title: Reporting rotator cuff tears on magnetic resonance arthrography using the Snyder's arthroscopic classification.
abstract: OBJECTIVE
  To determine diagnostic performance of magnetic resonance arthrography (MRA) in evaluating rotator cuff tears (RCTs) using Snyder's classification for reporting.
  
  
  METHODS
  One hundred and twenty-six patients (64 males, 62 females; median age 55 years) underwent shoulder MRA and arthroscopy, which represented our reference standard. Surgical arthroscopic reports were reviewed and the reported Snyder's classification was recorded. MRA examinations were evaluated by two independent radiologists (14 and 5 years' experience) using Snyder's classification system, blinded to arthroscopy. Agreement between arthroscopy and MRA on partial- and full-thickness tears was calculated, first regardless of their extent. Then, analysis took into account also the extent of the tear. Interobserver agreement was also calculated the quadratically-weighted Cohen kappa statistics.
  
  
  RESULTS
  On arthroscopy, 71/126 patients (56%) had a full-thickness RCT. The remaining 55/126 patients (44%) had a partial-thickness RCT. Regardless of tear extent, out of 71 patients with arthroscopically-confirmed full-thickness RCTs, 66 (93%) were correctly scored by both readers. All 55 patients with arthroscopic diagnosis of partial-thickness RCT were correctly assigned as having a partial-thickness RCT at MRA by both readers. Interobserver reproducibility analysis showed total agreement between the two readers in distinguishing partial-thickness from full-thickness RCTs, regardless of tear extent (k = 1.000). With regard to tear extent, in patients in whom a complete tear was correctly diagnosed, correct tear extent was detected in 61/66 cases (92%); in the remaining 5/66 cases (8%), tear extent was underestimated. Agreement was k = 0.955. Interobserver agreement was total (k = 1.000).
  
  
  CONCLUSIONS
  MRA shows high diagnostic accuracy and reproducibility in evaluating RCTs using the Snyder's classification for reporting. Snyder's classification may be adopted for routine reporting of MRA.
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Aliprandi
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Carmelo
authors.initials: C
authors.lastname: Messina
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Arrigoni
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Bandirali
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Di Leo
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Longo
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Sandro
authors.initials: S
authors.lastname: Magnani
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Mattiuz
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Randelli
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Silvana
authors.initials: S
authors.lastname: Sdao
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sardanelli
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Luca Maria
authors.initials: LM
authors.lastname: Sconfienza
authors.affiliation: Alberto Aliprandi, Michele Bandirali, Giovanni Di Leo, Silvana Sdao, Francesco Sardanelli, Servizio di Radiologia, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Randelli
keywords: Arthrography; Arthroscopy; Magnetic resonance imaging; Rotator cuff tear; Shoulder; Supraspinatus tendon