title: Diagnosis of small partial-thickness rotator cuff tears using vibro-acoustography.
abstract: OBJECTIVE
  Vibro-acoustography is a new imaging technique based on the dynamic radiation force of ultrasound. The purpose of this study was to apply this new imaging technique to the diagnosis of small partial-thickness rotator cuff tears and to determine how small of tears could be detected with this imaging technique.
  
  
  METHODS
  Seven supraspinatus tendons excised from embalmed cadavers were used. Three different sizes of partial-thickness bursal-sided tears (1, 3, and 5 mm(3)) were created in each specimen. The intersection of two co-focused ultrasound beams of slightly different frequency was swept across the intended imaging area. The acoustic emission data were collected and used to form and display a vibro-acoustography image of the tendon. Vibro-acoustography images were read by two orthopedic surgeons.
  
  
  RESULTS
  The rotator cuff tear could be detected by vibro-acoustography in all specimens. The diagnostic concordance rate was 90.5 % and the kappa coefficient value was 0.88, which resulted in a high concordance. The diagnostic concordance rate for the 1 mm tear was 71.3 %, which was low concordance (κ = 0.481), whereas that for the 3 and 5 mm tears was 100 %.
  
  
  CONCLUSIONS
  We were able to detect a 3-mm tear by using vibro-acoustography. There is a possibility that this new imaging technique could become a useful imaging tool for the diagnosis of small partial-thickness rotator cuff tears.
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN, USA.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Randall R
authors.initials: RR
authors.lastname: Kinnick
authors.affiliation: Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Fatemi
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN, USA.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Muraki
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Sperling
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Scott P
authors.initials: SP
authors.lastname: Steinmann
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Cofield
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Itoi
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN, USA. an@mayo.edu.
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D054459:Elasticity Imaging Techniques; D006801:Humans; D008875:Middle Aged; D017006:Rotator Cuff / Q000000981:diagnostic imaging*; D000070636:Rotator Cuff Injuries
keywords: Diagnosis; Rotator cuff tear; Small tear; Vibro-acoustography