MRI evaluation of articular cartilage in patients with juvenile osteochondritis dissecans (JOCD) using T2∗ mapping at 3T

Abstract

Objective: Evaluate articular cartilage by magnetic resonance imaging (MRI) T2* mapping within the distal femur and proximal tibia in adolescents with juvenile osteochondritis dissecans (JOCD). Design: JOCD imaging studies acquired between August 2011 and February 2019 with clinical and T2* mapping MRI knee images were retrospectively collected and analyzed for 31 participants (9F/22M, 15.0 ± 3.8 years old) with JOCD lesions in the medial femoral condyle (MFC). In total, N ¼ 32 knees with JOCD lesions and N ¼ 14 control knees were assessed. Mean T2* values in four articular cartilage regionsof-interest (MFC, lateral femoral condyle (LFC), medial tibia (MT), and lateral tibia (LT)) and lesion volume were measured and analyzed using Wilcoxon-rank-sum tests and Spearman correlation coefficients (R). Results: Mean ± standard error T2* differences observed between the lesion-sided MFC and the LFC in JOCD-affected knees (28.5 ± 0.9 95% confidence interval [26.8, 30.3] vs 26.3 ± 0.7 [24.8, 27.7] ms, P ¼ 0.088) and between the affected-and control-knee MFC (28.5 ± 0.9 [26.8, 30.3] vs 28.5 ± 0.6 [27.1, 29.9] ms, P ¼ 0.719) were nonsignificant. T2* was significantly increased in the lesion-sided MT vs the LT for the JOCD-affected knees (21.5 ± 0.7 [20.1, 22.9] vs 18.0 ± 0.7 [16.5, 19.5] ms, P ¼ 0.002), but this same difference was also observed between the MT and LT in control knees (21.0 ± 0.6 [19.7, 22.3] vs 18.1 ± 1.1 [15.8, 20.4] ms, P ¼ 0.037). There was no significant T2* difference between the affected-and controlknee MT (21.5 ± 0.7 [20.1, 22.9] vs 21.0 ± 0.6 [19.7, 22.3] ms, P ¼ 0.905). T2* within the lesion-sided MFC was not correlated with patient age (R ¼ 0.20, P ¼ 0.28) or lesion volume (R ¼ 0.06, P ¼ 0.75). T2* values were slightly increased near lesions in later-stage JOCD subjects but without statistical significance. Conclusions: T2* relaxations times were not significantly different from control sites in the articular cartilage overlying JOCD lesions in the MFC or adjacent MT cartilage in early-stage JOCD.

Compositional evaluation of lesion and parent bone in patients with juvenile osteochondritis dissecans of the knee using T2* mapping

“…We found a progressively decreasing T 2 * values with increasing JOCD stage in progeny lesion and interface which is due to the gradual ossification of lesion. The T 2 * of progeny lesion at stage I was high and similar to previously reported T 2 * of articular cartilage 23,24 and fibrocartilage, 25 while the progenyT 2 * at stage IV was low and similar to the T 2 * of trabecular bone. [30][31][32] These results emphasize the role of progressive ossification in lesion healing in the natural history of JOCD, 2,7-9,18 and confirm the previously proposed JOCD staging system based on qualitative evaluation of osseous tissues on short TE GRE images with CT-like contrast.…”

“…T 2 * values reflect the interactions between the magnetic moments of water and the surrounding macromolecules in the given tissue and therefore provides indirect measurement of tissue microstructure and composition. 21,22 Quantitative T 2 * mapping has been successfully used to evaluate microstructure and composition of the articular cartilage, 23,24 fibrocartilage, 25 and trabecular bone. [26][27][28][29] Previously reported T 2 * values in cartilage (~23 ms) 23,24 and fibrocartilage (~19 ms) 25 are much higher compared to T 2 * in trabecular bone (~4 ms), [30][31][32] T 2 * mapping should therefore allow differentiation between cartilaginous and osseous regions within JOCD lesions.…”

“…21,22 Quantitative T 2 * mapping has been successfully used to evaluate microstructure and composition of the articular cartilage, 23,24 fibrocartilage, 25 and trabecular bone. [26][27][28][29] Previously reported T 2 * values in cartilage (~23 ms) 23,24 and fibrocartilage (~19 ms) 25 are much higher compared to T 2 * in trabecular bone (~4 ms), [30][31][32] T 2 * mapping should therefore allow differentiation between cartilaginous and osseous regions within JOCD lesions. Furthermore, magnetic susceptibility differences between bone trabeculae and marrow impose static field inhomogeneities and causes shortening of T 2 * values.…”

“…Considering the difference in T 2 * values between articular cartilage 23,24 and trabecular bone [26][27][28][29] reported in previous studies, the goal of the present study was to determine if T 2 * mapping allows noninvasive, quantitative assessment of all lesion tissues (i.e., cartilaginous and osseous) and evaluation of their structure and composition in JOCD patients. Therefore, we retrospectively evaluated participants with JOCD lesions in distal femoral condyle to assess ability of quantitative T 2 * mapping to detect differences in tissue composition between: (i) different regions within JOCD lesions, (ii) different JOCD stages, and (iii) between stable and unstable JOCD lesions.…”

A method for labelling lesions for machine learning and some new observations on osteochondrosis in computed tomographic scans of four pig joints

“…We intend to pursue this by analysing the shape and dimensions of the current CT lesion masks further. The metabolism of medial versus lateral femoral chondrocytes could also be studied [ 37 ], or lesions could be compared using three-dimensional modalities that enable simultaneous visualisation of vessel configuration, osteochondrosis latens and manifesta lesions, such as second harmonics generation microscopy [ 28 ], or various magnetic resonance imaging sequences [ 38 , 39 ].…”