title: Biochemical analysis of the articular disc of the temporomandibular joint with magnetic resonance T2 mapping: a feasibility study.
abstract: OBJECTIVE
  Symptoms of temporomandibular joint (TMJ) dysfunction can seriously compromise patients' quality of life. The aim of our study was to use magnetic resonance imaging (MRI) T2 mapping of the articular disc to determine whether T2 mapping of the TMJ disc is feasible in routine clinical imaging and to assess the normal T2 relaxation time distribution within the TMJ.
  
  
  METHODS
  Included were ten asymptomatic volunteers without pain, any mouth-opening limitations, or any clicking phenomena. MR imaging was performed on a 3-T MR scanner using a flexible, dedicated, eight-channel multielement coil. T2 mapping was performed in the oblique sagittal plane. The regions of interest (ROIs) for the T2 relaxation time maps of the disc were selected manually.
  
  
  RESULTS
  The mean values for ROIs ranged between 22.4 and 28.8 ms, and the mean for all ROIs was 26.0 ± 5.0 ms. Intraclass correlation (ICC) for interobserver variability was 0.698, and ICC for intraobserver variability was 0.861. There was no statistically significant difference between raters (p = 0.091) or sides (p = 0.810).
  
  
  CONCLUSIONS
  The T2 mapping technique enables ultrastructural analysis of the composition of TMJ disc. This biochemical technique is feasible in vivo, as shown in our study, when a high-field (3 T) MR and a dedicated TMJ coil are used.
  
  
  CONCLUSIONS
  T2 mapping as a biochemical technique, together with morphological MRI, may help to gain more insights into the physiology and into the pathophysiology of the articular disc in the TMJ noninvasively and in vivo.
authors.affiliation: Department of Prosthodontics, Bernhard Gottlieb University of Dentistry, Medical University of Vienna, Sensengasse 2a, 1090, Vienna, Austria, martina.schmid-schwap@meduniwien.ac.at.
authors.forename: Martina
authors.initials: M
authors.lastname: Schmid-Schwap
authors.forename: Margit
authors.initials: M
authors.lastname: Bristela
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Pittschieler
authors.forename: Astrid
authors.initials: A
authors.lastname: Skolka
authors.forename: Pavol
authors.initials: P
authors.lastname: Szomolanyi
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.forename: Eva
authors.initials: E
authors.lastname: Piehslinger
authors.forename: Siegfried
authors.initials: S
authors.lastname: Trattnig
mesh_terms: D000328:Adult; D005240:Feasibility Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D013704:Temporomandibular Joint / Q000033:anatomy & histology* / Q000473:pathology; D019224:Temporomandibular Joint Disc / Q000033:anatomy & histology* / Q000473:pathology