title: Theoretical prediction of ultrasound elastography for detection of early osteoarthritis.
abstract: Ultrasound elastography could be used as a new noninvasive technique for detecting early osteoarthritis. As the first critical step, this study theoretically predicted the excitation power and the measurement errors in detecting cartilage detect. A finite element model was used to simulate wave propagation of elastography in the cartilage. The wave was produced by a force F, and the wave speed C was calculated. The normal cartilage model was used to define the relationship between the wave speed and elastic modulus. Various stiffness values were simulated. F = 10 N with a duration of 0.5 ms was required for having measurable deformation (10 μm) at the distal site. The deformation had a significant rise when the wave crossed the defect. The relationship between the wave speed and elastic parameters was found as C = 1.57 × (E)/(2 × ρ(1+μ)))(1/2), where E was the elastic modulus, μ was Poisson's ratio, and ρ was the density. For the simulated defect with an elastic modulus of 7 MPa which was slightly stiffer than the normal cartilage, the measurement error was 0.1 MPa. The results suggested that, given the simulated conditions, this new technique could be used to detect the defect in early osteoarthritis.
authors.affiliation: Orthopaedic Institute, The 1st Affiliated Hospital Soochow University, 708 Renmin Road, Suzhou, Jiangsu 215007, China ; Department of Orthopedics of the 1st Affiliated Hospital Soochow University, 708 Renmin Road, Suzhou, Jiangsu 215007, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.forename: Shigao
authors.initials: S
authors.lastname: Chen
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Yang
authors.forename: Zong-Ping
authors.initials: ZP
authors.lastname: Luo
mesh_terms: D002358:Cartilage, Articular / Q000000981:diagnostic imaging; D003198:Computer Simulation; D042241:Early Diagnosis; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods* / Q000706:statistics & numerical data; D020342:Finite Element Analysis; D006801:Humans; D008954:Models, Biological; D010003:Osteoarthritis / Q000175:diagnosis / Q000000981:diagnostic imaging*; D016012:Poisson Distribution