Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94143, USA.
Osteoarthritis Cartilage. 2011 Jan;19(1):65-73. doi: 10.1016/j.joca.2010.10.023. Epub 2010 Oct 31.
To study the role of vastus lateralis/vastus medialis cross-sectional area CSA ratio (VL/VM CSA ratio) in preclinical knee osteoarthritis (OA) using magnetic resonance imaging (MRI)-based cartilage T2 mapping technique and morphological analysis at 3.0T in non-symptomatic, middle-aged subjects.
174 non-symptomatic individuals aged 45-55 years with OA risk factors were selected from the Osteoarthritis Initiative (OAI) incidence cohort. OA-related knee abnormalities were analyzed using the whole-organ magnetic resonance imaging score (WORMS). Knee cartilage T2 maps were generated using sagittal 2D multi-echo spin-echo images of the right knee. CSA of thigh muscles was measured using axial T1W images of the right mid thigh. Spline-based segmentation of cartilage and muscles was performed on a SUN/SPARC workstation. Muscle measurements were normalized to body size using body surface area (BSA). Statistical significance was determined using Student's t-test, Pearson correlation test, and multiple regression models. To correct for multiple testing, Bonferroni adjustments were applied across all tests within each of the primary results tables (Tables III-VII).
Higher T2 values were associated with increased prevalence and severity of cartilage degeneration. In our study, male and female subjects with higher VL/VM CSA ratio demonstrated significantly lower mean cartilage T2 values (all compartments combined) (mean 44.10 vs 45.17, P=0.0017), and significantly lower WORMS scores (mean 14.12 vs 18.68, P=0.0316). Regression analyses of combined mean cartilage T2 using VL/VM CSA ratio as a continuous predictor showed a significant curvilinear relationship between these two variables (P=0.0082).
Our results suggested that higher VL/VM CSA ratio is associated with lower T2 values and decreased presence and severity of OA-related morphological changes. Additional studies will be needed to determine causality.
使用基于磁共振成像（MRI）的软骨 T2 映射技术和 3.0T 下形态分析，研究股外侧肌/股内侧肌横截面积比（VL/VM CSA 比）在非症状性、中年人群中早期膝骨关节炎（OA）中的作用。
从骨关节炎倡议（OAI）发病队列中选择了 174 名年龄在 45-55 岁、有 OA 危险因素的非症状个体。使用全器官磁共振成像评分（WORMS）分析与 OA 相关的膝关节异常。使用右膝矢状 2D 多回波自旋回波图像生成膝关节软骨 T2 图。使用右大腿中段的轴向 T1W 图像测量股四头肌 CSA。在 SUN/SPARC 工作站上对软骨和肌肉进行基于样条的分割。使用体表面积（BSA）对肌肉测量值进行体型标准化。使用 Student's t 检验、Pearson 相关检验和多元回归模型确定统计学意义。为了校正多重检验，对每个主要结果表（表 III-VII）中的所有检验都应用了 Bonferroni 调整。
较高的 T2 值与软骨退变的患病率和严重程度增加相关。在我们的研究中，VL/VM CSA 比较高的男性和女性受试者的平均软骨 T2 值（所有节段合并）明显较低（分别为 44.10 与 45.17，P=0.0017），WORMS 评分也明显较低（分别为 14.12 与 18.68，P=0.0316）。使用 VL/VM CSA 比作为连续预测因子对合并平均软骨 T2 进行回归分析显示，这两个变量之间存在显著的曲线关系（P=0.0082）。
我们的结果表明，较高的 VL/VM CSA 比与较低的 T2 值以及与 OA 相关的形态学变化的发生和严重程度降低有关。需要进一步的研究来确定因果关系。
