title: Analysis of Low-Field MRI Scanners for Evaluation of Shoulder Pathology Based on Arthroscopy.
abstract: BACKGROUND
  Many studies have compared the diagnostic capabilities of low-field magnetic resonance imaging (MRI) scanners to high-field MRI scanners; however, few have evaluated the low-field MRI diagnoses compared with intraoperative findings.
  
  
  OBJECTIVE
  To determine the accuracy and sensitivity of low-field MRI scanners in diagnosing lesions of the rotator cuff and glenoid labrum.
  
  
  METHODS
  Cohort study (diagnosis); Level of evidence, 3.
  
  
  METHODS
  Over a 2-year period, MRI examinations without intra-articular contrast were performed on 79 patients for shoulder pathologies using an in-office 0.2-T extremity scanner. The MRI examinations were read by board-certified, musculoskeletal fellowship-trained radiologists. All patients underwent shoulder arthroscopy performed by a single sports fellowship-trained orthopaedic surgeon within a mean time of 56 days (range, 8-188 days) after the MRI examination. The mean patient age was 54 years (range, 18-81 years). Operative notes from the shoulder arthroscopies were then retrospectively reviewed by a single blinded observer, and the intraoperative findings were compared with the MRI reports.
  
  
  RESULTS
  For partial-thickness rotator cuff tears, the sensitivity, specificity, positive predictive value, and negative predictive value were 85%, 89%, 79%, and 92%, respectively. For full-thickness rotator cuff tears, the respective values were 97%, 100%, 100%, and 98%. For anterior labral lesions, the values were 86%, 99%, 86%, and 99%, and for superior labral anterior-posterior (SLAP) lesions, the values were 20%, 100%, 100%, and 79%, respectively.
  
  
  CONCLUSIONS
  Low-field MRI is an accurate tool for evaluation of partial- and full-thickness rotator cuff tears; however, it is not effective in diagnosing SLAP lesions. More information is needed to properly assess its ability to diagnose anterior and posterior labral lesions.
authors.affiliation: Stetson Powell Orthopaedics and Sports Medicine, Burbank, California, USA.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Stetson Powell Orthopaedics and Sports Medicine, Burbank, California, USA.
authors.forename: Shane M
authors.initials: SM
authors.lastname: Davis
authors.affiliation: Stetson Powell Orthopaedics and Sports Medicine, Burbank, California, USA.
authors.forename: Claire
authors.initials: C
authors.lastname: McGroder
authors.affiliation: Stetson Powell Orthopaedics and Sports Medicine, Burbank, California, USA.
authors.forename: Shalen
authors.initials: S
authors.lastname: Kouk
authors.affiliation: Stetson Powell Orthopaedics and Sports Medicine, Burbank, California, USA.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Sung
authors.affiliation: Stetson Powell Orthopaedics and Sports Medicine, Burbank, California, USA.
authors.forename: William B
authors.initials: WB
authors.lastname: Stetson
authors.affiliation: Stetson Powell Orthopaedics and Sports Medicine, Burbank, California, USA.
authors.forename: Scott E
authors.initials: SE
authors.lastname: Powell
keywords: glenoid labrum; low-field MRI; rotator cuff