title: The effects of aging on quantitative sonographic features of rotator cuff tendons.
abstract: OBJECTIVE
  Grayscale analysis is a practical, objective, and easy way to quantify echogenicity during ultrasonography. The purpose of the current study was to measure the changes in thickness and echogenicity that result from aging of the rotator cuff and long head of the biceps tendons.
  
  
  METHODS
  The study comprised 45 volunteers, aged between 20 and 84 years and without history of shoulder pain. Participants were divided into three groups: young, middle-aged, and old. All subjects underwent standard ultrasonography of both shoulders. Tendon thickness and tear were recorded, and images in both transverse and longitudinal scans were taken for grayscale analysis. To reduce the attenuation effect from skin and subcutaneous fat, we used the ratio of echogenicity of the tendon to that of the reference muscle and compared the tendon echogenicity among the different age groups. Sonographic findings were also correlated with age.
  
  
  RESULTS
  The supraspinatus tendon was significantly thicker in elderly participants and this was positively correlated with age. Moreover, the echogenicity ratio of the supraspinatus tendon decreased in the elderly group and showed a negative correlation with age. There was a higher prevalence of supraspinatus tendon tears in the older participants.
  
  
  CONCLUSIONS
  Our results indicate that supraspinatus tendons became thickened, hypoechogenic, and more likely to tear with age. The study presents a simple and useful method to investigate the echogenicity of the rotator cuff quantitatively.
authors.affiliation: Department of Physical Medicine & Rehabilitation, Chang Gung Memorial Hospital, Linkou, Taiwan.
authors.forename: Tung-Yang
authors.initials: TY
authors.lastname: Yu
authors.forename: Wen-Chung
authors.initials: WC
authors.lastname: Tsai
authors.forename: Ju-Wen
authors.initials: JW
authors.lastname: Cheng
authors.forename: Yun-Ming
authors.initials: YM
authors.lastname: Yang
authors.forename: Fang-Chen
authors.initials: FC
authors.lastname: Liang
authors.forename: Chien-Hung
authors.initials: CH
authors.lastname: Chen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015331:Cohort Studies; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors; D017006:Rotator Cuff / Q000000981:diagnostic imaging* / Q000473:pathology; D012680:Sensitivity and Specificity; D020069:Shoulder Pain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013710:Tendons / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography; D055815:Young Adult