title: High-field and low-field MR imaging of superior glenoid labral tears and associated tendon injuries.
abstract: OBJECTIVE
  The purpose of this study was to determine the performance characteristics of high-field and low-field MR imaging for the diagnosis of a glenoid superior labral anteroposterior (SLAP) tear.
  
  
  METHODS
  High-field (n = 46) or low-field (n = 21) MR imaging was performed on 41 patients with SLAP tears and 26 patients with normal superior labra. The superior labrum was classified into one of four types on the basis of patterns of intralabral signal intensity. The relative frequency of rotator cuff tears and long head of the biceps tendinopathy was also assessed.
  
  
  RESULTS
  For the diagnosis of SLAP tear, the sensitivity of high-field MR imaging was 90% (95% confidence interval = 74%, 98%), specificity was 63% (35%, 85%), and accuracy was 80% (66%, 91%). The sensitivity of low-field MR imaging was 64% (31%, 89%), specificity was 70% (35%, 93%), and accuracy was 67% (43%, 85%). A branched linear or stellate focus of abnormal intralabral signal intensity was associated with a SLAP tear in 86% of patients. Conversely, two other labral patterns correlated with a normal superior labrum in 71% of patients. Abnormal signal intensity in the biceps tendon was seen in 15% of patients with a SLAP tear. Full-thickness (37%) and partial-thickness (31%) rotator cuff tears were often seen.
  
  
  CONCLUSIONS
  The performance characteristics of high-field MR imaging are superior to those of low-field MR imaging for the diagnosis of a superior labral tear. Rotator cuff tears can be seen in many patients with superior labral tears, but abnormal signal intensity in the biceps tendon is uncommon.
authors.affiliation: Department of Diagnostic Imaging, Brown University School of Medicine, Rhode Island Hospital, Providence 02903, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Tung
authors.forename: D
authors.initials: D
authors.lastname: Entzian
authors.forename: A
authors.initials: A
authors.lastname: Green
authors.forename: J M
authors.initials: JM
authors.lastname: Brody
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017006:Rotator Cuff / Q000473:pathology*; D000070636:Rotator Cuff Injuries; D012421:Rupture; D012680:Sensitivity and Specificity; D012782:Shoulder / Q000473:pathology*; D000070599:Shoulder Injuries; D013708:Tendon Injuries; D013710:Tendons / Q000473:pathology*