Texture analysis of cartilage T2 maps: individuals with risk factors for OA have higher and more heterogeneous knee cartilage MR T2 compared to normal controls - data from the osteoarthritis initiative

Abstract

IntroductionThe goals of this study were (i) to compare the prevalence of focal knee abnormalities, the mean cartilage T2 relaxation time, and the spatial distribution of cartilage magnetic resonance (MR) T2 relaxation times between subjects with and without risk factors for Osteoarthritis (OA), (ii) to determine the relationship between MR cartilage T2 parameters, age and cartilage morphology as determined with whole-organ magnetic resonance imaging scores (WORMS) and (iii) to assess the reproducibility of WORMS scoring and T2 relaxation time measurements including the mean and grey level co-occurrence matrix (GLCM) texture parameters.MethodsSubjects with risk factors for OA (n = 92) and healthy controls (n = 53) were randomly selected from the Osteoarthritis Initiative (OAI) incidence and control cohorts, respectively. The specific inclusion criteria for this study were (1) age range 45-55 years, (2) body mass index (BMI) of 19-27 kg/m2, (3) Western Ontario and McMaster University (WOMAC) pain score of zero and (4) Kellgren Lawrence (KL) score of zero at baseline. 3.0 Tesla MR images of the right knee were analyzed using morphological gradings of cartilage, bone marrow and menisci (WORMS) as well as compartment specific cartilage T2 mean and heterogeneity. Regression models adjusted for age, gender, and BMI were used to determine the difference in cartilage parameters between groups.ResultsWhile there was no significant difference in the prevalence of knee abnormalities (cartilage lesions, bone marrow lesions, meniscus lesions) between controls and subjects at risk for OA, T2 parameters (mean T2, GLCM contrast, and GLCM variance) were significantly elevated in those at risk for OA. Additionally, a positive significant association between cartilage WORMS score and cartilage T2 parameters was evident.ConclusionsOverall, this study demonstrated that subjects at risk for OA have both higher and more heterogeneous cartilage T2 values than controls, and that T2 parameters are associated with morphologic degeneration.

Probing articular cartilage damage and disease by quantitative magnetic resonance imaging

“…T 2 patterns also differ between normal cartilage and cartilage with pre-radiographic and radiographic damage [87]. Patients with elevated risk factors for OA exhibit greater T 2 values and heterogeneity than controls with similar preradiographic cartilage damage, possibly indicating a higher degree of extracellular matrix breakdown [88]. T 2 mapping can indicate changes associated with cartilage damage, but the interpretation of these changes must consider the limitations of this technique.…”

Association of diabetes mellitus and biochemical knee cartilage composition assessed by T2 relaxation time measurements: Data from the osteoarthritis initiative

“…Due to a large number of outcome parameters, analyses were split into the following categories based on previously published analyses 16,28,35,36 …”

“…18 In addition, cartilage GLCM texture analysis was performed to evaluate the spatial distribution of cartilage T 2 values within each cartilage compartment, reflecting heterogeneity of T 2 values throughout the cartilage matrix, as a measure for cartilage degeneration. 16,17,[28][29][30] Based on our previous work, three GLCM texture parameters were included in the analysis: contrast (contrast group), entropy (orderliness group), and variance (statistics group). 16,30 These additional analyses were performed and interpreted as described previously.…”

“…16,17,[28][29][30] Based on our previous work, three GLCM texture parameters were included in the analysis: contrast (contrast group), entropy (orderliness group), and variance (statistics group). 16,30 These additional analyses were performed and interpreted as described previously. 30 Morphological MR sequences from both groups were reviewed on a picture archiving communication system (PACS) workstations (Agfa, Ridgefield Park, NJ) by two radiologists (N.C. and A.S.G.…”

“…Texture analysis using gray-level co-occurrence matrices (GLCM) has shown to allow early detection of compositional changes of cartilage in subjects at risk for OA, before radiographic evidence for OA is present, by providing additional data on the T 2 value distribution of neighboring pixels. 16,17 Laminar analysis, in which cartilage is separated into a deep bone and superficial articular layer, may also visualize early laminar disruption within cartilage when overall T 2 does not yet reveal changes of cartilage composition. 18 The purpose of this study was to investigate the relationship between DM and cartilage composition to determine if an imaging biomarker could identify biochemical cartilage abnormalities in DM patients.…”