gagCEST imaging at 3 T MRI in patients with articular cartilage lesions of the knee and intraoperative validation.

OBJECTIVE: The aim of this study was to compare glycosaminoglycan chemical exchange saturation transfer (gagCEST) of knee cartilage with intraoperative results for the assessment of early osteoarthritis (OA) and to define gagCEST values for the differentiation between healthy and degenerated cartilage. DESIGN: Twenty-one patients with cartilage lesions or moderate OA were examined using 3 T Magnetic Resonance Imaging (MRI). In this prospective study, regions of interest (ROIs) were examined by a sagittal gagCEST analysis and a morphological high-resolution three-dimensional, fat-saturated proton-density space sequence. Cartilage lesions were identified arthroscopically, graded by the International Cartilage Repair Society (ICRS) score in 42 defined ROIs per patient and consecutively compared with mean gagCEST values using analysis of variance and Spearman's rank correlation test. Receiver operating characteristics (ROC) curves were applied to identify gagCEST threshold values to differentiate between the ICRS grades. RESULTS: A total of 882 ROIs were examined and graduated in ICRS score 0 (67.3%), 1 (25.2%), 2 (6.2%) and the merged ICRS 3 and 4 (1.0%). gagCEST values decreased with increasing grade of cartilage damage with a negative correlation between gagCEST values and ICRS scores. A gagCEST value threshold of 3.55% was identified to differentiate between ICRS score 0 (normal) and all other grades. CONCLUSIONS: gagCEST reflects the content of glycosaminoglycan and might provide a diagnostic tool for the detection of early knee-joint cartilage damage and for the non-invasive subtle differentiation between ICRS grades by MRI even at early stages in clinical practice.

Prediction of response to Certolizumab-Pegol in rheumatoid arthritis (PreCePRA) by functional MRI of the brain - Study protocol for a randomized double-blind controlled study.

BACKGROUND: Tumor necrosis factor inhibitors (TNFi) signify a major advance in the treatment of rheumatoid arthritis (RA). However, treatment success initially remains uncertain as approximately half of the patients do not respond adequately to TNFi. Thus, an unmet need exists to better predict therapeutic outcome of biologicals. OBJECTIVES: We investigated whether brain activity associated with arthritis measured by functional magnetic resonance imaging (fMRI) of the brain can serve as a predictor of response to TNFi in RA patients. METHODS: PreCePRA is a multi-center, randomized, double-blind, placebo-controlled fMRI trial on patients with RA [1] [2]. Active RA patients failing csDMARDs therapy with a DAS28 > 3.2 and at least three tender and/or swollen joints underwent a brain BOLD (blood-oxygen-level dependent) fMRI scan upon joint compression at screening. Patients were then randomized into a 12-week double-blinded treatment phase with 200 mg Certolizumab Pegol (CZP) every two weeks (arm 1: fMRI BOLD signal activated volume > 2000 voxel, i.e. 2 cm3; arm 2: fMRI BOLD signal activated volume <2000 voxel) or placebo (arm 3). DAS28 low disease activity at 12 weeks was assigned as primary endpoint. A 12-week follow-up phase in which patients were switched from the placebo to the treatment arm followed the blinded phase. fMRI was carried out at screening as well as after 12 and 24 weeks of receiving CZP or placebo. CONCLUSION: We hypothesize that high-level central nervous representation of pain in patients with rheumatoid arthritis predicts response to the TNFi CZP which we further investigate in the PreCePRA trial.

[Imaging of psoriatic arthritis and aspects of radiographic progression]. / Bildgebung bei der Psoriasisarthritis und Aspekte der röntgenologischen Progression.

Psoriatic arthritis (PsA) is a heterogeneous multifactorial disease with musculoskeletal involvement, which can be manifested as monoarthritis, oligoarthritis or polyarthritis and in some patients can also affect the axial skeleton. The most frequent indications of inflammation are bone marrow edema and enthesitis. The early and differential diagnosis of PsA is a clinical challenge, particularly as a differential diagnosis from other inflammatory or degenerative diseases of joints. Inflammatory joint and tendon alterations in the region of the extremities and the spine can be visualized with high sensitivity by the use of magnetic resonance imaging (MRI), musculoskeletal sonography (US) and fluorescence optical imaging (FOI). The use of MRI has a prognostic value with respect to the further radiographic course of the disease, particularly in the initial stages of the disease. Structural damage can be specifically and also partially demonstrated 3­dimensionally in peripheral joints and the spine by the use of computed tomography (CT) and conventional X­ray imaging. High-resolution peripheral quantitative CT (HR-pQCT) in particular, can visualize pathophysiological processes and the morphological consequences even in early stages of the disease. The values of conventional X­ray diagnostics, CT, MRI, musculoskeletal US and alternative imaging procedures are presented with respect to the diagnostics and prognosis of the progression of patients with PsA.