title: Dynamic MR imaging of the temporomandibular joint in patients with arthrosis: relationship between contrast enhancement of the posterior disk attachment and joint pain.
abstract: OBJECTIVE
  The purpose of this study was to determine the relationship between joint pain, disk position, and the degree of contrast enhancement of the posterior disk attachment in patients with temporomandibular joint arthrosis using dynamic contrast-enhanced MR imaging.
  
  
  METHODS
  T1- and T2-weighted spin-echo and spoiled gradient-recalled acquisition in the steady state MR imaging was performed in 36 healthy volunteers and 105 patients who were asymptomatic or who had joint pain, muscular pain, or both. On T1-weighted images, the position of the disk was classified as normal and anteriorly displaced. Next, on sagittal spoiled gradient-recalled acquisition in the steady state MR images, signal intensity from teh posterior disk attachment was measured. Time-intensity curves of the signal-intensity ratio versus the time after contrast administration were obtained in each case. Diagnostic accuracy of enhancement among the clinical symptoms was assessed using receiver operating characteristic curves. Imaging findings of contrast enhancement were correlated with pain and disk position.
  
  
  RESULTS
  In quantitative measurement, a rapid enhancement pattern was seen most frequently in patients with joint-pain, whereas relatively gradual enhancement was seen in the healthy subjects and in patients who were asymptomatic or who had muscular pain. The mean peak-signal-intensity ratio of the group with joint pain was significantly higher than that of the other groups (p < .001). In the group with joint pain, anterior disk displacement without reduction was strongly associated with the mean signal-intensity ratio (p < .01). With regard to receiver operating characteristic analysis, the group with joint pain showed significantly greater accuracy than did the other groups (p < .001).
  
  
  CONCLUSIONS
  Our results suggest that prominent contrast enhancement of the posterior disk attachment on spoiled gradient-recalled acquisition in the steady state MR images may help differentiate intraarticular from extraarticular causes of pain in and around the temporomandibular joint. In the group with joint pain, anterior disk displacement without reduction was closely associated with prominent enhancement.
authors.affiliation: Department of Oral Radiology, Kagoshima University Dental School, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Suenaga
authors.forename: S
authors.initials: S
authors.lastname: Hamamoto
authors.forename: K
authors.initials: K
authors.lastname: Kawano
authors.forename: Y
authors.initials: Y
authors.lastname: Higashida
authors.forename: T
authors.initials: T
authors.lastname: Noikura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D013704:Temporomandibular Joint / Q000033:anatomy & histology / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000150:complications / Q000175:diagnosis*; D013706:Temporomandibular Joint Dysfunction Syndrome / Q000175:diagnosis