title: 3-d high-frequency ultrasound improves the estimation of surface properties in degenerated cartilage.
abstract: High-frequency ultrasound (US) surface parameters are well known to be sensitive to degenerative changes in cartilage tissue, but estimates deteriorate if the sample is inclined. We propose 3-D US to precisely estimate the local surface and inclination. For this purpose, the most common ultrasonic surface parameters ultrasound roughness index and integrated reflection coefficient were extended to 2-D surface measurements. Tissue-mimicking phantoms and human cartilage samples with varying degrees of degeneration were measured using a 40-MHz transducer. Characteristic inclination dependencies of the parameters aided in the distinction between specular reflected or backscattered signal origins and allowed a restriction to suitable local inclinations. In the application to cartilage, comparisons with histologic grading (structural Mankin-score) depicted a statistically significant (p < 0.05) increase of US roughness index for scores larger than 0 and decrease of integrated reflection coefficient for scores larger than 1. The presented findings will increase the reliability of ultrasonic surface parameters and can in principal be applied in vivo.
authors: Julius Wolff Institute and Berlin-Brandenburg School for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Germany.
authors: M
authors: M
authors: Schöne
authors: N
authors: N
authors: Männicke
authors: M
authors: M
authors: Gottwald
authors: F
authors: F
authors: Göbel
authors: K
authors: K
authors: Raum
mesh_terms: D000465:Algorithms; D002358:Cartilage, Articular / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D010003:Osteoarthritis / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*