title: In vivo measurement of human achilles tendon morphology using freehand 3-D ultrasound.
abstract: This study investigated the accuracy of phantom volume and length measurements and the reliability of in vivo Achilles tendon (AT) volume, length and cross-sectional area measurements obtained using freehand 3-D ultrasound. Participants (n = 13) were scanned on consecutive days under active and passive loading conditions. In vivo AT length was evaluated using a two-point method and an approach that accounted for AT curvature (centroid method). Three-dimensional ultrasound provided accurate measures of phantom volume and length (mean difference = 0.05 mL and 0.2 mm, respectively) and reliable in vivo measures of AT volume, length and average cross-sectional area, with all intra-class correlations coefficients greater than 0.98. The mean minimally detectable changes for in vivo AT volume, two-point length and centroid length were 0.2 mL, 1.5 mm and 2.0 mm, respectively. Two-point AT length underestimated centroid AT length by 0.7 mm, suggesting that the effect of curvature on in vivo AT length is negligible.
authors.affiliation: School of Rehabilitation Sciences and Centre for Musculoskeletal Research, Griffith Health Institute, Griffith University, Southport, Queensland, Australia. Electronic address: s.obst@griffith.edu.au.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Obst
authors.forename: Richard
authors.initials: R
authors.lastname: Newsham-West
authors.forename: Rod S
authors.initials: RS
authors.lastname: Barrett
mesh_terms: D000125:Achilles Tendon / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000502:physiology; D000328:Adult; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008953:Models, Anatomic; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods
keywords: 3-D ultrasound; Cross-sectional area; Length; Tendon; Volume