Delayed gadolinium-enhanced MRI of meniscus (dGEMRIM) and cartilage (dGEMRIC) in healthy knees and in knees with different stages of meniscus pathology

Background: Lesions in the meniscus are risk factors for developing knee osteoarthritis (OA), not least because of the role of the meniscus in the pathological progression of OA. Delayed gadolinium enhanced MRI of cartilage (dGEMRIC) has extensively been used to identify pre-radiographic cartilage changes in OA. In contrast, its counterpart with regard to examination of the meniscus, gadolinium enhanced MRI of meniscus (dGEMRIM), has been less utilized. In this study we use 3D dGEMRIM in patients with meniscus lesions and compare them with previous results of healthy individuals. Methods: Eighteen subjects with MRI-verified posteromedial meniscus lesions and 12 healthy subjects with non-injured and non-symptomatic knee joints, together 30 volunteers, were examined using 3D Look-Locker sequence after intravenous injection of Gd-DTPA2- (0.2 mmol/kg body weight). Relaxation time (T1) was measured in the posterior meniscus and femoral cartilage before and 60, 90, 120 and 180 min after injection. Relaxation rate (R1 = 1/T1) and change in relaxation rate (ΔR1) were calculated. For statistical analyses, Student's t-test and Analysis of Variance (ANOVA) were used. Results: The pre-contrast diagnostic MRI identified two sub-cohorts in the 18 patients with regard to meniscus injury: 1) 11 subjects with MRI verified pathological intrameniscal changes (grade 2) in the posteromedial meniscus only and no obvious cartilage changes. The lateral meniscus showed no pathology. 2) 7 subjects with MRI verified pathological rupture (grade 3) of the posteromedial meniscus and pathological changes in the lateral meniscus and/or medial and lateral joint cartilage. Comparisons of pathological and healthy posteromedial meniscus revealed opposite patterns in both T1Gd and ΔR1 values between pathological meniscus grade 2 and grade 3. The concentration of the contrast agent was lower than in healthy meniscus in grade 2 lesions (p = 0.046) but tended to increase in grade 3 lesions (p = 0.110). Maximum concentration of contrast agent was reached after 180 min in both cartilage and menisci (except for grade 3 menisci where the maximum concentration was reached after 90 min). Conclusion: dGEMRIM and dGEMRIC may be feasible to combine in vivo, preferably with one examination before and one 2 h after contrast injection. Possible different dGEMRIM patterns at different stages of meniscus lesions must be taken into account when evaluating meniscus pathology

T2 mapping and post-contrast T1 (dGEMRIC) of the patellar cartilage:12-year follow-up after patellar stabilizing surgery in childhood

Abstract Background: Cartilage degeneration has been reported after recurrent patellar dislocation. However, effects of surgical stabilization in childhood have not yet been described. Purpose: To examine the cartilage quality in very young adults operated with a patellar stabilizing procedure due to recurrent patellar dislocation in childhood, and evaluate if cartilage quality correlates with clinical parameters and patient-reported outcomes. Material and Methods: Seventeen patients were investigated ≥ 5 years (mean = 11.6 years) after patellar stabilizing surgery in childhood. Pre-contrast T2 relaxation times were analyzed in four superficial and four deep patellar cartilage regions of both knees. Two hours after 0.2 mM/kg Gd-DTPA² i.v., post-contrast T1 (T1(Gd)) was analyzed in the same regions. Patient-reported outcomes (KOOS, Kujala, and Tegner scores) and recurrence rates were evaluated. Results: Comparing operated to healthy side, neither T2 nor dGEMRIC differed between the operated and the reference knee regarding the superficial half of the cartilage. In the deep half of the cartilage, T1(Gd) was shorter in the central part of the cartilage, whereas T2 was longer medially (P < 0.05). A low score in the KOOS subscales Symptom and Sports and Recreation, was correlated to the degenerative changes detected by T1(Gd) (r = 0.5, P = 0.041). Conclusion: In general, our findings demonstrate good cartilage quality 12 years after patellar stabilizing surgery during childhood. The subtle changes in T2 and T1(Gd) in the deep cartilage layer may be a result of altered biomechanics, although very early degenerative changes cannot be excluded. The short T1(Gd) centrally may reflect lower glycosaminoglycan content, whereas the increase in T2 medially indicates increased cartilage hydration

Delayed gadolinium-enhanced MRI of meniscus (dGEMRIM) and cartilage (dGEMRIC) in healthy knees and in knees with different stages of meniscus pathology

Abstract Background: Lesions in the meniscus are risk factors for developing knee osteoarthritis (OA), not least because of the role of the meniscus in the pathological progression of OA. Delayed gadolinium enhanced MRI of cartilage (dGEMRIC) has extensively been used to identify pre-radiographic cartilage changes in OA. In contrast, its counterpart with regard to examination of the meniscus, gadolinium enhanced MRI of meniscus (dGEMRIM), has been less utilized. In this study we use 3D dGEMRIM in patients with meniscus lesions and compare them with previous results of healthy individuals. Methods: Eighteen subjects with MRI-verified posteromedial meniscus lesions and 12 healthy subjects with non-injured and non-symptomatic knee joints, together 30 volunteers, were examined using 3D Look-Locker sequence after intravenous injection of Gd-DTPA²⁻ (0.2 mmol/kg body weight). Relaxation time (T1) was measured in the posterior meniscus and femoral cartilage before and 60, 90, 120 and 180 min after injection. Relaxation rate (R1 = 1/T1) and change in relaxation rate (ΔR1) were calculated. For statistical analyses, Student’s t-test and Analysis of Variance (ANOVA) were used. Results: The pre-contrast diagnostic MRI identified two sub-cohorts in the 18 patients with regard to meniscus injury: 1) 11 subjects with MRI verified pathological intrameniscal changes (grade 2) in the posteromedial meniscus only and no obvious cartilage changes. The lateral meniscus showed no pathology. 2) 7 subjects with MRI verified pathological rupture (grade 3) of the posteromedial meniscus and pathological changes in the lateral meniscus and/or medial and lateral joint cartilage. Comparisons of pathological and healthy posteromedial meniscus revealed opposite patterns in both T1Gd and ΔR1 values between pathological meniscus grade 2 and grade 3. The concentration of the contrast agent was lower than in healthy meniscus in grade 2 lesions (p = 0.046) but tended to increase in grade 3 lesions (p = 0.110). Maximum concentration of contrast agent was reached after 180 min in both cartilage and menisci (except for grade 3 menisci where the maximum concentration was reached after 90 min). Conclusion: dGEMRIM and dGEMRIC may be feasible to combine in vivo, preferably with one examination before and one 2 h after contrast injection. Possible different dGEMRIM patterns at different stages of meniscus lesions must be taken into account when evaluating meniscus pathology

Myocardium assessment by relaxation along fictitious field, extracellular volume, feature tracking, and myocardial strain in hypertensive patients with left ventricular hypertrophy

Abstract Background: Previous research has shown impaired global longitudinal strain (GLS) and slightly elevated extracellular volume fraction (ECV) in hypertensive patients with left ventricular hypertrophy (HTN LVH). Up to now, only little attention has been paid to interactions between macromolecules and free water in hypertrophied myocardium. Purpose: To evaluate the feasibility of relaxation along a fictitious field with rank 2 (RAFF2) in HTN LVH patients. Study Type: Single institutional case control. Subjects: 9 HTN LVH (age, 69 ± 10 years) and 11 control subjects (age, 54 ± 12 years). Field Strength/Sequence: Relaxation time mapping (T1, T1p, and TRAFF2 with 11.8 μT maximum radio frequency field amplitude) was performed at 1.5 T using a Siemens Aera (Erlangen, Germany) scanner equipped with an 18-channel body array coil. Assessment: ECV was calculated using pre- and postcontrast T1, and global strains parameters were assessed by Segment CMR (Medviso AB Co, Sweden). The parametric maps of T1p and TRAFF2 were computed using a monoexponential model, while the Bloch-McConnell equations were solved numerically to model effect of the chemical exchange during radio frequency pulses. Statistical Tests: Parametric maps were averaged over myocardium for each subject to be used in statistical analysis. Kolmogorov-Smirnov was used as the normality test followed by Student’s t-test and Pearson’s correlation to determine the difference between the HTN LVH patients and controls along with Hedges’ g effect size and the association between variables, respectively. Results: TRAFF2 decreased statistically (83 ± 2 ms vs 88 ± 6 ms, P < 0.031), and global longitudinal strain was impaired (GLS, −14 ± 3 vs −18 ± 2, P < 0.002) in HTN LVH patients compared to the controls, respectively. Also, significant negative correlation was found between TRAFF2 and GLS (r = −0.53, P < 0.05). Data conclusion: Our results suggest that TRAFF2 decrease in HTN LVH patients may be explained by gradual collagen accumulation which can be reflected in GLS changes. Most likely, it increases the water proton interactions and consequently decreases TRAFF2 before myocardial scarring

Predicting osteoarthritis onset and progression with 3D texture analysis of cartilage MRI DESS:6-year data from osteoarthritis initiative

Abstract In this study, we developed a gray level co-occurrence matrix-based 3D texture analysis method for dual-echo steady-state (DESS) magnetic resonance (MR) images to be used for knee cartilage analysis in osteoarthritis (OA) studies and use it to study changes in articular cartilage between different subpopulations based on their rate of progression into radiographically confirmed OA. In total, 642 series of right knee DESS MR images at 3T were obtained from baseline, 36- and 72-month follow-ups from the OA Initiative database. At baseline, all 214 subjects included in the study had Kellgren-Lawrence (KL) grade <2. Three groups were defined, based on time of progression into radiographic OA (ROA) (KL grades ≥2): control (no progression), fast progressor (ROA at 36 months), and slow progressor (ROA at 72 months) groups. 3D texture analysis was used to extract textural features for femoral and tibial cartilages. All textural features, in both femur and tibia, showed significant longitudinal changes across all groups and tissue layers. Most of the longitudinal changes were observed in progressors, but significant changes were observed also in controls. Differences between groups were mostly seen at baseline and 72 months. The method is sensitive to cartilage changes before and after ROA. It was able to detect longitudinal changes in controls and progressors and to distinguish cartilage alterations due to OA and aging. Moreover, it was able to distinguish controls and different progressor groups before any radiographic signs of OA and during OA. Thus, texture analysis could be used as a marker for the onset and progression of OA

Validation and optimization of adiabatic T1ρ and T2ρ for quantitative imaging of articular cartilage at 3 T

Abstract Purpose: The aim of the present work was to validate and optimize adiabatic T1ρ and T2ρ mapping for in vivo measurements of articular cartilage at 3 Tesla (T). Methods: Phantom and in vivo experiments were systematically performed on a 3T clinical system to evaluate the sequences using hyperbolic secant HS1 and HS4 pulses. R1ρ and R2ρ relaxation rates were studied as a function of agarose and chondroitin sulfate concentration and pulse duration. Optimal in vivo protocol was determined by imaging the articular cartilage of two volunteers and varying the sequence parameters, and successively applied in eight additional subjects. Reproducibility was assessed in phantoms and in vivo. Results: Relaxation rates depended on agarose and chondroitin sulfate concentration. The sequences were able to generate relaxation time maps with pulse lengths of 8 and 6 ms for HS1 and HS4, respectively. In vivo findings were in good agreement with the phantoms. The implemented adiabatic T1ρ and T2ρ sequences demonstrated regional variation in relaxation time maps of femorotibial cartilage. Reproducibility in phantoms and in vivo was good to excellent for both adiabatic T1ρ and T2ρ. Conclusions: The findings indicate that sequences are suitable for quantitative in vivo assessment of articular cartilage at 3 T

Association between quantitative MRI and ICRS arthroscopic grading of articular cartilage

Abstract Purpose: To investigate the association of quantitative magnetic resonance imaging (qMRI) parameters with arthroscopic grading of cartilage degeneration. Arthroscopy of the knee is considered to be the gold standard of osteoarthritis diagnostics; however, it is operator-dependent and limited to the evaluation of the articular surface. qMRI provides information on the quality of articular cartilage and its changes even at early stages of a disease. Methods: qMRI techniques included T₁ relaxation time, T₂ relaxation time, and delayed gadolinium-enhanced MRI of cartilage mapping at 3 T in ten patients. Due to a lack of generally accepted semiquantitative scoring systems for evaluating severity of cartilage degeneration during arthroscopy, the International Cartilage Repair Society (ICRS) classification system was used to grade the severity of cartilage lesions. qMRI parameters were statistically compared to arthroscopic grading conducted with the ICRS classification system. Results: qMRI parameters were not linearly related to arthroscopic grading. Spearman’s correlation coefficients between qMRI and arthroscopic grading were not significant. The relative differences in qMRI parameters of superficial and deep cartilage varied with degeneration, suggesting different macromolecular alterations in different cartilage zones. Conclusions: Results suggest that loss of cartilage and the quality of remaining tissue in the lesion site may not be directly associated with each other. The severity of cartilage degeneration may not be revealed solely by diagnostic arthroscopy, and thus, qMRI can have a role in the investigation of cartilage degeneration

Assessment of articular cartilage of ankle joint in stable and unstable unilateral weber type-B/SER-type ankle fractures shortly after trauma using T2 relaxation time

Abstract Background: Early detection of post-traumatic cartilage damage in the ankle joint in magnetic resonance images can be difficult due to disturbances to structures usually appearing over time. Purpose: To study the articular cartilage of unilateral Weber type-B/SER-type ankle fractures shortly post-trauma using T2 relaxation time. Material and Methods: Fifty one fractured ankles were gathered from consecutively screened patients, compiled initially for RCT studies, and treated at Oulu University Hospital and classified as stable (n = 28) and unstable fractures (n = 23) based on external-rotation stress test: medial clear space of ≥5 mm was interpreted as unstable. A control group of healthy young individuals (n = 19) was also gathered. All ankles were imaged on average 9 (range: 1 to 25) days after injury on a 3.0T MRI unit for T2 relaxation time assessment, and the cartilage was divided into sub-regions for comparison. Results: Control group displayed significantly higher T2 values in tibial cartilage compared to stable (six out of nine regions, p-values = .003–.043) and unstable (six out of nine regions, p-values = .001–.037) ankle fractures. No differences were detected in talar cartilage. Also, no differences were observed between stable and unstable fractures in tibial or talar cartilage. Conclusions: Lower T2 relaxation times of tibial cartilage in fractured ankles suggest intact extra cellular matrix (ECM) of the cartilage. Severity of the ankle fracture, measured by ankle stability, does not seem to increase ECM degradation immediately after trauma

Elevated adiabatic T₁ρ and T₁ρ in articular cartilage are associated with cartilage and bone lesions in early osteoarthritis:a preliminary study

Abstract Purpose: To evaluate adiabatic T₁ρ and T₂ρ of articular cartilage in symptomatic osteoarthritis (OA) patients and asymptomatic volunteers, and to determine their association with magnetic resonance imaging (MRI)‐based structural abnormalities in cartilage and bone. Materials and Methods: A total of 24 subjects (age range: 50–68 years; 12 female) were enrolled, including 12 early OA patients and 12 volunteers with normal joint function. Patients and volunteers underwent 3T MRI. T₂ρ, adiabatic T₁ρ, and T₂ρ relaxation times of knee articular cartilage were measured. Proton density (PD)‐ and T₁‐weighted MR image series were also obtained and separately evaluated for morphological changes using the MRI OA Knee Scoring (MOAKS) system. Comparisons using the Mann–Whitney nonparametric test were performed after dividing the study participants according to physical symptoms as determined by Western Ontario and McMaster Universities (WOMAC) score or presence of cartilage lesions, bone marrow lesions, or osteophytes. Results: Elevated adiabatic T₁ρ and T₂ρ relaxation times of articular cartilage were associated with cartilage loss (P = 0.024–0.047), physical symptoms (0.0068–0.035), and osteophytes (0.0039–0.027). Elevated adiabatic T₁ρ was also associated with bone marrow lesions (0.033). Conclusion: Preliminary data suggest that elevated adiabatic T₁ρ and T₂ρ of cartilage are associated with morphological abnormalities of cartilage and bone, and thus may be applicable for in vivo OA research and diagnostics