Evaluation of Knee Cartilage Thickness: A Comparison between Ultrasound and Magnetic Resonance Imaging Methods

• Published in: The knee Vol. 24; no. 2; pp. 217 - 223
• Main Authors: Schmitz, Randy J, Wang, Hsin-Min, Polprasert, Daniel R, Kraft, Robert A, Pietrosimone, Brian G
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2017; Elsevier Limited
• Subjects: Body Weights and Measures; Cartilage diseases; Cartilage, Articular - diagnostic imaging; Cartilage, Articular - pathology; Clinical assessment; Female; Femur; Femur - diagnostic imaging; Femur - pathology; Healthy Volunteers; Humans; Knee; Knee Joint - diagnostic imaging; Knee Joint - pathology; Magnetic Resonance Imaging; Male; Medial femur; NMR; Nuclear magnetic resonance; Orthopedics; Osteoarthritis; Sheep; Skin & tissue grafts; Ultrasonography; Ultrasound; Young Adult; Medial Femur; Osteoarthritis; Clinical Assessment; Medial femur; Clinical assessment
• ISSN: 0968-0160; 1873-5800
• DOI: 10.1016/j.knee.2016.10.004

Abstract Background Establishing clinically accessible measures of cartilage health is critical for assessing effectiveness of protocols to reduce risk of osteoarthritis (OA) development and progression. Cartilage thickness is one important measure in describing both OA development and progression. The objective was to determine the relationship between ultrasound and MRI measures of cartilage thickness in the medial femoral condyle. Methods Mean cartilage thicknesses of the left medial femoral cartilage were measured via T1 weighted MRI and ultrasound imaging from transverse, anterior, middle, and posterior medial femoral regions in ten healthy females (1.66 ± 0.08 m, 59.5 ± 8.3 kg, 21.6 ± 1.4 yrs) and nine healthy males (1.80 ± 0.08 m, 79.1 ± 6.2 kg, 21.7 ± 1.5 yrs). Pearson correlations examined relationships between MRI and ultrasound measures. Bland–Altman plots evaluated agreement between the imaging modalities. Results Transverse ultrasound thickness measures were significantly positively correlated with MRI middle (r = .67, P ≤ .05) and posterior thicknesses(r = .49, P ≤ .05) while the middle and posterior longitudinal ultrasound measures were significantly correlated to their respective MRI regions (r = .67, P ≤ .05 & r = .59 P ≤ .05, respectively). There was poor absolute agreement between correlated measures with ultrasound thickness measures being between 1.9–2.8 mm smaller than MRI measures. Conclusions These results suggest that ultrasound may be a viable clinical tool to assess relative cartilage thickness in the middle and posterior medial femoral regions. However, the absolute validity of the ultrasound measure is called into question due to the larger MRI-based thickness measures. Level of Evidence Level IV.