title: Reliability of magnetic resonance imaging assessment of rotator cuff: the ROW study.
abstract: BACKGROUND
  Physiatrists encounter patients with rotator cuff disorders, and imaging is frequently an important component of their diagnostic assessment. However, there is a paucity of literature on the reliability of magnetic resonance imaging (MRI) assessment between shoulder specialists and musculoskeletal radiologists.
  
  
  OBJECTIVE
  We assessed inter- and intrarater reliability of MRI characteristics of the rotator cuff.
  
  
  METHODS
  Cross-sectional secondary analyses in a prospective cohort study.
  
  
  METHODS
  Academic tertiary care centers.
  
  
  METHODS
  Subjects with shoulder pain were recruited from orthopedic and physiatry clinics.
  
  
  METHODS
  Two shoulder-fellowship-trained physicians (a physiatrist and a shoulder surgeon) jointly performed a blinded composite MRI review by consensus of 31 subjects with shoulder pain. Subsequently, MRI was reviewed by one fellowship-trained musculoskeletal radiologist.
  
  
  METHODS
  We calculated the Cohen kappa coefficients and percentage agreement among the 2 reviews (composite review of 2 shoulder specialists versus that of the musculoskeletal radiologist). Intrarater reliability was assessed among the shoulder specialists by performing a repeated blinded composite MRI review. In addition to this repeated composite review, only one of the physiatry shoulder specialists performed an additional review.
  
  
  RESULTS
  Interrater reliability (shoulder specialists versus musculoskeletal radiologist) was substantial for the presence or absence of tear (kappa 0.90 [95% confidence interval {CI}, 0.72-1.00]), tear thickness (kappa 0.84 [95% CI, 0.70-0.99]), longitudinal size of tear (kappa 0.75 [95% CI, 0.44-1.00]), fatty infiltration (kappa 0.62 [95% CI, 0.45-0.79]), and muscle atrophy (kappa 0.68 [95% CI, 0.50-0.86]). There was only fair interrater reliability of the transverse size of tear (kappa 0.20 [95% CI, 0.00-0.51]). The kappa for intrarater reliability was high for tear thickness (0.88 [95% CI, 0.72-1.00]), longitudinal tear size (0.61 [95% CI, 0.22-0.99]), fatty infiltration (0.89 [95% CI, 0.80,-0.98]), and muscle atrophy (0.87 [95% CI, 0.76-0.98]). Intrarater reliability for the individual shoulder specialist was similar to that of the composite reviews.
  
  
  CONCLUSIONS
  There was high interrater and intrarater reliability for most findings on shoulder MRI. Analysis of our data supports the reliability of MRI assessment by shoulder specialists for rotator cuff disorders.
authors.affiliation: Departments of Physical Medicine and Rehabilitation, and Orthopaedics, Vanderbilt University Medical Center, Nashville, TN; Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital and Harvard Medical School, Boston, MA; Department of Orthopaedic Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA(∗). Electronic address: nitin.jain@vanderbilt.edu.
authors.forename: Nitin B
authors.initials: NB
authors.lastname: Jain
authors.affiliation: Department of Orthopaedic Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA†
authors.forename: Jamie
authors.initials: J
authors.lastname: Collins
authors.affiliation: Department of Radiology, New England Baptist Hospital, Boston, MA‡
authors.forename: Joel S
authors.initials: JS
authors.lastname: Newman
authors.affiliation: Department of Orthopaedic Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA§
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Katz
authors.affiliation: Department of Orthopaedic Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Department of Biostatistics, Boston University School of Public Health, Boston, MA||
authors.forename: Elena
authors.initials: E
authors.lastname: Losina
authors.affiliation: Department of Orthopaedic Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA¶
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Higgins
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D000070636:Rotator Cuff Injuries; D020069:Shoulder Pain / Q000209:etiology / Q000473:pathology*; D052256:Tendinopathy / Q000150:complications / Q000175:diagnosis*