Nielsen Flemming K, Egund Niels, Jørgensen Anette, Peters David A, Jurik Anne Grethe
Department of Radiology, Aarhus University Hospital, Noerrebrogade 44, 8000, Aarhus, Denmark.
Department of Rheumatology, Aarhus University Hospital, Noerrebrogade 44, 8000, Aarhus, Denmark.
BMC Musculoskelet Disord. 2016 Nov 16;17(1):479. doi: 10.1186/s12891-016-1336-9.
Bone marrow lesions (BMLs) in knee osteoarthritis (OA) can be assessed using fluid sensitive and contrast enhanced sequences. The association between BMLs and symptoms has been investigated in several studies but only using fluid sensitive sequences. Our aims were to assess BMLs by contrast enhanced MRI sequences in comparison with a fluid sensitive STIR sequence using two different segmentation methods and to analyze the association between the MR findings and disability and pain.
Twenty-two patients (mean age 61 years, range 41-79 years) with medial femoro-tibial knee OA obtained MRI and filled out a WOMAC questionnaire at baseline and follow-up (median interval of 334 days). STIR, dynamic contrast enhanced-MRI (DCE-MRI) and fat saturated T1 post-contrast (T1 CE FS) MRI sequences were obtained. All STIR and T1 CE FS sequences were assessed independently by two readers for STIR-BMLs and contrast enhancing areas of BMLs (CEA-BMLs) using manual segmentation and computer assisted segmentation, and the measurements were compared. DCE-MRIs were assessed for the relative distribution of voxels with an inflammatory enhancement pattern, N, in the bone marrow. All findings were compared to WOMAC scores, including pain and overall symptoms, and changes from baseline to follow-up were analyzed.
The average volume of CEA-BML was smaller than the STIR-BML volume by manual segmentation. The opposite was found for computer assisted segmentation where the average CEA-BML volume was larger than the STIR-BML volume. The contradictory finding by computer assisted segmentation was partly caused by a number of outliers with an apparent generally increased signal intensity in the anterior parts of the femoral condyle and tibial plateau causing an overestimation of the CEA-BML volume. Both CEA-BML, STIR-BML and N were significantly correlated with symptoms and to a similar degree. A significant reduction in total WOMAC score was seen at follow-up, but no significant changes were observed for either CEA-BML, STIR-BML or N.
Neither the degree nor the volume of contrast enhancement in BMLs seems to add any clinical information compared to BMLs visualized by fluid sensitive sequences. Manual segmentation may be needed to obtain valid CEA-BML measurements.
膝关节骨关节炎（OA）中的骨髓病变（BMLs）可通过液体敏感序列和对比增强序列进行评估。多项研究对BMLs与症状之间的关联进行了调查，但仅使用了液体敏感序列。我们的目的是通过对比增强MRI序列评估BMLs，并与使用两种不同分割方法的液体敏感短反转恢复（STIR）序列进行比较，同时分析磁共振成像（MRI）结果与残疾和疼痛之间的关联。
22例股骨内侧髁-胫骨膝关节OA患者（平均年龄61岁，范围41 - 79岁）在基线和随访时（中位间隔334天）接受了MRI检查并填写了西安大略和麦克马斯特大学骨关节炎指数（WOMAC）问卷。获取了STIR、动态对比增强MRI（DCE-MRI）和脂肪饱和T1加权对比增强（T1 CE FS）MRI序列。两名阅片者分别使用手动分割和计算机辅助分割独立评估所有STIR和T1 CE FS序列的STIR-BMLs和BMLs的对比增强区域（CEA-BMLs），并比较测量结果。评估DCE-MRIs中骨髓内具有炎症增强模式的体素相对分布N。将所有结果与WOMAC评分（包括疼痛和总体症状）进行比较，并分析从基线到随访的变化。
通过手动分割，CEA-BML的平均体积小于STIR-BML体积。在计算机辅助分割中发现相反情况，即CEA-BML的平均体积大于STIR-BML体积。计算机辅助分割的矛盾结果部分是由于一些异常值导致，这些异常值在股骨髁和胫骨平台前部的信号强度明显普遍增加，从而导致CEA-BML体积的高估。CEA-BML、STIR-BML和N均与症状显著相关且程度相似。随访时WOMAC总分显著降低，但CEA-BML、STIR-BML或N均未观察到显著变化。
与通过液体敏感序列显示的BMLs相比，BMLs的对比增强程度和体积似乎并未增加任何临床信息。可能需要手动分割来获得有效的CEA-BML测量值。
