title: Rotator cuff tears: should abduction and external rotation (ABER) positioning be performed before image acquisition? A CT arthrography study.
abstract: OBJECTIVE
  To evaluate the impact of abduction and external rotation (ABER) positioning performed before image acquisition on the assessment of rotator cuff tears.
  
  
  METHODS
  Twenty-seven consecutive patients with clinically suspected rotator cuff tears underwent an initial CT arthrogram of the shoulder in neutral position, immediately followed by temporary ABER positioning, before a second CT acquisition in neutral position. Two observers blinded to potential pre-procedure ABER positioning independently analysed the randomly distributed images. Lesions were classified into partial-thickness (PT) and full-thickness (FT) tear subtypes. Lesion detection and measurements of pre- and post-ABER studies were compared.
  
  
  RESULTS
  We found no influence of pre-test ABER positioning on FT detection or measurements. Every PT detected on pre-ABER study was also detected on post-ABER study (28/28 for reader 1, and 32/32 for reader 2). Seven and eight additional PT were found by readers 1 and 2, respectively, on post-ABER study. Lesion size increased after ABER in terms of area (P < 0.001 for both readers) and Ellman's grade (P = 0.02 and 0.002 for reader 1 and 2, respectively).
  
  
  CONCLUSIONS
  ABER positioning before CT is associated with improved delineation of partial tears, a higher number of detected tears and modification of treatment planning.
authors.affiliation: Unité d'imagerie thoracique et cardiovasculaire, Hopital cardiologique du Haut-Lévêque, CHU Bordeaux, Pessac, France. hcochet@wanadoo.fr
authors.forename: Hubert
authors.initials: H
authors.lastname: Cochet
authors.forename: Stephane
authors.initials: S
authors.lastname: Couderc
authors.forename: Eric
authors.initials: E
authors.lastname: Pelé
authors.forename: Nicolas
authors.initials: N
authors.lastname: Amoretti
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Moreau-Durieux
authors.forename: Olivier
authors.initials: O
authors.lastname: Hauger
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D006801:Humans; D007485:Ioxaglic Acid; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012399:Rotation; D017006:Rotator Cuff / Q000000981:diagnostic imaging*; D000070636:Rotator Cuff Injuries; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007485:Ioxaglic Acid