized and realistic visualization of the auditory and vestibular system.
authors.affiliation: Department of Nuclear Medicine, Technical University Munich, Ismaninger Str. 22, D-81675 Munich, Germany. m.seemann@lrz.tum.de
authors.forename: M D
authors.initials: MD
authors.lastname: Seemann
authors.forename: J
authors.initials: J
authors.lastname: Beltle
authors.forename: M
authors.initials: M
authors.lastname: Heuschmid
authors.forename: H
authors.initials: H
authors.lastname: Löwenheim
authors.forename: H
authors.initials: H
authors.lastname: Graf
authors.forename: C D
authors.initials: CD
authors.lastname: Claussen
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D019786:Gadolinium DTPA; D006314:Hearing Loss, Conductive / Q000473:pathology*; D006319:Hearing Loss, Sensorineural / Q000473:pathology*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D014012:Tinnitus / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014717:Vertigo / Q000473:pathology*
chemical_list: D019786:Gadolinium DTPA