Articular cartilage degeneration classification by means of high-frequency ultrasound

• Published in: Osteoarthritis and cartilage Vol. 22; no. 10; pp. 1577 - 1582
• Main Authors: Männicke, N, Schöne, M, Oelze, M, Raum, K
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-10-2014
• Subjects: Backscatter; Cartilage; Cartilage Diseases - diagnostic imaging; Cartilage Diseases - etiology; Cartilage Diseases - pathology; Cartilage, Articular - diagnostic imaging; Cartilage, Articular - pathology; Case-Control Studies; Classification; Degeneration; Humans; Logistic Models; Osteoarthritis, Knee - complications; Osteoarthritis, Knee - diagnostic imaging; Osteoarthrosis; Rheumatology; ROC Curve; Ultrasonography; Ultrasound biomicroscopy; Cartilage; Osteoarthrosis; Degeneration; Classification; Backscatter; Ultrasound biomicroscopy
• ISSN: 1063-4584; 1522-9653
• DOI: 10.1016/j.joca.2014.06.019

Summary Context To date only single ultrasound parameters were regarded in statistical analyses to characterize osteoarthritic changes in articular cartilage and the potential benefit of using parameter combinations for characterization remains unclear. Objective Therefore, the aim of this work was to utilize feature selection and classification of a Mankin subset score (i.e., cartilage surface and cell sub-scores) using ultrasound-based parameter pairs and investigate both classification accuracy and the sensitivity towards different degeneration stages. Design 40 punch biopsies of human cartilage were previously scanned ex vivo with a 40-MHz transducer. Ultrasound-based surface parameters, as well as backscatter and envelope statistics parameters were available. Logistic regression was performed with each unique US parameter pair as predictor and different degeneration stages as response variables. The best ultrasound-based parameter pair for each Mankin subset score value was assessed by highest classification accuracy and utilized in receiver operating characteristics (ROC) analysis. Results The classifications discriminating between early degenerations yielded area under the ROC curve (AUC) values of 0.94–0.99 (mean ± SD: 0.97 ± 0.03). In contrast, classifications among higher Mankin subset scores resulted in lower AUC values: 0.75–0.91 (mean ± SD: 0.84 ± 0.08). Variable sensitivities of the different ultrasound features were observed with respect to different degeneration stages. Conclusions Our results strongly suggest that combinations of high-frequency ultrasound-based parameters exhibit potential to characterize different, particularly very early, degeneration stages of hyaline cartilage. Variable sensitivities towards different degeneration stages suggest that a concurrent estimation of multiple ultrasound-based parameters is diagnostically valuable. In-vivo application of the present findings is conceivable in both minimally invasive arthroscopic ultrasound and high-frequency transcutaneous ultrasound.