title: Quantitative Sonographic Assessment of the Quadriceps Femoris Muscle in Healthy Japanese Adults.
abstract: OBJECTIVE
  The aim of this study was to evaluate the relationships among aging, muscle strength, and image feature analysis of the quadriceps femoris muscle and to evaluate the relationship between aging, muscle strength, and sonographic findings.
  
  
  METHODS
  One hundred forty-five healthy volunteers participated in the study. The participants were classified into 6 groups on the basis of sex and age. To assess muscle quality, texture analysis was defined with the following parameters: mean, skewness, kurtosis, inverse difference moment, sum of entropy, and angular second moment. The knee extension force in the sitting position and thickness of the quadriceps femoris muscle were also measured.
  
  
  RESULTS
  The quadriceps femoris thickness, skewness, kurtosis, inverse difference moment, angular second moment, and muscle strength were significantly decreased in elderly participants versus those in the younger and middle-aged groups (P < .05). In contrast, the mean and sum of entropy were significantly decreased in the younger group compared with the middle-aged and elderly groups.
  
  
  CONCLUSIONS
  Sonography has the capacity to quantitatively assess muscular morphologic changes due to aging and could be a valuable tool for early detection of musculoskeletal disorders.
authors.affiliation: Division of Clinical Laboratory, Gifu University Hospital, Gifu, Japan.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Intelligent Image Information, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Murakami
authors.affiliation: Faculty of Education, Gifu University, Gifu, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Fukuoka
authors.affiliation: Department of Orthopedic Surgery, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Terabayashi
authors.affiliation: Sports Medicine and Sports Science , Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Sohee
authors.initials: S
authors.lastname: Shin
authors.affiliation: Sports Medicine and Sports Science , Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Yabumoto
authors.affiliation: Division of Clinical Laboratory, Gifu University Hospital, Gifu, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ito
authors.affiliation: Department of Intelligent Image Information, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujita
authors.affiliation: Sports Medicine and Sports Science , Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Matsuoka
authors.affiliation: Division of Clinical Laboratory, Gifu University Hospital, Gifu, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Seishima
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology / Q000502:physiology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007564:Japan / Q000453:epidemiology; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000502:physiology; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D015588:Observer Variation; D052097:Quadriceps Muscle / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012727:Sex Characteristics; D014463:Ultrasonography / Q000379:methods*
keywords: knee extension strength; musculoskeletal disorders; musculoskeletal ultrasound; sonography; texture analysis