title: Magnetic resonance imaging of intraoral hard and soft tissues using an intraoral coil and FLASH sequences.
abstract: OBJECTIVE
  To ascertain the feasibility of MRI as a non-ionizing protocol for routine dentomaxillofacial diagnostic imaging. Wireless coils were used for MRI of intraoral hard and soft tissues.
  
  
  METHODS
  FLASH MRI was applied in vivo with a mandible voxel size of 250 × 250 × 500 μm3, FOV of 64 × 64 × 28 mm3and acquisition time of 3:57 min and with a maxilla voxel size of 350 μm3and FOV of 34 cm3in 6:40 min. Ex vivo imaging was performed in 4:38 min, with a resolution of 200 μm3and FOV of 36.5 cm3. Cone beam (CB) CT of the mandible and subjects were acquired. MRI was compared to CBCT and histological sections. Deviations were calculated with intraclass correlation coefficient (ICC) and coefficient of variation (cv).
  
  
  RESULTS
  A high congruence between CBCT, MRI and specimens was demonstrated. Hard and soft tissues including dental pulp, periodontium, gingiva, cancellous bone and mandibular canal contents were adequately displayed with MRI.
  
  
  CONCLUSIONS
  Imaging of select intraoral tissues was achieved using custom MRI protocols with an easily applicable intraoral coil in a clinically acceptable acquisition time. Comparison with CBCT and histological sections helped demonstrate dimensional accuracy of the MR images. The course of the mandibular canal was accurately displayed with CBCT and MRI.
  
  
  CONCLUSIONS
  • MRI is a clinically available diagnostic tool in dentistry • Intraoral hard and soft tissues can be imaged with a high resolution with MRI • The dimensional accuracy of MRI is comparable to cone beam CT.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany. tabea.fluegge@uniklinik-freiburg.de.
authors.forename: Tabea
authors.initials: T
authors.lastname: Flügge
authors.affiliation: Medical Physics, Department of Radiology, University Medical Center Freiburg, Breisacher Str. 60, 79106, Freiburg, Germany.
authors.forename: Jan-Bernd
authors.initials: JB
authors.lastname: Hövener
authors.affiliation: Medical Physics, Department of Radiology, University Medical Center Freiburg, Breisacher Str. 60, 79106, Freiburg, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Ludwig
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany.
authors.forename: Anne-Kathrin
authors.initials: AK
authors.lastname: Eisenbeiss
authors.affiliation: Institute of Anatomy and Cell Biology, Albert Ludwig University of Freiburg, Albertstr. 17, 79104, Freiburg, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Spittau
authors.affiliation: Medical Physics, Department of Radiology, University Medical Center Freiburg, Breisacher Str. 60, 79106, Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hennig
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Schmelzeisen
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Nelson
mesh_terms: D000328:Adult; D054893:Cone-Beam Computed Tomography; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging*; D009055:Mouth / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results
keywords: Accuracy; Cone beam computed tomography; Dental Implantation; Dimensional measurement; Magnetic resonance imaging