title: Comparison study of indirect MR arthrography and direct MR arthrography of the shoulder.
abstract: OBJECTIVE
  To compare the diagnostic value of indirect magnetic resonance arthrography (I-MRA) with that of direct MR arthrography (D-MRA) for labral tears, rotator cuff tears, and long head of biceps tendon (LHBT) tears using a 3-T MR unit.
  
  
  METHODS
  Institutional review board approval was given; written informed consent was obtained from all patients. From November 2005 to June 2006, 19 patients (eight men and 11 women; mean age, 51 years) who had undergone both I-MRA and D-MRA underwent arthroscopic surgery. Both methods were performed in fat-saturated axial, coronal oblique, and sagittal oblique T1-weighted sequences, as well as axial and coronal oblique T2-weighted sequences. Two radiologists independently and retrospectively evaluated two sets of MRA for the diagnosis of superior and anterior labral tears, subscapularis tendon (SSC), and supraspinatus-infraspinatus tendon (SSP-ISP) tears, and LHBT tears. With the arthroscopic finding as a gold standard, we analyzed statistical differences of sensitivities and specificities between two sets of MRA and inter-observer agreement was evaluated using the kappa value.
  
  
  RESULTS
  The sensitivity and specificity of I-MRA and D-MRA for reader 1 were 79/80% and 71/80%, respectively, for superior labral tears; 100/100% and 100/100%, respectively, for anterior labral tears; 64/75% and 64/100%, respectively, for SSC tears; 100/86% and 100/100%, respectively, for SSP-ISP tears; and 67/100% and 78/100%, respectively, for LHBT tears. Those of I-MRA and D-MRA for reader 2 were 86/80% and 71/100%, respectively, for superior labral tears; 100/83% and 100/100%, respectively, for anterior labral tears; 64/88% and 82/100%, respectively, for SSC tears; 92/86% and 100/100%, respectively, for SSP-ISP tears; and 78/90% and 89/100%, respectively, for LHBT tears. No significant differences were found between the methods. Inter-observer agreements were higher than moderate (kappa > 0.41) with both methods.
  
  
  CONCLUSIONS
  Based on a relatively small number of patients, no significant difference was detected between I-MRI and D-MRI with regard rotator cuff, labral, and LHBT tears.
authors.affiliation: Department of Radiology, Samsung Medical Center, School of Medicine, Sungkyunkwan University, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710, Republic of Korea.
authors.forename: Jee Young
authors.initials: JY
authors.lastname: Jung
authors.forename: Young Cheol
authors.initials: YC
authors.lastname: Yoon
authors.forename: Sang-Kyu
authors.initials: SK
authors.lastname: Yi
authors.forename: Jaechul
authors.initials: J
authors.lastname: Yoo
authors.forename: Bong-Keun
authors.initials: BK
authors.lastname: Choe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001175:Arthrography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000145:classification / Q000379:methods; D008297:Male; D008875:Middle Aged; D017006:Rotator Cuff / Q000473:pathology*; D000070636:Rotator Cuff Injuries; D012785:Shoulder Joint / Q000000981:diagnostic imaging*; D055815:Young Adult