Menzies Research Institute, University of Tasmania, Private Bag 23, Hobart, Tasmania, 7000, Australia,
Clin Rheumatol. 2014 Mar;33(3):359-68. doi: 10.1007/s10067-013-2447-4. Epub 2013 Dec 10.
This study aims to assess mean signal intensity of cartilage on T1-weighted magnetic resonance imaging (MRI) images, and then examine whether mean signal intensity is associated with risk factors and measures of osteoarthritis in younger and older adults. A total of 50 younger adult subjects (mean age 41, range 29-57; 64% female; baseline only) and 168 older adult subjects (mean age 63, range 52-78; 46% female; baseline and 2.9 year followup) were randomly selected from the community. T1-weighted fat-supressed gradient recall echo MRI scans of right knees were performed. Image segmentation was performed semi-automatically, and measures of mean signal intensity and cartilage thickness for regions of cartilage were obtained. Urinary levels of C-terminal crosslinking telopeptide of type II collagen (U-CTX-II) were measured in younger adults. Cartilage defects were scored using a 5-point scale in both groups. In multivariable analyses, higher cartilage defects and BMI were significantly associated with lower same-region mean signal intensity in younger and older adults. CTX-II was negatively and significantly associated with mean signal intensity of cartilage in the lateral femoral and patellar sites. Joint space narrowing and osteophytes analysed in older adults were significantly associated with reduced mean signal intensity at various sites. Over 2.9 years, lower mean signal intensity at femoral and patellar sites and in whole knee was associated with decreases in cartilage thickness. Reduced mean signal intensity of cartilage on T1-weighted gradient recall echo MRI is associated with osteoarthritis risk factors and predicts cartilage loss suggesting low cartilage signal intensity may reflect early osteoarthritic changes.
本研究旨在评估 T1 加权磁共振成像（MRI）图像上软骨的平均信号强度，然后检查平均信号强度是否与年轻和老年患者的骨关节炎危险因素和测量指标相关。本研究共纳入 50 名年轻成年受试者（平均年龄 41 岁，范围 29-57 岁；64%为女性；仅基线）和 168 名老年成年受试者（平均年龄 63 岁，范围 52-78 岁；46%为女性；基线和 2.9 年随访）。这些受试者均来自社区。对右膝关节进行 T1 加权脂肪抑制梯度回波 MRI 扫描。采用半自动图像分割技术，获取软骨区域的平均信号强度和软骨厚度测量值。在年轻成年受试者中，检测 2 型胶原 C 端交联肽（U-CTX-II）的尿水平。两组均采用 5 分制评分评估软骨缺损。多变量分析显示，在年轻和老年患者中，较高的软骨缺损和 BMI 与较低的同一区域平均信号强度显著相关。CTX-II 与外侧股骨和髌骨部位软骨的平均信号强度呈显著负相关。在老年患者中，关节间隙狭窄和骨赘与各部位平均信号强度降低显著相关。经过 2.9 年，股骨和髌骨部位以及全膝关节的平均信号强度降低与软骨厚度减少相关。T1 加权梯度回波 MRI 上软骨的平均信号强度降低与骨关节炎的危险因素相关，并且预测了软骨丢失，提示低软骨信号强度可能反映了早期骨关节炎的变化。
