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PurposeTo quantitatively evaluate longitudinal changes in water and lipid in knee bone marrow with and without bone marrow edema-like lesions (BMELs) in subjects with acutely ruptured anterior cruciate ligaments (ACLs) or osteoarthritis (OA) using three-dimensional magnetic resonance spectroscopic imaging (3D MRSI).Material and methodsTen ACL and 10 OA subjects who presented with BMEL and seven BMEL-free controls were scanned at 3T. All ACL and OA subjects had one-year follow-up scans. 3D MRSI was acquired in BMEL and adjacent bone marrow, and water content (WC) and unsaturated lipid index (UI) were calculated in each region of interest.ResultsAt baseline, ACL BMEL WC was significantly higher than ACL non-BMEL, OA BMEL, and control WC; ACL non-BMEL WC, ACL BMEL UI, and OA BMEL WC were significantly higher than control. ACL BMEL WC decreased significantly one year post-reconstruction; UI decreased non-significantly (p=0.09). No significant changes in OA BMEL or ACL and OA non-BMEL WC and UI were observed.Conclusion3D MRSI is a powerful method of quantitatively assessing the biochemical composition of bone marrow in OA and ACL-injured knees, which may serve as imaging markers to improve comprehension of primary and secondary OA pathology.

BackgroundThe effectiveness of anterior cruciate ligament (ACL) reconstruction in preventing early osteoarthritis is debated. Restoring the original biomechanics may potentially prevent degeneration, but apparent pathomechanisms have yet to be described. Newer quantitative magnetic resonance (qMR) imaging techniques, specifically T1ρ and T2, offer novel, noninvasive methods of visualizing and quantifying early cartilage degeneration.PurposeTo determine the tibiofemoral biomechanical alterations before and after ACL reconstruction using magnetic resonance imaging (MRI) and to evaluate the association between biomechanics and cartilage degeneration using T1ρ and T2.Study designCohort study; Level of evidence, 2.MethodsKnee MRIs of 51 individuals (mean age, 29.5 ± 8.4 years) with unilateral ACL injuries were obtained prior to surgery; 19 control subjects (mean age, 30.7 ± 5.3 years) were also scanned. Follow-up MRIs were obtained at 6 months and 1 year. Tibial position (TP), internal tibial rotation (ITR), and T1ρ and T2 were calculated using an in-house Matlab program. Student t tests, repeated measures, and regression models were used to compare differences between injured and uninjured sides, observe longitudinal changes, and evaluate correlations between TP, ITR, and T1ρ and T2.ResultsTP was significantly more anterior on the injured side at all time points (P < .001). ITR was significantly increased on the injured side prior to surgery (P = .033). At 1 year, a more anterior TP was associated with elevated T1ρ (P = .002) and T2 (P = .026) in the posterolateral tibia and with decreased T2 in the central lateral femur (P = .048); ITR was associated with increased T1ρ in the posteromedial femur (P = .009). ITR at 6 months was associated with increased T1ρ at 1 year in the posteromedial tibia (P = .029).ConclusionPersistent biomechanical alterations after ACL reconstruction are related to significant changes in cartilage T1ρ and T2 at 1 year postreconstruction. Longitudinal correlations between ITR and T1ρ suggest that these alterations may be indicative of future cartilage injury, leading to degeneration and osteoarthritis.Clinical relevanceNewer surgical techniques should be developed to eliminate the persistent anterior tibial translation commonly seen after ACL reconstruction. qMR will be a useful tool to evaluate the ability of these newer techniques to prevent cartilage changes.

PurposeTo develop and compare with the classical region of interest (ROI)-based approach a fully automatic, local, and unbiased way of studying the knee T1ρ relaxation time by creating an atlas and using voxel-based relaxometry (VBR) in osteoarthritis (OA) and anterior cruciate ligament (ACL) subjects.Materials and methodsIn this study 110 subjects from two cohorts: 1) Mild OA 40 patients with mild-OA Kellgren-Lawrence (KL) ≤ 2 and 15 controls KL ≤ 1; 2) ACL cohort (a model for early OA): 40 ACL-injured patients imaged prior to ACL reconstruction and 1-year postsurgery and 15 controls are analyzed. All the subjects were acquired at 3T with a protocol that includes: 3D-FSE (CUBE) and 3D-T1ρ . A nonrigid registration technique was applied to align all the images on a single template. This allows for performing VBR to assess local statistical differences of T1ρ values using z-score analysis. VBR results were compared with those obtained with classical ROI-based technique.ResultsROI-based results from atlas-based segmentation were consistent with classical ROI-based method (coefficient of variation [CV] = 3.83%). Voxel-based group analysis revealed local patterns that were overlooked by the ROI-based approach; eg, VBR showed posterior lateral femur and posterior lateral tibia significant T1ρ elevations in ACL-injured patients (sample mean z-score=9.7 and 10.3). Those elevations were overlooked by the classical ROI-based approach (sample mean z-score=1.87 and -1.73) CONCLUSION: VBR is a feasible and accurate tool for the local evaluation of the biochemical composition of knee articular cartilage. VBR is capable of detecting specific local patterns on T1ρ maps in OA and ACL subjects.

This study assessed the effects of static loading on MRI relaxation times of menisci in individuals with and without radiographic knee OA. High-resolution fast spin-echo (FSE) and T(1ρ)/T(2) relaxation time MR sequences were obtained with and without loading at 50% body weight in 124 subjects. T(1ρ)/T(2) relaxation times were calculated in menisci, and meniscus lesions were assessed through clinical grading. Student's t-test compared OA and control unloaded relaxation times as well as within-group changes with loading, Generalized Linear Models evaluated zonal variation, and ANCOVA compared loading response between groups. Unloaded T(1ρ) and T(2) in the middle and inner zones of the lateral anterior horn and outer zone of the medial posterior horn were significantly higher in OA and suggest that meniscal OA change occurs unevenly. Zonal T(1ρ) and T(2) showed differing patterns between anterior and posterior horns, suggesting differences in macromolecular organization. Significant increases with loading were seen largely in the T(2) of controls and less frequently in subjects with OA. In the medial posterior horn, T(1ρ) and T(2) decreased with loading in OA but changed negligibly in controls; these significantly different loading responses between groups may indicate load transmission failure in OA menisci.

This study is to evaluate highly accelerated three-dimensional (3D) dynamic contrast-enhanced (DCE) wrist MRI for assessment of perfusion in rheumatoid arthritis (RA) patients. A pseudo-random variable-density undersampling strategy, circular Cartesian undersampling (CIRCUS), was combined with k-t SPARSE-SENSE reconstruction to achieve a highly accelerated 3D DCE wrist MRI. Two healthy volunteers and 10 RA patients were studied. Two patients were on methotrexate (MTX) only (Group I) and the other eight were treated with a combination therapy of MTX and anti-tumor necrosis factor (TNF) therapy (Group II). Patients were scanned at baseline and 3 month follow-up. DCE MR images were used to evaluate perfusion in synovitis and bone marrow edema pattern in the RA wrist joints. A series of perfusion parameters was derived and compared with clinical disease activity scores of 28 joints (DAS28). 3D DCE wrist MR images were obtained with a spatial resolution of 0.3 × 0.3 × 1.5 mm(3) and temporal resolution of 5 s (with an acceleration factor of 20). The derived perfusion parameters, most notably transition time (dT) of synovitis, showed significant negative correlations with DAS28-ESR (r = -0.80, p

BackgroundMultiple techniques are used for femoral tunnel drilling in ACL reconstruction, including the Mini-two Incision Method (MT) and Anteromedial Portal Technique (AM). Both techniques allow for independent placement of the femoral tunnel, though there are no reports comparing kinematics and cartilage health after these reconstructions. We hypothesized that both techniques would result in the restoration of normal knee kinematics and show no evidence of early cartilage degeneration.MethodsA total of 20 patients were evaluated one year after ACL reconstruction, including 10 patients after MT and 10 patients after AM. MR-imaging was acquired bilaterally with the knee loaded in extension and flexion to evaluate the kinematics of the reconstructed knee compared with the normal knee. Quantitative cartilage imaging was obtained and compared with 10 matched control subjects. The Marx Activity Rating Scale and KOOS survey were administered.ResultsThe tibia was positioned significantly more anteriorly in extension and flexion relative to the contralateral knee for the MT group. The tibial position in the AM group was not significantly different from the patient's contralateral knee. T1ρ values in the central-medial tibia were significantly elevated in the MT group compared with the Control group. KOOS Symptom scores were significantly better for the MT group compared with the AM group.ConclusionsWe have observed in vivo differences in knee kinematics and early cartilage degeneration between patients following MT and AM ACL reconstructions. Both techniques allow for anatomic ACL reconstruction, though the MT group shows significant early differences compared with the patient's normal knee.

Osteosarcoma (OS) is a common malignant tumor in the world. Circular RNAs are endogenous non-coding RNAs that have been linked to the development of cancer. However, the role of circ_001569 in OS progression is still unclear. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of circ_001569, microRNA-185-5p (miR-185-5p) and flotillin-2 (FLOT2). The abilities of cell proliferation, migration and invasion were evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and Transwell assays, respectively. Also, western blot analysis was performed to assess the levels of epithelial–mesenchymal transition (EMT)-related proteins and FLOT2 protein. Besides, the dual-luciferase reporter assay was used to verify the interactions among circ_001569, miR-185-5p and FLOT2. Circ_001569 expression was increased in OS tissues and cells, and its knockdown reduced the proliferation, migration, invasion and EMT of OS cells. MiR-185-5p could interact with circ_001569. Inhibition of miR-185-5p could recover the suppression effects of silenced-circ_001569 on the proliferation and metastasis of OS cells. Furthermore, FLOT2 was a target of miR-185-5p. Overexpressed FLOT2 could restore the inhibition effects of miR-185-5p mimic on the proliferation and metastasis of OS cells. Also, FLOT2 expression was regulated by circ_001569 and miR-185-5p. In addition, circ_001569 knockdown also reduced the OS tumor growth in vivo. Circ_001569 might act as an oncogene in OS progression by regulating the miR-185-5p/FLOT2 axis, which provided a reliable new approach for the treatment of OS patients.