Riis Robert Gc
Dan Med J. 2018 Apr;65(4).
Knee osteoarthritis (KOA) is one of the most common causes of physical disability in the elderly population. With an increasing ageing and obese population, the prevalence of KOA is expected to rise substantially. The needs for a better understanding of the disease and tools that can predict the course of the disease, for example following treatment, are therefore imperative. Inflammation has over the last years been recognised as an important factor for both the symptomatology and disease course in KOA. Synovitis, inflammation of the synovium, is the hallmark of intra-articular inflammation and has been associated with pain, symptoms and disease progression. Synovitis can be visualised on conventional static MRI. However, the addition of a dynamic contrast-enhanced (DCE) MRI-sequence enables the assessment of the synovium both in regards of its morphology and perfusion. Studies in both KOA and rheumatoid arthritis have shown that DCE-MRI measures of synovitis are more sensitive than conventional static MRI in regards of microscopic synovitis and patient-reported outcome measures (PROMs). The aims of this PhD project were to characterise synovitis in KOA with conventional static and DCE MRI in regards of histology (study I), its association with PROMs (studies II-III) and changes following a symptoms-improving intervention (study III). We found that DCE-MRI-measures of synovitis seem to be superior to conventional static MRI in their association with histological synovitis (study I) and pain (study II) in a cross-sectional setting. However, the use of DCE-MRI over conventional static CE-MRI cannot be justified when assessing the long-term changes in synovitis following an intervention with intra-articular corticosteroids/placebo and exercise (study III). Evidence is mounting that KOA is constituted of different phenotypes. There is an urgent need to define these in order to improve and individualise treatment and management. It is essential to gain a better understanding of the different pro-cesses taking place in KOA, on an individual level and in the different stages of the disease. DCE-MRI may very well be a useful tool in facing these challenges especially in regards of the role of perfusion and inflammation in KOA and osteoarthri-tis in general.
膝关节骨关节炎（KOA）是老年人群身体残疾的最常见原因之一。随着老龄化和肥胖人口的增加，KOA的患病率预计将大幅上升。因此，迫切需要更好地了解这种疾病以及能够预测疾病进程的工具，例如在治疗后。
近年来，炎症已被认为是KOA症状和疾病进程的一个重要因素。滑膜炎，即滑膜的炎症，是关节内炎症的标志，并与疼痛、症状和疾病进展相关。滑膜炎可以在传统的静态MRI上显示出来。然而，添加动态对比增强（DCE）MRI序列能够在形态学和灌注方面评估滑膜。在KOA和类风湿性关节炎的研究都表明，就微观滑膜炎和患者报告的结局指标（PROMs）而言，DCE-MRI对滑膜炎的测量比传统静态MRI更敏感。
本博士项目的目的是通过传统静态和DCE MRI在组织学方面（研究I）、与PROMs的关联方面（研究II-III）以及症状改善干预后的变化方面（研究III）来表征KOA中的滑膜炎。我们发现，在横断面研究中，DCE-MRI对滑膜炎的测量在与组织学滑膜炎（研究I）和疼痛（研究II）的关联方面似乎优于传统静态MRI。然而，在评估关节内注射皮质类固醇/安慰剂和运动干预后滑膜炎的长期变化时，使用DCE-MRI而非传统静态CE-MRI是不合理的（研究III）。
越来越多的证据表明，KOA由不同的表型组成。迫切需要对这些表型进行定义，以改善治疗和管理并实现个体化。必须在个体层面和疾病的不同阶段更好地了解KOA中发生的不同过程。DCE-MRI很可能是应对这些挑战的有用工具，特别是在灌注和炎症在KOA及一般骨关节炎中的作用方面。
